Canada Metal "Martyr" anode

[John R.]

I spoke with Canada Metal today and was given the complete run down on the Martyr prop zinc anode sold by West Marine.

Basically it is a very similar design to the Electro-Guard and as such is also vulnerable to the zinc shell retaining screw coming loose due to decomposition of the zinc. They recognize this anomaly and deal with this potential problem by using what they term a "nylon patch hex fastener". What that means is they have the fastener threads coated with nylon which basically acts like a nyloc hex nut and won't vibrate loose. The caveat though is that there is nothing to prevent the zinc from decomposing under the fastener head. The same design problem exists with the Electro-Guard from discussions I've had with people today that have and do use them.

Canada metal advises that the end of the zinc (area under the fastener head) be painted with a couple of coats of bottom paint. They say their experience and lab tests have shown that it keeps the zinc from decomposing in that area from the insulation afforded by the paint. In theory it sounds reasonable except when one considers the copper content of the paint in contact with the zinc surface and the fastener.

It seems to me that both the Martyr and the Electro-Guard are equally prone to the same potential pitfall of possibly coming loose because of the same reason. The good news is that at least the zinc replacement sleeve is relatively cheap when compared to the cost of an entire Perry Nut when they were available. The Perry Nut was problem free however.

The advantage of the Martyr over the E-G is that because of the nylon coated fastener the zinc sleeve can be replaced under water and yet still be secure. Where with the E-G you need to use a loctite, caulk or similar on the fastener threads to keep it secured which can't be used under water if the zinc sleeve needs changing between haulouts.

The downside to the Martyr is that it uses a black mild steel fastener instead of stainless to secure the zinc sleeve in position. That means it will oxidize (rust) when the boat is out of the water. It is fine if it is kept underwater and protected by the zinc that it retains in position. I was told they are in the process of changing that fastener to stainless but the general public will not see that version for about 8 months unless it is special ordered. Of course the fastener can just be replaced with a stainless one but it won't have the nylon coating on the threads to secure it.

They said that all zinc replacement sleeves will be furnished with a new nylon coated fastener. Once these fasteners are installed and then removed they should be discarded as the nylon coating on the threads obviously will no longer be effective.

Hope this info is of help for anyone seeking a substitution for the good old Perry Nut.

[Tom]

I spoke with Canada Metal today and was given the complete run down on the Martyr prop zinc anode sold by West Marine.

Basically it is a very similar design to the Electro-Guard and as such is also vulnerable to the zinc shell retaining screw coming loose due to decomposition of the zinc. They recognize this anomaly and deal with this potential problem by using what they term a "nylon patch hex fastener". What that means is they have the fastener threads coated with nylon which basically acts like a nyloc hex nut and won't vibrate loose. The caveat though is that there is nothing to prevent the zinc from decomposing under the fastener head. The same design problem exists with the Electro-Guard from discussions I've had with people today that have and do use them.

Canada metal advises that the end of the zinc (area under the fastener head) be painted with a couple of coats of bottom paint. They say their experience and lab tests have shown that it keeps the zinc from decomposing in that area from the insulation afforded by the paint. In theory it sounds reasonable except when one considers the copper content of the paint in contact with the zinc surface and the fastener.

It seems to me that both the Martyr and the Electro-Guard are equally prone to the same potential pitfall of possibly coming loose because of the same reason. The good news is that at least the zinc replacement sleeve is relatively cheap when compared to the cost of an entire Perry Nut when they were available. The Perry Nut was problem free however.

The advantage of the Martyr over the E-G is that because of the nylon coated fastener the zinc sleeve can be replaced under water and yet still be secure. Where with the E-G you need to use a loctite, caulk or similar on the fastener threads to keep it secured which can't be used under water if the zinc sleeve needs changing between haulouts.

The downside to the Martyr is that it uses a black mild steel fastener instead of stainless to secure the zinc sleeve in position. That means it will oxidize (rust) when the boat is out of the water. It is fine if it is kept underwater and protected by the zinc that it retains in position. I was told they are in the process of changing that fastener to stainless but the general public will not see that version for about 8 months unless it is special ordered. Of course the fastener can just be replaced with a stainless one but it won't have the nylon coating on the threads to secure it.

They said that all zinc replacement sleeves will be furnished with a new nylon coated fastener. Once these fasteners are installed and then removed they should be discarded as the nylon coating on the threads obviously will no longer be effective.

Hope this info is of help for anyone seeking a substitution for the good old Perry Nut.

John, Thanks for the info. Doesn't painting the end of the zinc create an insulator between the zinc and prop shaft? If you are of the school that believes the star washer was used to insure good contact between the zinc, the bolt and the prop shaft, then you are defeating the whole reason for the star washer (and interrupting the continuity). Unless you believe that the copper in the bottom paint provides enough continuity to pass a week electric current. I'd be skeptical about this until proven to me.

I'd be inclined to go with a ss bolt replacement unless they're using a non-standard thread. BTW 5200 does set underwater and can be used underwater - the directions even say you can spray it with water to speed curing. However it IS a lot of fuss. On the other hand the last diver I hired to change my EG zinc in the water crossthreaded the bronze nut and couldn't tighten the bolt up against the star washer or the zinc. I found out at the next haulout that the zinc was slammming around down there with a quarter inch of play. A friend of mine hired a diver to do his zinc and the diver told him he had dropped the bolt so couldn't put the zinc on, but he'd get another bolt and come back and do it. He later told him he had, but at haulout he discovered the diver hadn't and he'd been without a zinc for at leat four months. Changing zincs in the water is a tricky business at best with the electro guard system. Maybe in real clear, warm water, but in most marinas it's a last choice for me.

I'd plan to do it at haulout where you can stand comfortably with perfect vision and pick it up if you drop it. Thus the question of how hard it would be to do in the water I don't think should be factored into one's reasoning. I think we should think in terms of what's best just assuming it can be done right. If you drop your plastic tipped bolt, you're going to play hell getting one at the local chandlery too. The question is, are you even going to be able to get Electro Guard zincs if the retailers switch to something else? Perhaps EG will go the way of the Perry Nut.

Final thought - MILD steel? Bronze and Stainless are fairly close on the galvanic scale. Bronze and mild steel are not close on the galvanic scale. Sure, it might not rust underwater if not exposed to air, but how about the galvanic potential? If your bronze prop and stainless shaft eat that rust free mild steel bolt, the plastic tips that are left won't hold your zinc on. Some of you metallurical wizards straighten me out on this. Is it OK to put mild steel up against bronze under salt water?



TomCambria@mindspring.com

[len]

i've used the shaft zincs from west marine from years and never had one fall off - they tend to decay from the outside and stay fairly tight on the inside - as others have written, i do put a little life-caulk on the end of the nut

len



md.frel@nwh.org

[Tom]

i've used the shaft zincs from west marine from years and never had one fall off - they tend to decay from the outside and stay fairly tight on the inside - as others have written, i do put a little life-caulk on the end of the nut

len

Len, So have I but what are you going to do if we can't get the electro-guard zincs any more? Do you feel OK about the mild steel bolt? BTW I've never understood the idea of putting Lifecaulk on the bolt. 5200 is a polyurethane ADHESIVE sealant. As far as I know Lifecaulk does not make an adhesive sealant and is basically a polysulfide crack filler. What's the theory behind using Lifecaulk versus an adhesive sealant?



TomCambria@mindspring.com

[John R.]

I spoke with Canada Metal today and was given the complete run down on the Martyr prop zinc anode sold by West Marine.

Basically it is a very similar design to the Electro-Guard and as such is also vulnerable to the zinc shell retaining screw coming loose due to decomposition of the zinc. They recognize this anomaly and deal with this potential problem by using what they term a "nylon patch hex fastener". What that means is they have the fastener threads coated with nylon which basically acts like a nyloc hex nut and won't vibrate loose. The caveat though is that there is nothing to prevent the zinc from decomposing under the fastener head. The same design problem exists with the Electro-Guard from discussions I've had with people today that have and do use them.

Canada metal advises that the end of the zinc (area under the fastener head) be painted with a couple of coats of bottom paint. They say their experience and lab tests have shown that it keeps the zinc from decomposing in that area from the insulation afforded by the paint. In theory it sounds reasonable except when one considers the copper content of the paint in contact with the zinc surface and the fastener.

It seems to me that both the Martyr and the Electro-Guard are equally prone to the same potential pitfall of possibly coming loose because of the same reason. The good news is that at least the zinc replacement sleeve is relatively cheap when compared to the cost of an entire Perry Nut when they were available. The Perry Nut was problem free however.

The advantage of the Martyr over the E-G is that because of the nylon coated fastener the zinc sleeve can be replaced under water and yet still be secure. Where with the E-G you need to use a loctite, caulk or similar on the fastener threads to keep it secured which can't be used under water if the zinc sleeve needs changing between haulouts.

The downside to the Martyr is that it uses a black mild steel fastener instead of stainless to secure the zinc sleeve in position. That means it will oxidize (rust) when the boat is out of the water. It is fine if it is kept underwater and protected by the zinc that it retains in position. I was told they are in the process of changing that fastener to stainless but the general public will not see that version for about 8 months unless it is special ordered. Of course the fastener can just be replaced with a stainless one but it won't have the nylon coating on the threads to secure it.

They said that all zinc replacement sleeves will be furnished with a new nylon coated fastener. Once these fasteners are installed and then removed they should be discarded as the nylon coating on the threads obviously will no longer be effective.

Hope this info is of help for anyone seeking a substitution for the good old Perry Nut.

John, Thanks for the info. Doesn't painting the end of the zinc create an insulator between the zinc and prop shaft? If you are of the school that believes the star washer was used to insure good contact between the zinc, the bolt and the prop shaft, then you are defeating the whole reason for the star washer (and interrupting the continuity). Unless you believe that the copper in the bottom paint provides enough continuity to pass a week electric current. I'd be skeptical about this until proven to me.

I'd be inclined to go with a ss bolt replacement unless they're using a non-standard thread. BTW 5200 does set underwater and can be used underwater - the directions even say you can spray it with water to speed curing. However it IS a lot of fuss. On the other hand the last diver I hired to change my EG zinc in the water crossthreaded the bronze nut and couldn't tighten the bolt up against the star washer or the zinc. I found out at the next haulout that the zinc was slammming around down there with a quarter inch of play. A friend of mine hired a diver to do his zinc and the diver told him he had dropped the bolt so couldn't put the zinc on, but he'd get another bolt and come back and do it. He later told him he had, but at haulout he discovered the diver hadn't and he'd been without a zinc for at leat four months. Changing zincs in the water is a tricky business at best with the electro guard system. Maybe in real clear, warm water, but in most marinas it's a last choice for me.

I'd plan to do it at haulout where you can stand comfortably with perfect vision and pick it up if you drop it. Thus the question of how hard it would be to do in the water I don't think should be factored into one's reasoning. I think we should think in terms of what's best just assuming it can be done right. If you drop your plastic tipped bolt, you're going to play hell getting one at the local chandlery too. The question is, are you even going to be able to get Electro Guard zincs if the retailers switch to something else? Perhaps EG will go the way of the Perry Nut.

Final thought - MILD steel? Bronze and Stainless are fairly close on the galvanic scale. Bronze and mild steel are not close on the galvanic scale. Sure, it might not rust underwater if not exposed to air, but how about the galvanic potential? If your bronze prop and stainless shaft eat that rust free mild steel bolt, the plastic tips that are left won't hold your zinc on. Some of you metallurical wizards straighten me out on this. Is it OK to put mild steel up against bronze under salt water?

Tom,I would think that even if a person was to take their advice and place a very small amount of bottom paint on the end of the zinc sleeve just under the fastener head that it wouldn't compromise electrical contact to any great degree because so much of the inside of the zinc sleeve contacts the bronze core. I'm sure it compromises contact somewhat but who knows how much? They say they have been doing it for years and they did say they ran plenty of tests before recommending it.

I finally got to look at a Martyr prop nut zinc unit yesterday at West Marine in Ft. Lauderdale. They had one with a mild black steel socket screw fastener and another with the stainless fastener version. Neither has any type of lock washer and Canada Metal never said they come with one. The fasteners were coated with a very thin layer of the nylon that they had described. The threads are SAE thread, nothing special except for the nylon coating. It seems after looking at the units that there is plenty of zinc to bronze contact. Only thing that concerns me is since I've never used one of these style zincs other than Perry's I don't know if much decomposition of the zinc sleeve occurs on the inside. Maybe someone can elaborate on that point.

Apparently if that 5200 is applicable under water then there is no reason the zinc can't be serviced over and over again by a quality diver. It wouldn't take just a dab on the threads to secure the fastener. I would wonder about the ease of removal however. If I decide to use these zincs I would probably go with the bottom paint under the fastener head and use a stainless fastener with flat washer and lock washer.

I guess a $40 experiment isn't all too expensive. If the zinc sleeve comes loose or falls off I'll try something else. Maybe at next haulout I'll take a closer look at possibly fitting a collar zinc in front of the prop.

BTW, virtually all my prop zincs are changed by a diver because our haulouts every couple years not like up north where its every 6 or 8 months. A big difference. I'm not about to pay haulout fees to replace a little zinc.

About that galvanic difference betweeen the mild steel and the bronze, that's why the zinc is there. I know, I'm thinking the same thing, it will just degrade the zinc that much faster. Not a problem says Canada Metal, based on their tests. But! Because of the perceived problem by the general public that is why they are switching to the stainless. They said the only difference it is going to make is to drive the cost up.

It's too bad the zinc sleeve itself doesn't screw onto the bronze core. The ones for the Beneateu are made that way. They are really nice zincs, hefty and solid like a Perry. I don't know how they keep the bronze piece locked onto the shaft based on the quick look I gave them. Also the complete units are pricey little suckers.

Let's face it......Perry Nuts are where it's at. Send letters, make phone calls and who knows maybe there's a chance they will start to produce them again.

[Tom]

I spoke with Canada Metal today and was given the complete run down on the Martyr prop zinc anode sold by West Marine.

Basically it is a very similar design to the Electro-Guard and as such is also vulnerable to the zinc shell retaining screw coming loose due to decomposition of the zinc. They recognize this anomaly and deal with this potential problem by using what they term a "nylon patch hex fastener". What that means is they have the fastener threads coated with nylon which basically acts like a nyloc hex nut and won't vibrate loose. The caveat though is that there is nothing to prevent the zinc from decomposing under the fastener head. The same design problem exists with the Electro-Guard from discussions I've had with people today that have and do use them.

Canada metal advises that the end of the zinc (area under the fastener head) be painted with a couple of coats of bottom paint. They say their experience and lab tests have shown that it keeps the zinc from decomposing in that area from the insulation afforded by the paint. In theory it sounds reasonable except when one considers the copper content of the paint in contact with the zinc surface and the fastener.

It seems to me that both the Martyr and the Electro-Guard are equally prone to the same potential pitfall of possibly coming loose because of the same reason. The good news is that at least the zinc replacement sleeve is relatively cheap when compared to the cost of an entire Perry Nut when they were available. The Perry Nut was problem free however.

The advantage of the Martyr over the E-G is that because of the nylon coated fastener the zinc sleeve can be replaced under water and yet still be secure. Where with the E-G you need to use a loctite, caulk or similar on the fastener threads to keep it secured which can't be used under water if the zinc sleeve needs changing between haulouts.

The downside to the Martyr is that it uses a black mild steel fastener instead of stainless to secure the zinc sleeve in position. That means it will oxidize (rust) when the boat is out of the water. It is fine if it is kept underwater and protected by the zinc that it retains in position. I was told they are in the process of changing that fastener to stainless but the general public will not see that version for about 8 months unless it is special ordered. Of course the fastener can just be replaced with a stainless one but it won't have the nylon coating on the threads to secure it.

They said that all zinc replacement sleeves will be furnished with a new nylon coated fastener. Once these fasteners are installed and then removed they should be discarded as the nylon coating on the threads obviously will no longer be effective.

Hope this info is of help for anyone seeking a substitution for the good old Perry Nut.

John, Thanks for the info. Doesn't painting the end of the zinc create an insulator between the zinc and prop shaft? If you are of the school that believes the star washer was used to insure good contact between the zinc, the bolt and the prop shaft, then you are defeating the whole reason for the star washer (and interrupting the continuity). Unless you believe that the copper in the bottom paint provides enough continuity to pass a week electric current. I'd be skeptical about this until proven to me.

I'd be inclined to go with a ss bolt replacement unless they're using a non-standard thread. BTW 5200 does set underwater and can be used underwater - the directions even say you can spray it with water to speed curing. However it IS a lot of fuss. On the other hand the last diver I hired to change my EG zinc in the water crossthreaded the bronze nut and couldn't tighten the bolt up against the star washer or the zinc. I found out at the next haulout that the zinc was slammming around down there with a quarter inch of play. A friend of mine hired a diver to do his zinc and the diver told him he had dropped the bolt so couldn't put the zinc on, but he'd get another bolt and come back and do it. He later told him he had, but at haulout he discovered the diver hadn't and he'd been without a zinc for at leat four months. Changing zincs in the water is a tricky business at best with the electro guard system. Maybe in real clear, warm water, but in most marinas it's a last choice for me.

I'd plan to do it at haulout where you can stand comfortably with perfect vision and pick it up if you drop it. Thus the question of how hard it would be to do in the water I don't think should be factored into one's reasoning. I think we should think in terms of what's best just assuming it can be done right. If you drop your plastic tipped bolt, you're going to play hell getting one at the local chandlery too. The question is, are you even going to be able to get Electro Guard zincs if the retailers switch to something else? Perhaps EG will go the way of the Perry Nut.

Final thought - MILD steel? Bronze and Stainless are fairly close on the galvanic scale. Bronze and mild steel are not close on the galvanic scale. Sure, it might not rust underwater if not exposed to air, but how about the galvanic potential? If your bronze prop and stainless shaft eat that rust free mild steel bolt, the plastic tips that are left won't hold your zinc on. Some of you metallurical wizards straighten me out on this. Is it OK to put mild steel up against bronze under salt water?

Tom,I would think that even if a person was to take their advice and place a very small amount of bottom paint on the end of the zinc sleeve just under the fastener head that it wouldn't compromise electrical contact to any great degree because so much of the inside of the zinc sleeve contacts the bronze core. I'm sure it compromises contact somewhat but who knows how much? They say they have been doing it for years and they did say they ran plenty of tests before recommending it.

I finally got to look at a Martyr prop nut zinc unit yesterday at West Marine in Ft. Lauderdale. They had one with a mild black steel socket screw fastener and another with the stainless fastener version. Neither has any type of lock washer and Canada Metal never said they come with one. The fasteners were coated with a very thin layer of the nylon that they had described. The threads are SAE thread, nothing special except for the nylon coating. It seems after looking at the units that there is plenty of zinc to bronze contact. Only thing that concerns me is since I've never used one of these style zincs other than Perry's I don't know if much decomposition of the zinc sleeve occurs on the inside. Maybe someone can elaborate on that point.

Apparently if that 5200 is applicable under water then there is no reason the zinc can't be serviced over and over again by a quality diver. It wouldn't take just a dab on the threads to secure the fastener. I would wonder about the ease of removal however. If I decide to use these zincs I would probably go with the bottom paint under the fastener head and use a stainless fastener with flat washer and lock washer.

I guess a $40 experiment isn't all too expensive. If the zinc sleeve comes loose or falls off I'll try something else. Maybe at next haulout I'll take a closer look at possibly fitting a collar zinc in front of the prop.

BTW, virtually all my prop zincs are changed by a diver because our haulouts every couple years not like up north where its every 6 or 8 months. A big difference. I'm not about to pay haulout fees to replace a little zinc.

About that galvanic difference betweeen the mild steel and the bronze, that's why the zinc is there. I know, I'm thinking the same thing, it will just degrade the zinc that much faster. Not a problem says Canada Metal, based on their tests. But! Because of the perceived problem by the general public that is why they are switching to the stainless. They said the only difference it is going to make is to drive the cost up.

It's too bad the zinc sleeve itself doesn't screw onto the bronze core. The ones for the Beneateu are made that way. They are really nice zincs, hefty and solid like a Perry. I don't know how they keep the bronze piece locked onto the shaft based on the quick look I gave them. Also the complete units are pricey little suckers.

Let's face it......Perry Nuts are where it's at. Send letters, make phone calls and who knows maybe there's a chance they will start to produce them again.

As far as Perry going into production again these companies usually stop not on just some whim, but because an environmental agency has declared them as a producer that is polluting. There used to be a lot of shops around that would re-galvanize your chain for you, but when you melt zinc it puts off toxic fumes. Or so they tell us here in Calif. Little guys don't have the kind of bucks that it takes to put in the filters and scrubbers and whatever to meet the environmental laws, plus they have to weigh the benefits of producing some little item against the hassle involved from some govt. agency. Several hundred Cape Dory owners pounding on them probably isn't going to change that basic equation. I don't know anything about the Perry Boatyard so this is just speculation on my part. It would be nice if Northill would start making forged Northill anchors again too. In my experience probably the best anchor ever designed and the one that Jacques Costeau used on Calypso if you remember.

In answer to your question about where zincs corrode. Mine always seem to dissolve from the outside in and thus the interior remains in pretty good shape. I always thought that the bonding between the zinc and the bronze was along the interior of the zinc, but when I posted that on this board several people raised a question about that and pointed out that a "star" type lock washer has a special purpose and there may be a reason not to use a standard split ring type lock washer. I don't know the answer to that, but a stainless star lock washer is not an easy item to find so there well may be a reason that Electro Guard goes to the trouble to provide that with their replaceable zincs.

If you want to isolate the zinc from the bolt, why not just provide a nylon or plastic washer to go between there? Painting your zinc with bottom paint seems like a ham fisted design to come up with. If you've got a nylon coated bolt that won't unscrew and thus you don't need a lock washer, why not a plastic washer that is cheap, readily available, and positive? Actually if Martyr is selling these bolts separately, why not just buy the bolt and use it with your Electro Guard replacement zinc? That would eliminate the need for 5200 and a lock washer on the Electro Guard zinc -- which seems to be the only rap against them.

Don't get me wrong, I don't have anything against the Martyr nut. I've never even seen one. We may all be going to them in the future if Boat US and West are going to stop carrying EG nuts. I just wonder about a company that comes on the market with a new nut and tells you that to fix the design flaw they've designed into it, you have to paint your zinc with bottom paint. Doesn't this make you wonder?

Thanks for generating all this discussion. Cape Dory owners who read this board are going to know more than anyone about the new Martyr nuts. If Martyr sells their stainless nylon coated bolts separately, how about posting their address or phone # here. I'm willing to try one and see how it works with my EG zinc this year.



TomCambria@mindspring.com

[John R.]

John, Thanks for the info. Doesn't painting the end of the zinc create an insulator between the zinc and prop shaft? If you are of the school that believes the star washer was used to insure good contact between the zinc, the bolt and the prop shaft, then you are defeating the whole reason for the star washer (and interrupting the continuity). Unless you believe that the copper in the bottom paint provides enough continuity to pass a week electric current. I'd be skeptical about this until proven to me.

I'd be inclined to go with a ss bolt replacement unless they're using a non-standard thread. BTW 5200 does set underwater and can be used underwater - the directions even say you can spray it with water to speed curing. However it IS a lot of fuss. On the other hand the last diver I hired to change my EG zinc in the water crossthreaded the bronze nut and couldn't tighten the bolt up against the star washer or the zinc. I found out at the next haulout that the zinc was slammming around down there with a quarter inch of play. A friend of mine hired a diver to do his zinc and the diver told him he had dropped the bolt so couldn't put the zinc on, but he'd get another bolt and come back and do it. He later told him he had, but at haulout he discovered the diver hadn't and he'd been without a zinc for at leat four months. Changing zincs in the water is a tricky business at best with the electro guard system. Maybe in real clear, warm water, but in most marinas it's a last choice for me.

I'd plan to do it at haulout where you can stand comfortably with perfect vision and pick it up if you drop it. Thus the question of how hard it would be to do in the water I don't think should be factored into one's reasoning. I think we should think in terms of what's best just assuming it can be done right. If you drop your plastic tipped bolt, you're going to play hell getting one at the local chandlery too. The question is, are you even going to be able to get Electro Guard zincs if the retailers switch to something else? Perhaps EG will go the way of the Perry Nut.

Final thought - MILD steel? Bronze and Stainless are fairly close on the galvanic scale. Bronze and mild steel are not close on the galvanic scale. Sure, it might not rust underwater if not exposed to air, but how about the galvanic potential? If your bronze prop and stainless shaft eat that rust free mild steel bolt, the plastic tips that are left won't hold your zinc on. Some of you metallurical wizards straighten me out on this. Is it OK to put mild steel up against bronze under salt water?

Tom,I would think that even if a person was to take their advice and place a very small amount of bottom paint on the end of the zinc sleeve just under the fastener head that it wouldn't compromise electrical contact to any great degree because so much of the inside of the zinc sleeve contacts the bronze core. I'm sure it compromises contact somewhat but who knows how much? They say they have been doing it for years and they did say they ran plenty of tests before recommending it.

I finally got to look at a Martyr prop nut zinc unit yesterday at West Marine in Ft. Lauderdale. They had one with a mild black steel socket screw fastener and another with the stainless fastener version. Neither has any type of lock washer and Canada Metal never said they come with one. The fasteners were coated with a very thin layer of the nylon that they had described. The threads are SAE thread, nothing special except for the nylon coating. It seems after looking at the units that there is plenty of zinc to bronze contact. Only thing that concerns me is since I've never used one of these style zincs other than Perry's I don't know if much decomposition of the zinc sleeve occurs on the inside. Maybe someone can elaborate on that point.

Apparently if that 5200 is applicable under water then there is no reason the zinc can't be serviced over and over again by a quality diver. It wouldn't take just a dab on the threads to secure the fastener. I would wonder about the ease of removal however. If I decide to use these zincs I would probably go with the bottom paint under the fastener head and use a stainless fastener with flat washer and lock washer.

I guess a $40 experiment isn't all too expensive. If the zinc sleeve comes loose or falls off I'll try something else. Maybe at next haulout I'll take a closer look at possibly fitting a collar zinc in front of the prop.

BTW, virtually all my prop zincs are changed by a diver because our haulouts every couple years not like up north where its every 6 or 8 months. A big difference. I'm not about to pay haulout fees to replace a little zinc.

About that galvanic difference betweeen the mild steel and the bronze, that's why the zinc is there. I know, I'm thinking the same thing, it will just degrade the zinc that much faster. Not a problem says Canada Metal, based on their tests. But! Because of the perceived problem by the general public that is why they are switching to the stainless. They said the only difference it is going to make is to drive the cost up.

It's too bad the zinc sleeve itself doesn't screw onto the bronze core. The ones for the Beneateu are made that way. They are really nice zincs, hefty and solid like a Perry. I don't know how they keep the bronze piece locked onto the shaft based on the quick look I gave them. Also the complete units are pricey little suckers.

Let's face it......Perry Nuts are where it's at. Send letters, make phone calls and who knows maybe there's a chance they will start to produce them again.

As far as Perry going into production again these companies usually stop not on just some whim, but because an environmental agency has declared them as a producer that is polluting. There used to be a lot of shops around that would re-galvanize your chain for you, but when you melt zinc it puts off toxic fumes. Or so they tell us here in Calif. Little guys don't have the kind of bucks that it takes to put in the filters and scrubbers and whatever to meet the environmental laws, plus they have to weigh the benefits of producing some little item against the hassle involved from some govt. agency. Several hundred Cape Dory owners pounding on them probably isn't going to change that basic equation. I don't know anything about the Perry Boatyard so this is just speculation on my part. It would be nice if Northill would start making forged Northill anchors again too. In my experience probably the best anchor ever designed and the one that Jacques Costeau used on Calypso if you remember.

In answer to your question about where zincs corrode. Mine always seem to dissolve from the outside in and thus the interior remains in pretty good shape. I always thought that the bonding between the zinc and the bronze was along the interior of the zinc, but when I posted that on this board several people raised a question about that and pointed out that a "star" type lock washer has a special purpose and there may be a reason not to use a standard split ring type lock washer. I don't know the answer to that, but a stainless star lock washer is not an easy item to find so there well may be a reason that Electro Guard goes to the trouble to provide that with their replaceable zincs.

If you want to isolate the zinc from the bolt, why not just provide a nylon or plastic washer to go between there? Painting your zinc with bottom paint seems like a ham fisted design to come up with. If you've got a nylon coated bolt that won't unscrew and thus you don't need a lock washer, why not a plastic washer that is cheap, readily available, and positive? Actually if Martyr is selling these bolts separately, why not just buy the bolt and use it with your Electro Guard replacement zinc? That would eliminate the need for 5200 and a lock washer on the Electro Guard zinc -- which seems to be the only rap against them.

Don't get me wrong, I don't have anything against the Martyr nut. I've never even seen one. We may all be going to them in the future if Boat US and West are going to stop carrying EG nuts. I just wonder about a company that comes on the market with a new nut and tells you that to fix the design flaw they've designed into it, you have to paint your zinc with bottom paint. Doesn't this make you wonder?

Thanks for generating all this discussion. Cape Dory owners who read this board are going to know more than anyone about the new Martyr nuts. If Martyr sells their stainless nylon coated bolts separately, how about posting their address or phone # here. I'm willing to try one and see how it works with my EG zinc this year.

Tom,
Let me clarify one point in your remarks. I do not have nor ever have had an Electro-Guard propnut zinc on my CD. I don't think in my other posts that I ever said I did. However, I know some people that have been using them. I've only used Perry Nuts on my CD, but I only have a few left and am looking for a future replacement.

The Martyr zinc is not new. It has been made by Canada Metal for several years according to them. You pose a lot of questions that I think you best confront Canada Metal with. I am not an advocate for Canada Metal nor Electro-Guard. I'm simply trying to make a reasonable comparison of the two zincs which are quite similar in the hope of trying to determine which would be the best choice as a replacement for the Perry Nut. I know there are many of us faced with the situation of having to make a choice as to what replacement we will use for the Perry. After consulting catalogs and local chandlers and speaking with friends in the business it seems the Martyr or Camp is the easiest to obtain.

West Marine only has the Electro-Guard propnut zinc on their website, it is not in their catalog nor in any of their stores around here (Florida). The Martyr is on their website in a lot more sizes than E-G and is stocked in their stores. Boat U.S. carries neither brand. They carry Marshall zincs and they don't stock a propnut zinc.

Camp zincs makes a real nice compact propnut zinc. It locks into place by a castellated prop nut and is from my observations the way to go. It is cheaper than the Canada and Electro-Guard zincs. It is not available off the shelf from Boat U.S. or West. Maybe it can be special ordered from them, I do not know as I haven't checked into that. It is available from most regular marine distributors. Check with your local marine store and look in their distributors catalog. It comes in many sizes.

I don't know anything about enviromental zinc processing laws, I'm sure they are strict. California of course has far tighter regulations than anywhere else, almost another country in some respects.

I do know that smelting regulations are NOT the reason Perry Nuts are not being produced. In an earlier post on this board I informed everyone that the people at Perry's told me via a phone call that the molds for the nuts were lost by the company that produced the nuts for Perry. The producer went bankrupt and the molds were lost. That is what Perry told me. They also said to let them know if there was a market for the nuts.

I highly doubt that the star washer provided by E-G has anything to do with an attempt to engineer in better current flow into their zinc from the metals of the prop and shaft. The stainless washer and fastener would be a terrible electrical conductor material to use between the zinc sleeve and the bronze core, especially considering the extremely low current that would exist. The small contact surface area would even add to the problem. A bronze star washer and fastener would be far more appropriate to conduct current. My question in the last post about the contact area between the inside of the zinc sleeve and the core was very important for that exact reason. You answered with what I'd hoped to hear, that the inside of your zinc sleeve looked very intact. My assumption is that the star washer is strictly there to perform as a locking mechanism. Evidently it hasn't performed that well for some as they have come loose and even been lost by some users. We don't know that the nylon coated fastener used in the Martyr performs any better.

I believe I already posted contact info for Canada Metal in an earlier post. If you can't find it give West Marine a call and ask them to connect you with technical info on Canada Metal zincs, they'll connect you to the company.

[Tom]

John,

If I've made you feel defensive, please let me apologize. I certainly didn't mean to sound like I was challenging you. The thread you initiated has brought extremely valuable information to all of us. I didn't know about this board the first time I changed my zincs and nobody in this area had the original Perry nut. Everybody was carrying Electro Guard at that time so that is what I switched to and have been using for the last 12 yers or so. I have never particularly liked it because of the size although I did like the feature that enabled you to switch just the zinc. I was one of the people who had the bolt unscrew underway and had the prop wash fire the zinc back into the rudder leaving a nice divot in the rudder. I didn't like that. Since putting 5200 on the bolt that hasn't happened again, but maybe I've just been lucky. In any case I think it's a questionable design when you have to put 5200 on it as designed to make it work. Since Wierd Marine and Bats US have stopped carrying Electro Guard we're all up against it. So far the local chandlery still carries the EG zincs, but this may just be until their stock runs out. The reason I was questioning you so particularly was that you had the real dope on the Martyr design. You've done a real service for all of us. Thanks again.

Tom,I would think that even if a person was to take their advice and place a very small amount of bottom paint on the end of the zinc sleeve just under the fastener head that it wouldn't compromise electrical contact to any great degree because so much of the inside of the zinc sleeve contacts the bronze core. I'm sure it compromises contact somewhat but who knows how much? They say they have been doing it for years and they did say they ran plenty of tests before recommending it.

I finally got to look at a Martyr prop nut zinc unit yesterday at West Marine in Ft. Lauderdale. They had one with a mild black steel socket screw fastener and another with the stainless fastener version. Neither has any type of lock washer and Canada Metal never said they come with one. The fasteners were coated with a very thin layer of the nylon that they had described. The threads are SAE thread, nothing special except for the nylon coating. It seems after looking at the units that there is plenty of zinc to bronze contact. Only thing that concerns me is since I've never used one of these style zincs other than Perry's I don't know if much decomposition of the zinc sleeve occurs on the inside. Maybe someone can elaborate on that point.

Apparently if that 5200 is applicable under water then there is no reason the zinc can't be serviced over and over again by a quality diver. It wouldn't take just a dab on the threads to secure the fastener. I would wonder about the ease of removal however. If I decide to use these zincs I would probably go with the bottom paint under the fastener head and use a stainless fastener with flat washer and lock washer.

I guess a $40 experiment isn't all too expensive. If the zinc sleeve comes loose or falls off I'll try something else. Maybe at next haulout I'll take a closer look at possibly fitting a collar zinc in front of the prop.

BTW, virtually all my prop zincs are changed by a diver because our haulouts every couple years not like up north where its every 6 or 8 months. A big difference. I'm not about to pay haulout fees to replace a little zinc.

About that galvanic difference betweeen the mild steel and the bronze, that's why the zinc is there. I know, I'm thinking the same thing, it will just degrade the zinc that much faster. Not a problem says Canada Metal, based on their tests. But! Because of the perceived problem by the general public that is why they are switching to the stainless. They said the only difference it is going to make is to drive the cost up.

It's too bad the zinc sleeve itself doesn't screw onto the bronze core. The ones for the Beneateu are made that way. They are really nice zincs, hefty and solid like a Perry. I don't know how they keep the bronze piece locked onto the shaft based on the quick look I gave them. Also the complete units are pricey little suckers.

Let's face it......Perry Nuts are where it's at. Send letters, make phone calls and who knows maybe there's a chance they will start to produce them again.

As far as Perry going into production again these companies usually stop not on just some whim, but because an environmental agency has declared them as a producer that is polluting. There used to be a lot of shops around that would re-galvanize your chain for you, but when you melt zinc it puts off toxic fumes. Or so they tell us here in Calif. Little guys don't have the kind of bucks that it takes to put in the filters and scrubbers and whatever to meet the environmental laws, plus they have to weigh the benefits of producing some little item against the hassle involved from some govt. agency. Several hundred Cape Dory owners pounding on them probably isn't going to change that basic equation. I don't know anything about the Perry Boatyard so this is just speculation on my part. It would be nice if Northill would start making forged Northill anchors again too. In my experience probably the best anchor ever designed and the one that Jacques Costeau used on Calypso if you remember.

In answer to your question about where zincs corrode. Mine always seem to dissolve from the outside in and thus the interior remains in pretty good shape. I always thought that the bonding between the zinc and the bronze was along the interior of the zinc, but when I posted that on this board several people raised a question about that and pointed out that a "star" type lock washer has a special purpose and there may be a reason not to use a standard split ring type lock washer. I don't know the answer to that, but a stainless star lock washer is not an easy item to find so there well may be a reason that Electro Guard goes to the trouble to provide that with their replaceable zincs.

If you want to isolate the zinc from the bolt, why not just provide a nylon or plastic washer to go between there? Painting your zinc with bottom paint seems like a ham fisted design to come up with. If you've got a nylon coated bolt that won't unscrew and thus you don't need a lock washer, why not a plastic washer that is cheap, readily available, and positive? Actually if Martyr is selling these bolts separately, why not just buy the bolt and use it with your Electro Guard replacement zinc? That would eliminate the need for 5200 and a lock washer on the Electro Guard zinc -- which seems to be the only rap against them.

Don't get me wrong, I don't have anything against the Martyr nut. I've never even seen one. We may all be going to them in the future if Boat US and West are going to stop carrying EG nuts. I just wonder about a company that comes on the market with a new nut and tells you that to fix the design flaw they've designed into it, you have to paint your zinc with bottom paint. Doesn't this make you wonder?

Thanks for generating all this discussion. Cape Dory owners who read this board are going to know more than anyone about the new Martyr nuts. If Martyr sells their stainless nylon coated bolts separately, how about posting their address or phone # here. I'm willing to try one and see how it works with my EG zinc this year.

Tom,
Let me clarify one point in your remarks. I do not have nor ever have had an Electro-Guard propnut zinc on my CD. I don't think in my other posts that I ever said I did. However, I know some people that have been using them. I've only used Perry Nuts on my CD, but I only have a few left and am looking for a future replacement.

The Martyr zinc is not new. It has been made by Canada Metal for several years according to them. You pose a lot of questions that I think you best confront Canada Metal with. I am not an advocate for Canada Metal nor Electro-Guard. I'm simply trying to make a reasonable comparison of the two zincs which are quite similar in the hope of trying to determine which would be the best choice as a replacement for the Perry Nut. I know there are many of us faced with the situation of having to make a choice as to what replacement we will use for the Perry. After consulting catalogs and local chandlers and speaking with friends in the business it seems the Martyr or Camp is the easiest to obtain.

West Marine only has the Electro-Guard propnut zinc on their website, it is not in their catalog nor in any of their stores around here (Florida). The Martyr is on their website in a lot more sizes than E-G and is stocked in their stores. Boat U.S. carries neither brand. They carry Marshall zincs and they don't stock a propnut zinc.

Camp zincs makes a real nice compact propnut zinc. It locks into place by a castellated prop nut and is from my observations the way to go. It is cheaper than the Canada and Electro-Guard zincs. It is not available off the shelf from Boat U.S. or West. Maybe it can be special ordered from them, I do not know as I haven't checked into that. It is available from most regular marine distributors. Check with your local marine store and look in their distributors catalog. It comes in many sizes.

I don't know anything about enviromental zinc processing laws, I'm sure they are strict. California of course has far tighter regulations than anywhere else, almost another country in some respects.

I do know that smelting regulations are NOT the reason Perry Nuts are not being produced. In an earlier post on this board I informed everyone that the people at Perry's told me via a phone call that the molds for the nuts were lost by the company that produced the nuts for Perry. The producer went bankrupt and the molds were lost. That is what Perry told me. They also said to let them know if there was a market for the nuts.

I highly doubt that the star washer provided by E-G has anything to do with an attempt to engineer in better current flow into their zinc from the metals of the prop and shaft. The stainless washer and fastener would be a terrible electrical conductor material to use between the zinc sleeve and the bronze core, especially considering the extremely low current that would exist. The small contact surface area would even add to the problem. A bronze star washer and fastener would be far more appropriate to conduct current. My question in the last post about the contact area between the inside of the zinc sleeve and the core was very important for that exact reason. You answered with what I'd hoped to hear, that the inside of your zinc sleeve looked very intact. My assumption is that the star washer is strictly there to perform as a locking mechanism. Evidently it hasn't performed that well for some as they have come loose and even been lost by some users. We don't know that the nylon coated fastener used in the Martyr performs any better.

I believe I already posted contact info for Canada Metal in an earlier post. If you can't find it give West Marine a call and ask them to connect you with technical info on Canada Metal zincs, they'll connect you to the company.

TomCambria@mindspring.com

[John R.]

Tom,

Hey no problem at all. I didn't mean to sound defensive. I was only attempting to make some details clear for folks that may have read our posts. I like you and I'm sure like many others are getting concerned about the prop zinc dilemma and are looking for the best alternative to the Perry at a cost that is reasonable and with product performance that is good.

It takes good detailed discussion of all the aspects of these components to determine the optimum part. I believe that is what this board is all about. I think the last few postings between us have been good and very informative and wish others had participated and brought forth their detailed experiences with various zincs under discussion and introduced others that have not been discussed.

If you get a chance look into the Camp propnut zinc. I'm going to order one for the 1" shaft. I have an extra shaft in my garage and will take a picture of the components and also a picture of the unit installed on the shaft. Then I'll post a message about it and if someone wants to see it I'll send them an e-mail pic.

I totally agree with you that there is something questionable about the design of the E-G and CM Martyr anodes. The caulk, the bottom paint, the nylon coating........ to me all that stuff means poor design. I liked the dependable cotter in the Perry Nuts, they worked.

Thanks for the detailed info on your experienced use of the E-G zincs.

John,

If I've made you feel defensive, please let me apologize. I certainly didn't mean to sound like I was challenging you. The thread you initiated has brought extremely valuable information to all of us. I didn't know about this board the first time I changed my zincs and nobody in this area had the original Perry nut. Everybody was carrying Electro Guard at that time so that is what I switched to and have been using for the last 12 yers or so. I have never particularly liked it because of the size although I did like the feature that enabled you to switch just the zinc. I was one of the people who had the bolt unscrew underway and had the prop wash fire the zinc back into the rudder leaving a nice divot in the rudder. I didn't like that. Since putting 5200 on the bolt that hasn't happened again, but maybe I've just been lucky. In any case I think it's a questionable design when you have to put 5200 on it as designed to make it work. Since Wierd Marine and Bats US have stopped carrying Electro Guard we're all up against it. So far the local chandlery still carries the EG zincs, but this may just be until their stock runs out. The reason I was questioning you so particularly was that you had the real dope on the Martyr design. You've done a real service for all of us. Thanks again.

As far as Perry going into production again these companies usually stop not on just some whim, but because an environmental agency has declared them as a producer that is polluting. There used to be a lot of shops around that would re-galvanize your chain for you, but when you melt zinc it puts off toxic fumes. Or so they tell us here in Calif. Little guys don't have the kind of bucks that it takes to put in the filters and scrubbers and whatever to meet the environmental laws, plus they have to weigh the benefits of producing some little item against the hassle involved from some govt. agency. Several hundred Cape Dory owners pounding on them probably isn't going to change that basic equation. I don't know anything about the Perry Boatyard so this is just speculation on my part. It would be nice if Northill would start making forged Northill anchors again too. In my experience probably the best anchor ever designed and the one that Jacques Costeau used on Calypso if you remember.

In answer to your question about where zincs corrode. Mine always seem to dissolve from the outside in and thus the interior remains in pretty good shape. I always thought that the bonding between the zinc and the bronze was along the interior of the zinc, but when I posted that on this board several people raised a question about that and pointed out that a "star" type lock washer has a special purpose and there may be a reason not to use a standard split ring type lock washer. I don't know the answer to that, but a stainless star lock washer is not an easy item to find so there well may be a reason that Electro Guard goes to the trouble to provide that with their replaceable zincs.

If you want to isolate the zinc from the bolt, why not just provide a nylon or plastic washer to go between there? Painting your zinc with bottom paint seems like a ham fisted design to come up with. If you've got a nylon coated bolt that won't unscrew and thus you don't need a lock washer, why not a plastic washer that is cheap, readily available, and positive? Actually if Martyr is selling these bolts separately, why not just buy the bolt and use it with your Electro Guard replacement zinc? That would eliminate the need for 5200 and a lock washer on the Electro Guard zinc -- which seems to be the only rap against them.

Don't get me wrong, I don't have anything against the Martyr nut. I've never even seen one. We may all be going to them in the future if Boat US and West are going to stop carrying EG nuts. I just wonder about a company that comes on the market with a new nut and tells you that to fix the design flaw they've designed into it, you have to paint your zinc with bottom paint. Doesn't this make you wonder?

Thanks for generating all this discussion. Cape Dory owners who read this board are going to know more than anyone about the new Martyr nuts. If Martyr sells their stainless nylon coated bolts separately, how about posting their address or phone # here. I'm willing to try one and see how it works with my EG zinc this year.

Tom,
Let me clarify one point in your remarks. I do not have nor ever have had an Electro-Guard propnut zinc on my CD. I don't think in my other posts that I ever said I did. However, I know some people that have been using them. I've only used Perry Nuts on my CD, but I only have a few left and am looking for a future replacement.

The Martyr zinc is not new. It has been made by Canada Metal for several years according to them. You pose a lot of questions that I think you best confront Canada Metal with. I am not an advocate for Canada Metal nor Electro-Guard. I'm simply trying to make a reasonable comparison of the two zincs which are quite similar in the hope of trying to determine which would be the best choice as a replacement for the Perry Nut. I know there are many of us faced with the situation of having to make a choice as to what replacement we will use for the Perry. After consulting catalogs and local chandlers and speaking with friends in the business it seems the Martyr or Camp is the easiest to obtain.

West Marine only has the Electro-Guard propnut zinc on their website, it is not in their catalog nor in any of their stores around here (Florida). The Martyr is on their website in a lot more sizes than E-G and is stocked in their stores. Boat U.S. carries neither brand. They carry Marshall zincs and they don't stock a propnut zinc.

Camp zincs makes a real nice compact propnut zinc. It locks into place by a castellated prop nut and is from my observations the way to go. It is cheaper than the Canada and Electro-Guard zincs. It is not available off the shelf from Boat U.S. or West. Maybe it can be special ordered from them, I do not know as I haven't checked into that. It is available from most regular marine distributors. Check with your local marine store and look in their distributors catalog. It comes in many sizes.

I don't know anything about enviromental zinc processing laws, I'm sure they are strict. California of course has far tighter regulations than anywhere else, almost another country in some respects.

I do know that smelting regulations are NOT the reason Perry Nuts are not being produced. In an earlier post on this board I informed everyone that the people at Perry's told me via a phone call that the molds for the nuts were lost by the company that produced the nuts for Perry. The producer went bankrupt and the molds were lost. That is what Perry told me. They also said to let them know if there was a market for the nuts.

I highly doubt that the star washer provided by E-G has anything to do with an attempt to engineer in better current flow into their zinc from the metals of the prop and shaft. The stainless washer and fastener would be a terrible electrical conductor material to use between the zinc sleeve and the bronze core, especially considering the extremely low current that would exist. The small contact surface area would even add to the problem. A bronze star washer and fastener would be far more appropriate to conduct current. My question in the last post about the contact area between the inside of the zinc sleeve and the core was very important for that exact reason. You answered with what I'd hoped to hear, that the inside of your zinc sleeve looked very intact. My assumption is that the star washer is strictly there to perform as a locking mechanism. Evidently it hasn't performed that well for some as they have come loose and even been lost by some users. We don't know that the nylon coated fastener used in the Martyr performs any better.

I believe I already posted contact info for Canada Metal in an earlier post. If you can't find it give West Marine a call and ask them to connect you with technical info on Canada Metal zincs, they'll connect you to the company.