Prop Zinc

[Bill]

Hello to All

Thanks to alll who responded to the Electrical Panel ??'s and now for a new one.

Where do I get a new perry nut for the prop? More importantly, how do I get the old one off?

Thanks in Advance

Bill



cd25d@rhapsodysails.com

[Tom]

Hello to All

Thanks to alll who responded to the Electrical Panel ??'s and now for a new one.

Where do I get a new perry nut for the prop? More importantly, how do I get the old one off?

Thanks in Advance

Bill

There are basically two types of Perry Nuts in the world. Boat US and West stock the electroguard brand, but most Cape Dorys came with the original design by Perry. The original Perry is shorter and fatter and the zincs you buy from West or Boats won't fit. The electroguard brand has a round head quarter twenty stainless bolt that unscrews. Just imagine you're unscrewing something that screws into the end of the prop shaft and you'll find it. Once the screw is removed the zinc just slides off. The bronze part of the nut stays on the shaft and screws onto the shaft which is threaded on the end. It is held in place with a cotter pin through the shaft. Normally you don't remove the bronze part, you just slide a new zinc over the bronze nut and cinch it down with the round head bolt and star washer. If you are removing the prop, you pull the cotter pin and unscrew the bronze nut which is a normal right hand thread. I see in the new West catalog that we just received that they talk about a "Martyr" brand so maybe they've switched brands again. (page 454 in West 2001 catalog)



TomCambria@mindspring.com

[ken coit]

Bill,

If you do a search on this site for "perry nut" you will pull up dozens of links to messages on the perry nut. I think their contact info is:

Perry's Boat Harbor
500 Perry's Island Rd., Isleton, CA
(916)777-5000

I'm not sure of the size of the 25D shaft and threads.

West Marine offers a similar product. I think they may refer to them as prop anodes.

Good sailing soon!

Ken

Hello to All

Thanks to alll who responded to the Electrical Panel ??'s and now for a new one.

Where do I get a new perry nut for the prop? More importantly, how do I get the old one off?

Thanks in Advance

Bill

parfait@nc.rr.com

[D. Stump, Hanalei]

Tom,

Yes, you are correct, there is a difference. One I noted was that the original Perry nut had the cotter pin pass through both the bronze shaft nut AND the zinc. The ElectroGuard has the pin only through the nut and as you describe, the zinc is held on with a 1/4-20 SS bolt through the aft end of the zinc into the cage fitting that is part of the nut.

I have been using the ElectroGuard the last few years(as the Perry is hard to find around here) and have spun off a couple of zincs when that bolt let go. To avoid that, I now secure the bolt with Life Caulk when I install it, even if I do it underwater with the mask and flippers on!

Jeez, we must be getting close to Spring launch....Bill has me thinking about all the chores to complete before launch, and it's going to be wind chills of ZERO here tonight!!!

Dave Stu8mp

[charlie palumbo]

Hello to All

Thanks to alll who responded to the Electrical Panel ??'s and now for a new one.

Where do I get a new perry nut for the prop? More importantly, how do I get the old one off?

Thanks in Advance

Bill, since I have had my cape dory,I have only used the donut, collar type zinc for the prop...they work fine and are easy on and easy off.




jcp1347@gateway.net

[Bob Loewenstein]

I use the original Perry Nut (you can order it from California or Mass). I don't have the phone number here, but do a search on this bboard.

While in Annapolis, I saw the there were less expensive zincs similar to the Perry nut at Fawcett's...like $10 or less. The threads were the correct size for my 1" shaft. I'll be trying this zinc when it's time to replace.

One thing about the shaft zincs that sit forward of the prop: I've been told that if it's too close to the cutless bearing that it could impede the cooling water flow to the bearing. Not sure whether this is something to be concerned about or not.



rfl@yerkes.uchicago.edu

[Larry DeMers]

Dave,

Just a possible caution about not getting too rambunctious with the lifecaulk on the zinc. Don't forget that you have a low voltage connection to that nut via the wire cage and bolt thread. That connection must be the very lowest resistance possible, or the zinc will be less and less effective. In other words, you are trying to bond the zinc to the prop, shaft, and probably the engine too as if it were one. If there is some resistance in that path, the voltage difference between the zinc and the stuff to be protected will increase, leading to increased electrolysis. (kinda like the zinc wasn't there partially). How about using a version of lock-tite instead? I do not know if locktite is ok used undewater or not..as long as it has hardened, it would seem to be ok. If it were applied to the threads, then the screw was inserted, the threads would still make electrical contact at the interface of the screws thread to the bolts thread. The screw would be securely held there against vibration, and there would be loads of physical contact of the zinc to the cage and shaft nut etc.
Or maybe there is still enough incidental contact such that there is no problem? I use the same device, and so far, it looks like new. (but the prop keeps getting smaller and smaller!...just kidding ;^) )

Boy talk about getting the boat bug! We usually have 35-40 deg. out by this time, and the snow is usually getting pretty crispy and scarce. But not this year! I *still* have 4ft. of snow in the yard, and it was -20 deg. actual temp last night..

Come on Spring!

Larry DeMers

Tom,

Yes, you are correct, there is a difference. One I noted was that the original Perry nut had the cotter pin pass through both the bronze shaft nut AND the zinc. The ElectroGuard has the pin only through the nut and as you describe, the zinc is held on with a 1/4-20 SS bolt through the aft end of the zinc into the cage fitting that is part of the nut.

I have been using the ElectroGuard the last few years(as the Perry is hard to find around here) and have spun off a couple of zincs when that bolt let go. To avoid that, I now secure the bolt with Life Caulk when I install it, even if I do it underwater with the mask and flippers on!

Jeez, we must be getting close to Spring launch....Bill has me thinking about all the chores to complete before launch, and it's going to be wind chills of ZERO here tonight!!!

Dave Stu8mp

demers@sgi.com

[Keith]

Hello to All

Thanks to alll who responded to the Electrical Panel ??'s and now for a new one.

Where do I get a new perry nut for the prop? More importantly, how do I get the old one off?

Thanks in Advance

Bill:

I replaced the perry nut on Witness last spring. I will get the name of the co. in Haver de Grace, MD and send it to you directly. The guy there knows Cape Dories, and had the item in stock - got it to me right away.




kwoodlaw@arkansas.net

[M. R. Bober]

With regard to the ElectroGuard zincs:
I have found that as the zinc erodes, there is a problem with the allen bolt's security (i.e. with space between the underside of the bolt head & the aft end of the zinc, the bolt will loosen & the zinc can come off). I have made it a practice to check the fit regularly. I usually can put a half turn (or more) on the bolt.
Mitchell Bober
RESPITE
CD330

[Tom]

Tom,

Yes, you are correct, there is a difference. One I noted was that the original Perry nut had the cotter pin pass through both the bronze shaft nut AND the zinc. The ElectroGuard has the pin only through the nut and as you describe, the zinc is held on with a 1/4-20 SS bolt through the aft end of the zinc into the cage fitting that is part of the nut.

I have been using the ElectroGuard the last few years(as the Perry is hard to find around here) and have spun off a couple of zincs when that bolt let go. To avoid that, I now secure the bolt with Life Caulk when I install it, even if I do it underwater with the mask and flippers on!

Jeez, we must be getting close to Spring launch....Bill has me thinking about all the chores to complete before launch, and it's going to be wind chills of ZERO here tonight!!!

Dave Stu8mp

Dave, A year or two back I posted a msg to the BB about using 5200 on the bolt that holds the zinc to the bronze nut. 5200 does not become permanent when used under water like this. The bolt can be screwed out of it with a little effort, and the 5200 crumbles away like dried toothpaste. Life Caulk is not an adhesive caulk but just fills gaps. What would be the purpose of putting Lifecaulk on the bolt? The adhesion you would get out of it would be minimal and it might actually work as a lubricant. I picked up the trick of using 5200 from workers in a boatyard, but I've never heard of anyone using Lifecaulk which is polysulfide based rather than polyurethane based.



TomCambria@mindspring.com

[Craig Urquhart]

Larry,
Like Dave, I secure my ElectroGuard Zinc with Silicone Adhesive. Rather than going at the threads of the 1/4-20 screw, I pack the Silicone into the tail end of the zinc, covering the screw head to prevent it from backing out. In this way, I avoid compromising the bonding of the zinc to the shaft, and have not lost a zinc in years.

Craig
Satu CD27 #272

Dave,

Just a possible caution about not getting too rambunctious with the lifecaulk on the zinc. Don't forget that you have a low voltage connection to that nut via the wire cage and bolt thread. That connection must be the very lowest resistance possible, or the zinc will be less and less effective. In other words, you are trying to bond the zinc to the prop, shaft, and probably the engine too as if it were one. If there is some resistance in that path, the voltage difference between the zinc and the stuff to be protected will increase, leading to increased electrolysis. (kinda like the zinc wasn't there partially). How about using a version of lock-tite instead? I do not know if locktite is ok used undewater or not..as long as it has hardened, it would seem to be ok. If it were applied to the threads, then the screw was inserted, the threads would still make electrical contact at the interface of the screws thread to the bolts thread. The screw would be securely held there against vibration, and there would be loads of physical contact of the zinc to the cage and shaft nut etc.
Or maybe there is still enough incidental contact such that there is no problem? I use the same device, and so far, it looks like new. (but the prop keeps getting smaller and smaller!...just kidding ;^) )

Boy talk about getting the boat bug! We usually have 35-40 deg. out by this time, and the snow is usually getting pretty crispy and scarce. But not this year! I *still* have 4ft. of snow in the yard, and it was -20 deg. actual temp last night..

Come on Spring!

Larry DeMers

Tom,

Yes, you are correct, there is a difference. One I noted was that the original Perry nut had the cotter pin pass through both the bronze shaft nut AND the zinc. The ElectroGuard has the pin only through the nut and as you describe, the zinc is held on with a 1/4-20 SS bolt through the aft end of the zinc into the cage fitting that is part of the nut.

I have been using the ElectroGuard the last few years(as the Perry is hard to find around here) and have spun off a couple of zincs when that bolt let go. To avoid that, I now secure the bolt with Life Caulk when I install it, even if I do it underwater with the mask and flippers on!

Jeez, we must be getting close to Spring launch....Bill has me thinking about all the chores to complete before launch, and it's going to be wind chills of ZERO here tonight!!!

Dave Stu8mp

Satu@gwi.net

[Tom]

Dave,

Just a possible caution about not getting too rambunctious with the lifecaulk on the zinc. Don't forget that you have a low voltage connection to that nut via the wire cage and bolt thread. That connection must be the very lowest resistance possible, or the zinc will be less and less effective. In other words, you are trying to bond the zinc to the prop, shaft, and probably the engine too as if it were one. If there is some resistance in that path, the voltage difference between the zinc and the stuff to be protected will increase, leading to increased electrolysis. (kinda like the zinc wasn't there partially). How about using a version of lock-tite instead? I do not know if locktite is ok used undewater or not..as long as it has hardened, it would seem to be ok. If it were applied to the threads, then the screw was inserted, the threads would still make electrical contact at the interface of the screws thread to the bolts thread. The screw would be securely held there against vibration, and there would be loads of physical contact of the zinc to the cage and shaft nut etc.
Or maybe there is still enough incidental contact such that there is no problem? I use the same device, and so far, it looks like new. (but the prop keeps getting smaller and smaller!...just kidding ;^) )

Boy talk about getting the boat bug! We usually have 35-40 deg. out by this time, and the snow is usually getting pretty crispy and scarce. But not this year! I *still* have 4ft. of snow in the yard, and it was -20 deg. actual temp last night..

Come on Spring!

Larry DeMers

Larry, Straighten me out here. I thought that the contact between the zinc and the propshaft was via the bronze nut. The inside of the zinc is in contact with the outside of the bronze nut it's entire length and also at the bottom of the zinc where it comes against the collar on the bronze nut. The continuity between the quarter twenty bolt that holds the zinc on and the bronze nut that it threads into I always thought was immaterial, because the inside of the zinc is in contact with the outside of the bronze nut on it's entire surface. Thus you've got several square inches of contact even if you didn't have a bolt there. The bronze nut portion screws onto the prop shaft so you've got absolute contact between the shaft and the bronze nut that slattering 5200 all over the bolt wouldn't affect in any way. You've got contact between the inside of the zinc and the outside of the bronze nut that slattering 5200 on the bolt wouldn't affect in any way. What am I missing here?

Tom,

Yes, you are correct, there is a difference. One I noted was that the original Perry nut had the cotter pin pass through both the bronze shaft nut AND the zinc. The ElectroGuard has the pin only through the nut and as you describe, the zinc is held on with a 1/4-20 SS bolt through the aft end of the zinc into the cage fitting that is part of the nut.

I have been using the ElectroGuard the last few years(as the Perry is hard to find around here) and have spun off a couple of zincs when that bolt let go. To avoid that, I now secure the bolt with Life Caulk when I install it, even if I do it underwater with the mask and flippers on!

Jeez, we must be getting close to Spring launch....Bill has me thinking about all the chores to complete before launch, and it's going to be wind chills of ZERO here tonight!!!

Dave Stu8mp

TomCambria@mindspring.com

[D. Stump, Hanalei]

!!!

[Duncan Maio]

One thing about the shaft zincs that sit forward of the prop: I've been told that if it's too close to the cutless bearing that it could impede the cooling water flow to the bearing. Not sure whether this is something to be concerned about or not.

For the past several seasons, I have used a donut zinc on the shaft between the prop and cutlass bearing. There is not quite enough room for the standard West Marine bearing, so I have to have it machined down to about 1" thick, and there has always been some left at the end of the season. Never had any problems with lubrication of the stuffing box, either with conventional packing or (last season) Dripless packing.

If Remedy is like most CD27s, there would not be room for a standard zinc. We use the donut because the end of the shaft was damaged by a mechanic removing the prop several years ago, and there is not enough shaft left to attach a perry-type nut.

If anyone needs a donut zinc milled down, let me know. I can supply them at West Marine's list price ($13.00 for the 1" collar, plus shipping) if done in bulk. I won't be doing mine until early April, so let me know.

Duncan Maio
s/v Remedy
CD27 #37
Bristol, RI



mail@mysticmarine.net

[Bob Loewenstein]

Boy talk about getting the boat bug! We usually have 35-40 deg. out by this time, and the snow is usually getting pretty crispy and scarce. But not this year! I *still* have 4ft. of snow in the yard, and it was -20 deg. actual temp last night..

Come on Spring!

Larry DeMers

Larry, Thanks for the weather report. We're coming up your way (Hurley) to ski tomorrow through Sunday. While I certainly think about boats, I haven't given up the ski bug just yet.

Bob



rfl@yerkes.uchicago.edu