More CD30 Holding Tank Info.

[John R.]

Okay, here it goes:

For those following this thread from the past message I have come up with new information from Kracor Inc. regarding replacing the original bow holding tank on our '83 CD30.

Kracor still has the aluminum tank mold used to form the polyethelene holding tank. They are willing to make a new replacement tank. The problem is the cost. Not the tank cost but the "setup cost". They charge a $200 fee for interrupting their normal production and installing the other mold on their machine and producing the one tank.
The tank itself is $161.24, not too awfully bad for a unique tank that is very geometric in design and out of production. Remember we are not talking about your basic rectangular tank like a Todd tank.

The tank is still made as a HDPE tank (high density polyethelene). Those tanks have a life expectancy of 10 - 15 years maximum. Less for a low density version such as is used for water tanks. They apologized for telling me they had never heard of any cracks in the tanks in over twenty years, that was meant for the "crosslinked polyethelene tanks". They use aluminum or stainless ports for the fittings and the "cross linked" polyethelene molecules won't allow cracking like the linear molecules in a high or low density tank.

They told me according to their records Cape Dory was informed of the limited life span of the HDPE tanks. The particular bow tank I have a problem with was also used in the following boats: CD30,CD28,CD36, Intrepid 9M, Intrepid 28, Intrepid 35 (didn't know there was such an animal). All tanks made by Kracor in CD's and Intrepids will have the same cracking problem in time according to Kracor, it's the nature of the material I was told. Keep a close eye on areas right around the tank connection fittings. You can try and repair small cracks. Call Kracor, see my earlier post for contact info.

The model number of the bow tank discussed above is Kracor # 2-6256.

The mold number is Kracor #5059-24.

The tank design date is 3/30/78.

Capacity is 24 gallons.

They faxed me a copy of the original engineering drawing. Really considerate of them. They stated that heat is the worst enemy of the polyethelene. That is probably why they crack at and near the heated connection fitting ports. The rest of the tank I'm having problems with is in as new condition.

So what is the solution.......pay $361 for a very limited lifespan exact replacement or........

1) have one fabricated from aluminum exactly like it. (salt damage?)

2) build one out of plywood,glass and West epoxy exactly like it.

3) install a Nauta or plastimo flexible tank and free up more storage space under the V-berth.(note: the Nautas have a special "Nadra" liner that will not let odors permeate through it - guaranteed).

4) try and find someone that can fabricate a copy of the original
out of PVC. (which would last a long time).

Or any other ideas out there?

[John Nuttall]

John R.,
I've beenfollowing the thread closely because I have water tank leaks at a fill fitting. Possibly an overtightening problem. Let me comment on your list of "solutions":

Flexible Tank: Please contact Peggy @ Peel Products re this. According to her this is a major no-no. Apparently there are 2 concerns here. Firstly, they never vent properly, and therefore you will be plagued with odors - big time! Secondly, the bags move and eventually abrade and leak. You can find her address using the search feature, it's in some old posts.

Plastic welding: During my younger ski bum days, I worked at a Ski shop in Steamboat Springs and got pretty good with a plastic welder. The welder look like a soldering iron with a feeder tube for the plastic "rods". Today's welders are probably more sophisticated. The right technician could cut out the cracks and rebuild the weak spots on the tank. You could even have the old hole sealed up and redrilled or relocated on the tank (if possible) to an area that never got overstressed. Do you have any good skishops in your area?

Good Luck,
John Nuttall
s/v Aimless
CD31 #28
Oriental, NC



nuttallj@msn.com

[Don Carr]

I have been following the holding tank thread with some interest. Although I am not an expert in plastics I do know that any petroleum based plastic will harden and become brittle over time. Which may explain some of the discoveries of 'cracked' fittings.
You apparently are somewhat set in an 'in kind' replacement. Wouldn't it make sense to rally all the folks affected by this problem and make a group purchasing offer to KRACOR. Since they have the molds it is simply a time and materials question. Assuming you get 20 or so purchasers your cost per unit could be negotiated down a bit. Just my $.02 worth. Personally my Sealand Porta Potti works quite well for my needs on a CD25.



carrd48@netzero.com

[Olli Wendelin]

The price seems a bit steep for a 10 year lifespan. I would recommend fabricating a new tank from monel or fiberglass.

Could you e-mail or fax me a copy of the engineering drawing? I may build one for my boat eventually. My fax number is 843-974-4233.

Olli Wendelin
BLUE MOON
Charleston, SC



wendelin@spawar.navy.mil

[John R.]

John R.,
I've beenfollowing the thread closely because I have water tank leaks at a fill fitting. Possibly an overtightening problem. Let me comment on your list of "solutions":

Flexible Tank: Please contact Peggy @ Peel Products re this. According to her this is a major no-no. Apparently there are 2 concerns here. Firstly, they never vent properly, and therefore you will be plagued with odors - big time! Secondly, the bags move and eventually abrade and leak. You can find her address using the search feature, it's in some old posts.

Plastic welding: During my younger ski bum days, I worked at a Ski shop in Steamboat Springs and got pretty good with a plastic welder. The welder look like a soldering iron with a feeder tube for the plastic "rods". Today's welders are probably more sophisticated. The right technician could cut out the cracks and rebuild the weak spots on the tank. You could even have the old hole sealed up and redrilled or relocated on the tank (if possible) to an area that never got overstressed. Do you have any good skishops in your area?

Good Luck,
John Nuttall
s/v Aimless
CD31 #28
Oriental, NC

Heh John,

I've already been in touch with Peg Hall and she says the flexible tanks have a problem with vent clogging and that causes pressure in the tank and some blow the fittings from excessive pressure. I know these tanks are used a lot, I also know there is a broad range of quality between different brands. I can't imagine they all fall victim to clogged vents and fitting blow outs. I'm seriously considering the Nauta flexible tank. They look to be very high quality and fittings can be installed anywhere and the fittings themselves look extremely well made, far better than the polyethelene tanks.

I may just build a duplicate out of plywood and fiberglass with West System. I don't believe there would be failures like with all these other tanks. Aluminum can't be used because of urine's acidity and they start to leak at the welds in a few years indicates Peg Hall.

Monel is out of the question $$$ wise. PVC is still an option if I can find someone who can make one.

My tank can't be welded, the cracks are in really bad locations. In fact one runs completely through the vent port fitting. This is why I do not want another one of these tanks. Who needs to revisit this issue again in a few years. There is enough other boat stuff to be concerned with.

A couple of manufacturers I've spoken with say overtightening the hose barbs into the tank fittings won't cause the cracks in the polyethelene. I think the cracks just form over time due to weakness in the tank wall where the fitting ports are installed with heat. They say heat is a big problem for polyethelene.

How is your Bristol Finish project coming along?

[John]

The price seems a bit steep for a 10 year lifespan. I would recommend fabricating a new tank from monel or fiberglass.

Could you e-mail or fax me a copy of the engineering drawing? I may build one for my boat eventually. My fax number is 843-974-4233.

Olli Wendelin
BLUE MOON
Charleston, SC

Olli,

How would you build one from fiberglass? I've been considering building one out of plywood and glass and West epoxy. At least I know the epoxy won't permeate in time and I know the seams would never leak. What else would there be to worry about? I figure I could build it for around $60 and do a real nice job and it would look as good as a factory tank gelcoated. I could use regular bronze thru hulls for the fittings and never need to worry again. I could place the fittings exactly where I need them, rather than buried under the anchor locker floor where they can't be serviced without pulling out the tank (ridiculous design).

Give me some feedback on what you are considering doing. I'll fax ya the drawing. Twice through the fax so the quality may not be to great.
What size CD is Blue Moon?

[John]

I have been following the holding tank thread with some interest. Although I am not an expert in plastics I do know that any petroleum based plastic will harden and become brittle over time. Which may explain some of the discoveries of 'cracked' fittings.
You apparently are somewhat set in an 'in kind' replacement. Wouldn't it make sense to rally all the folks affected by this problem and make a group purchasing offer to KRACOR. Since they have the molds it is simply a time and materials question. Assuming you get 20 or so purchasers your cost per unit could be negotiated down a bit. Just my $.02 worth. Personally my Sealand Porta Potti works quite well for my needs on a CD25.

I don't know of anyone else that needs one.

[Tom]

Okay, here it goes:

For those following this thread from the past message I have come up with new information from Kracor Inc. regarding replacing the original bow holding tank on our '83 CD30.

Kracor still has the aluminum tank mold used to form the polyethelene holding tank. They are willing to make a new replacement tank. The problem is the cost. Not the tank cost but the "setup cost". They charge a $200 fee for interrupting their normal production and installing the other mold on their machine and producing the one tank.
The tank itself is $161.24, not too awfully bad for a unique tank that is very geometric in design and out of production. Remember we are not talking about your basic rectangular tank like a Todd tank.

The tank is still made as a HDPE tank (high density polyethelene). Those tanks have a life expectancy of 10 - 15 years maximum. Less for a low density version such as is used for water tanks. They apologized for telling me they had never heard of any cracks in the tanks in over twenty years, that was meant for the "crosslinked polyethelene tanks". They use aluminum or stainless ports for the fittings and the "cross linked" polyethelene molecules won't allow cracking like the linear molecules in a high or low density tank.

They told me according to their records Cape Dory was informed of the limited life span of the HDPE tanks. The particular bow tank I have a problem with was also used in the following boats: CD30,CD28,CD36, Intrepid 9M, Intrepid 28, Intrepid 35 (didn't know there was such an animal). All tanks made by Kracor in CD's and Intrepids will have the same cracking problem in time according to Kracor, it's the nature of the material I was told. Keep a close eye on areas right around the tank connection fittings. You can try and repair small cracks. Call Kracor, see my earlier post for contact info.

The model number of the bow tank discussed above is Kracor # 2-6256.

The mold number is Kracor #5059-24.

The tank design date is 3/30/78.

Capacity is 24 gallons.

They faxed me a copy of the original engineering drawing. Really considerate of them. They stated that heat is the worst enemy of the polyethelene. That is probably why they crack at and near the heated connection fitting ports. The rest of the tank I'm having problems with is in as new condition.

So what is the solution.......pay $361 for a very limited lifespan exact replacement or........

1) have one fabricated from aluminum exactly like it. (salt damage?)

2) build one out of plywood,glass and West epoxy exactly like it.

3) install a Nauta or plastimo flexible tank and free up more storage space under the V-berth.(note: the Nautas have a special "Nadra" liner that will not let odors permeate through it - guaranteed).

4) try and find someone that can fabricate a copy of the original
out of PVC. (which would last a long time).

Or any other ideas out there?

Just a thought, but have you checked with Robinhood Marine to see what tank they are putting in the Robinhood 30? They may have a tank that will set right in there. Either fabricated for the new boats or left over from the old days.

Isn't it interesting how when you first talk to a manufacturer they've got something off the shelf that will cure your problem and they've never had a problem like the one you're describing. Then when you drum up volumes of people with the exact same problem, it turns out they don't have a cure, the type of tank you have can't be fixed, and if they sell you a new one they can't guarantee it. What happened to those 20 years without a failure?

BTW if you work with Crosslink 3 you do have to "conditon" it with a propane torch before any patch. You quickly run the blue flame over the material, but you don't do the actual weld with the propane torch. At least that's what their factory rep told us. Before you just heave the old tank out why not practice repairing it with the welding rod they send you and see what it's like to repair one? You may need this knowledge down the line somewhere and it will give you a feel for what can be done and what can't. Some sailing buddy who has no problem now may discover one in a few years and be posting questions here

And finally, if you're going to have Kracor make a new tank in the old mold, why not make it out of the new material that they guarantee rather than the original plastic that apparently was inferior?

Thanks for doing the research on this, John. That's what makes this BB so great.



TomCambria@mindspring.com

[Russell]

Your boat may still be sailed in ten years time, and it would be a shame to set up the same failure mode. I need to replumb our holding tank, and I do not know yet whether it has any structural failings. Maybe I will look at it this weekend.

How is the tank finished? Do they put in the holding port, and any of the fittings?

[John Nuttall]

Hey John R.,

Thanks for asking. The weather is holding me up right now, but I can tell you that last weekend I did a color comparison. Ryan Turner and I grabbed my companionway drop boards and but them next to the toe rail section that has the new finish. The boards have multiple coats of Captains and are in good shape (always covered w/canvas). The color of the Bristol Finish is LIGHTER than Captains. Six coats of Bristol Finish vs maybe sixteen of Captains????

Anyway, the Bristol is a nice warm color, and very glossy. When I get eniugh done worth photographing, I'll get some pix posted !!!

John



nuttallj@msn.com

[John Nuttall]

vinylester resins are. If you use epoxy you are gonna have to seal it because over time moisture will permeate through. ( I see ALLOT of discussion about this subject on the Wooden Boat Forum ).

Don Casey had an example of how to build a frp box in one of his books ( I forget which one ) The basic steps were to build a plywood mold, slather it with a homeade release agent and layer up the glass/resin. Looked pretty simple to me (ignorance is bliss, isn't it?)

G-luck
John



nuttallj@msn.com

[John R.]

Your boat may still be sailed in ten years time, and it would be a shame to set up the same failure mode. I need to replumb our holding tank, and I do not know yet whether it has any structural failings. Maybe I will look at it this weekend.

How is the tank finished? Do they put in the holding port, and any of the fittings?

Hi Russell,

The deal is they can't produce it as a crosslinked molecule polyethelene tank because the fittings for the hose connections have to be molded to the tank as it's made. The fittings in a crosslinked tank are usually aluminum or stainless. They wouldn't be able to get the tank out of the mold. The standard tank that is in the CD is a HDPE (high density polyethelene tank - linear molecule), the ports that the hose connections screw into are LDPE (low density polyethelene - linear molecule). The ports in our CD tanks are installed after the tank is molded unlike a crosslinked tank that has the connections molded in at the same time the tank is molded. The aluminum casting mold our CD tank came out of is still available. They can only produce the HDPE - linear molecule tank from that mold, no crosslinked.

You are absolutely right that it is ridiculous to set up the same failure mode, especially in such a nice boat that we all know has a lot of lifespan ahead of it. After spending the last few days checking out a lot of sources and options I'm getting awful close to just saying I'll make my own, the commercial choices aren't too great for the $$$ from what I've learned and the warranties are a joke. The most promising commercial tank in my opinion that I've found is the Nauta flexible tank but I would want to hear from others that have them before I'd lay down the $$$$.

[John R.]

vinylester resins are. If you use epoxy you are gonna have to seal it because over time moisture will permeate through. ( I see ALLOT of discussion about this subject on the Wooden Boat Forum ).

Don Casey had an example of how to build a frp box in one of his books ( I forget which one ) The basic steps were to build a plywood mold, slather it with a homeade release agent and layer up the glass/resin. Looked pretty simple to me (ignorance is bliss, isn't it?)

G-luck
John

I've seen plenty of live well tanks made with ply, glass and West that are totally waterproof and have been around for years and always have water in them, they don't leak or seep. West even discusses tank construction in their publications and I know a guy who built new H20 tanks in his Moody and has never had any problems with them.

[John R.]

Tom,

First of all I didn't know Robinhood was building a 30. If they are then I have a hunch they might use a similar or the same tank if they are using the same CD30 hull and liner mold. I'll send them an e-mail and follow up with a call on monday. Jeez maybe we should trade our CD30's in on a R30! Sounds good to me......except for the payments, thinking about that option makes a new tank seem pretty attractive and cheap!

You are right that every product is great and there are never any problems until you own one!

I'll keep everybody posted on as much of this saga as possible as it unfolds as I think this is an important matter for everyone with a CD that has polyethelene tanks on board.

Okay, here it goes:

For those following this thread from the past message I have come up with new information from Kracor Inc. regarding replacing the original bow holding tank on our '83 CD30.

Kracor still has the aluminum tank mold used to form the polyethelene holding tank. They are willing to make a new replacement tank. The problem is the cost. Not the tank cost but the "setup cost". They charge a $200 fee for interrupting their normal production and installing the other mold on their machine and producing the one tank.
The tank itself is $161.24, not too awfully bad for a unique tank that is very geometric in design and out of production. Remember we are not talking about your basic rectangular tank like a Todd tank.

The tank is still made as a HDPE tank (high density polyethelene). Those tanks have a life expectancy of 10 - 15 years maximum. Less for a low density version such as is used for water tanks. They apologized for telling me they had never heard of any cracks in the tanks in over twenty years, that was meant for the "crosslinked polyethelene tanks". They use aluminum or stainless ports for the fittings and the "cross linked" polyethelene molecules won't allow cracking like the linear molecules in a high or low density tank.

They told me according to their records Cape Dory was informed of the limited life span of the HDPE tanks. The particular bow tank I have a problem with was also used in the following boats: CD30,CD28,CD36, Intrepid 9M, Intrepid 28, Intrepid 35 (didn't know there was such an animal). All tanks made by Kracor in CD's and Intrepids will have the same cracking problem in time according to Kracor, it's the nature of the material I was told. Keep a close eye on areas right around the tank connection fittings. You can try and repair small cracks. Call Kracor, see my earlier post for contact info.

The model number of the bow tank discussed above is Kracor # 2-6256.

The mold number is Kracor #5059-24.

The tank design date is 3/30/78.

Capacity is 24 gallons.

They faxed me a copy of the original engineering drawing. Really considerate of them. They stated that heat is the worst enemy of the polyethelene. That is probably why they crack at and near the heated connection fitting ports. The rest of the tank I'm having problems with is in as new condition.

So what is the solution.......pay $361 for a very limited lifespan exact replacement or........

1) have one fabricated from aluminum exactly like it. (salt damage?)

2) build one out of plywood,glass and West epoxy exactly like it.

3) install a Nauta or plastimo flexible tank and free up more storage space under the V-berth.(note: the Nautas have a special "Nadra" liner that will not let odors permeate through it - guaranteed).

4) try and find someone that can fabricate a copy of the original
out of PVC. (which would last a long time).

Or any other ideas out there?

Just a thought, but have you checked with Robinhood Marine to see what tank they are putting in the Robinhood 30? They may have a tank that will set right in there. Either fabricated for the new boats or left over from the old days.

Isn't it interesting how when you first talk to a manufacturer they've got something off the shelf that will cure your problem and they've never had a problem like the one you're describing. Then when you drum up volumes of people with the exact same problem, it turns out they don't have a cure, the type of tank you have can't be fixed, and if they sell you a new one they can't guarantee it. What happened to those 20 years without a failure?

BTW if you work with Crosslink 3 you do have to "conditon" it with a propane torch before any patch. You quickly run the blue flame over the material, but you don't do the actual weld with the propane torch. At least that's what their factory rep told us. Before you just heave the old tank out why not practice repairing it with the welding rod they send you and see what it's like to repair one? You may need this knowledge down the line somewhere and it will give you a feel for what can be done and what can't. Some sailing buddy who has no problem now may discover one in a few years and be posting questions here

And finally, if you're going to have Kracor make a new tank in the old mold, why not make it out of the new material that they guarantee rather than the original plastic that apparently was inferior?

Thanks for doing the research on this, John. That's what makes this BB so great.

[John R.]

Tom,

First of all I didn't know Robinhood was building a 30. If they are then I have a hunch they might use a similar or the same tank if they are using the same CD30 hull and liner mold. I'll send them an e-mail and follow up with a call on monday. Jeez maybe we should trade our CD30's in on a R30! Sounds good to me......except for the payments, thinking about that option makes a new tank seem pretty attractive and cheap!

You are right that every product is great and there are never any problems until you own one!

I'll keep everybody posted on as much of this saga as possible as it unfolds as I think this is an important matter for everyone with a CD that has polyethelene tanks on board.

Okay, here it goes:

For those following this thread from the past message I have come up with new information from Kracor Inc. regarding replacing the original bow holding tank on our '83 CD30.

Kracor still has the aluminum tank mold used to form the polyethelene holding tank. They are willing to make a new replacement tank. The problem is the cost. Not the tank cost but the "setup cost". They charge a $200 fee for interrupting their normal production and installing the other mold on their machine and producing the one tank.
The tank itself is $161.24, not too awfully bad for a unique tank that is very geometric in design and out of production. Remember we are not talking about your basic rectangular tank like a Todd tank.

The tank is still made as a HDPE tank (high density polyethelene). Those tanks have a life expectancy of 10 - 15 years maximum. Less for a low density version such as is used for water tanks. They apologized for telling me they had never heard of any cracks in the tanks in over twenty years, that was meant for the "crosslinked polyethelene tanks". They use aluminum or stainless ports for the fittings and the "cross linked" polyethelene molecules won't allow cracking like the linear molecules in a high or low density tank.

They told me according to their records Cape Dory was informed of the limited life span of the HDPE tanks. The particular bow tank I have a problem with was also used in the following boats: CD30,CD28,CD36, Intrepid 9M, Intrepid 28, Intrepid 35 (didn't know there was such an animal). All tanks made by Kracor in CD's and Intrepids will have the same cracking problem in time according to Kracor, it's the nature of the material I was told. Keep a close eye on areas right around the tank connection fittings. You can try and repair small cracks. Call Kracor, see my earlier post for contact info.

The model number of the bow tank discussed above is Kracor # 2-6256.

The mold number is Kracor #5059-24.

The tank design date is 3/30/78.

Capacity is 24 gallons.

They faxed me a copy of the original engineering drawing. Really considerate of them. They stated that heat is the worst enemy of the polyethelene. That is probably why they crack at and near the heated connection fitting ports. The rest of the tank I'm having problems with is in as new condition.

So what is the solution.......pay $361 for a very limited lifespan exact replacement or........

1) have one fabricated from aluminum exactly like it. (salt damage?)

2) build one out of plywood,glass and West epoxy exactly like it.

3) install a Nauta or plastimo flexible tank and free up more storage space under the V-berth.(note: the Nautas have a special "Nadra" liner that will not let odors permeate through it - guaranteed).

4) try and find someone that can fabricate a copy of the original
out of PVC. (which would last a long time).

Or any other ideas out there?

Just a thought, but have you checked with Robinhood Marine to see what tank they are putting in the Robinhood 30? They may have a tank that will set right in there. Either fabricated for the new boats or left over from the old days.

Isn't it interesting how when you first talk to a manufacturer they've got something off the shelf that will cure your problem and they've never had a problem like the one you're describing. Then when you drum up volumes of people with the exact same problem, it turns out they don't have a cure, the type of tank you have can't be fixed, and if they sell you a new one they can't guarantee it. What happened to those 20 years without a failure?

BTW if you work with Crosslink 3 you do have to "conditon" it with a propane torch before any patch. You quickly run the blue flame over the material, but you don't do the actual weld with the propane torch. At least that's what their factory rep told us. Before you just heave the old tank out why not practice repairing it with the welding rod they send you and see what it's like to repair one? You may need this knowledge down the line somewhere and it will give you a feel for what can be done and what can't. Some sailing buddy who has no problem now may discover one in a few years and be posting questions here

And finally, if you're going to have Kracor make a new tank in the old mold, why not make it out of the new material that they guarantee rather than the original plastic that apparently was inferior?

Thanks for doing the research on this, John. That's what makes this BB so great.