I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
Peter, S/V Brolga
Cape Dory 26, Hull #42
pkozup@juno.com
Is Barrier Coat needed??
Moderator: Jim Walsh
-
charlie palumbo
Re: Is Barrier Coat needed??
Pete,Peter wrote: I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
Peter, S/V Brolga
Cape Dory 26, Hull #42
While I have owned sailboats for 25 years I am not an authority on the subject. However here is what I Would do. If the bottom is in moderately decent shape, and you intend to haul in the fall, I would give it a good sanding with 80 grit, clean thoroughly with a tack cloth and put on one coat of moderately thinned bottom paint. If it is going to stay in the water all year round I would lay on two coats of thinned bottom paint. If the bottom is in bad shape.....peeling etc.,I would take it down with 80 grit and wipe it thoroughly with fiberglass cleaning solvent. Now comes decision time.....some people swear by epoxy undercoat, I am not one of those.I use it for spot repair on the hull, I am not a strong advocate of the six coat epoxy application, unless the boat has clearly shown that it is blister prone. In other words, I would go from season to season evaluating the bottom. If you find after a season that you have a blister problem, you can then use the epoxy system. provided you haul out in the fall, one year should not cause you any major problems.
The trick to applying bottom paint, is keeping it thin. Blisters are more prone to develop when you have several old thick layers of paint that retain moisture. most people think that once you apply epoxy undercoat, your problem is solved for the life of the boat. Not true.
epoxy is very good, but not perfect. If you ever have to remove old epoxy, you are in for a tough job. I would patch any voids in the hull using west system 406.
Good luck.........Charlie p cd36 summer wind N.y.
jcp1347j@aol.com
-
Bill Goldsmith
Re: Is Barrier Coat needed??
I agree with Charlie that a barrier coat is not absolutely necessary but I do believe it is a safeguard. Alot depends on the condition of the gelcoat, separate and apart from blistering.
When I bought Second Chance 4 years ago there was no evidence of blistering, but I took off all the old bottom paint to examine the condition of the hull, and start fresh with the newer ablative paints. I found that in some areas the gelcoat had been sanded woefully thin, and in other areas there were small dings gouges and nicks. So even though there were no blisters, I barrier coated the hull because of the thin gel and to fair over some of the minor defects.
My feeling was that as long as I had the hull stripped, I might as well barrier coat it to seal it up.
If your hull has no blisters and the gelcoat is in good shape, you can skip the barrier coat. It is a big job and if you hire it out it is expensive. However, if you are planning to strip the old bottom paint anyway, it is a good time to do the barrier coat.
No one knows how long older glass-reinforced plastic hulls will remain servicable, especially one that is free of blisters. They just keep on going. By doing the barrier coat, I figure I gave Second Chance a longer lease on life.
Bill Goldsmith
CD27#173
Second Chance
Croton-on-Hudson, NY
.: I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
goldy@bestweb.net
When I bought Second Chance 4 years ago there was no evidence of blistering, but I took off all the old bottom paint to examine the condition of the hull, and start fresh with the newer ablative paints. I found that in some areas the gelcoat had been sanded woefully thin, and in other areas there were small dings gouges and nicks. So even though there were no blisters, I barrier coated the hull because of the thin gel and to fair over some of the minor defects.
My feeling was that as long as I had the hull stripped, I might as well barrier coat it to seal it up.
If your hull has no blisters and the gelcoat is in good shape, you can skip the barrier coat. It is a big job and if you hire it out it is expensive. However, if you are planning to strip the old bottom paint anyway, it is a good time to do the barrier coat.
No one knows how long older glass-reinforced plastic hulls will remain servicable, especially one that is free of blisters. They just keep on going. By doing the barrier coat, I figure I gave Second Chance a longer lease on life.
Bill Goldsmith
CD27#173
Second Chance
Croton-on-Hudson, NY
.: I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
Peter wrote: Peter, S/V Brolga
Cape Dory 26, Hull #42
goldy@bestweb.net
-
Matthew
Re: Is Barrier Coat needed??
Fiberglass will absorb water and eventually delaminate, that is the reason to apply a barrier coat. I am uncertain that if epoxy is used instead of polyester resins that a barrier coat becomes unnecessary. I don't believe it in general and I would certainly not believe it unless you can obtain a written spec from the manufacturer so saying it. West epoxy, for one example, explicitly states that it will absorb water and that a barrier coat of some kind is required. Typically on your age boat there is a gel coat below (and above) the water line, this is a "barrier coat", ie it retards the absorbsion of water. If you grind out a blister, you invariably remove the barrier coat, whether epoxy, gel coat, imron, awlgrip or whatever. You must either re-gel or apply some kind of barrier coat before bottom paint. If your gel coat has become worn, pitted, thin, then one fix is to apply an epoxy based barrier coat (an additive) to the gel coat. I did this while in Trinidad and the preparation is fairly intensive - you must first strip off all the old bottom paint (I say strip, but you really scrape - all solvent strippers I've known damage the fiberglass) and then sand prepare the gel. However, if the gel coat is in good shape, there is no need to apply epoxy. Before applying bottom paint, in any case, you will want to apply a primer to whatever barrier coat exists or you add. Finally, anti-fouling paint is never "required". Racing boats which are rarely in the water never use anti-fouling paint, but rather teflon paints and such to speed the vessel. Antifouling paint does one thing, it keeps a cleaner bottom, and therefore a better performance for boats generally in the water. As for fresh water, go look at a piling and see what grows - that is what will be one an untreated bottom sooner than you can believe.charlie palumbo wrote:Pete,Peter wrote: I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
Peter, S/V Brolga
Cape Dory 26, Hull #42
While I have owned sailboats for 25 years I am not an authority on the subject. However here is what I Would do. If the bottom is in moderately decent shape, and you intend to haul in the fall, I would give it a good sanding with 80 grit, clean thoroughly with a tack cloth and put on one coat of moderately thinned bottom paint. If it is going to stay in the water all year round I would lay on two coats of thinned bottom paint. If the bottom is in bad shape.....peeling etc.,I would take it down with 80 grit and wipe it thoroughly with fiberglass cleaning solvent. Now comes decision time.....some people swear by epoxy undercoat, I am not one of those.I use it for spot repair on the hull, I am not a strong advocate of the six coat epoxy application, unless the boat has clearly shown that it is blister prone. In other words, I would go from season to season evaluating the bottom. If you find after a season that you have a blister problem, you can then use the epoxy system. provided you haul out in the fall, one year should not cause you any major problems.
The trick to applying bottom paint, is keeping it thin. Blisters are more prone to develop when you have several old thick layers of paint that retain moisture. most people think that once you apply epoxy undercoat, your problem is solved for the life of the boat. Not true.
epoxy is very good, but not perfect. If you ever have to remove old epoxy, you are in for a tough job. I would patch any voids in the hull using west system 406.
Good luck.........Charlie p cd36 summer wind N.y.
Matt s/v Tinker cd30
matkinson54@hotmail.com
-
Ed Haley
Re: Is Barrier Coat needed??
Peter:
If it were me sanding the entire bottom down to the gelcoat, when it comes time to applying barriers to protect the hull of your lovely CD, I would not spare a nickel in preventative maintenance. I would apply several barrier coats and then whatever bottom paint you decide is best for your needs. As far as I'm concerned, the barrier coat represents the "bottom line" of protection. I would want to have it there and not need it than to need it and not have it there!
Sure, it's a lot of work and expense correctly putting down a barrier coat but it beats removing the whole bottom twice. Do it right the first time even if it appears to be overly protective. IMHO.
Ed Haley
s/v Mokita
CD330 #1
Mystic, CT (temporary)
Lake Ontario (eventually)
eghaleyNOSPAM@twcny.rr.com
If it were me sanding the entire bottom down to the gelcoat, when it comes time to applying barriers to protect the hull of your lovely CD, I would not spare a nickel in preventative maintenance. I would apply several barrier coats and then whatever bottom paint you decide is best for your needs. As far as I'm concerned, the barrier coat represents the "bottom line" of protection. I would want to have it there and not need it than to need it and not have it there!
Sure, it's a lot of work and expense correctly putting down a barrier coat but it beats removing the whole bottom twice. Do it right the first time even if it appears to be overly protective. IMHO.
Ed Haley
s/v Mokita
CD330 #1
Mystic, CT (temporary)
Lake Ontario (eventually)
eghaleyNOSPAM@twcny.rr.com
-
Catherine Monaghan
Re: Is Barrier Coat needed??
Peter,
Cape Dory used a polyester, not vinyl ester, resin in the layup of the hull and blisters are a known problem with these boats. Irregardless of where you'll be using your boat, if she's going to remain in the water during the season rather then hauled after each use, a bottom paint should be applied. Your Cape Dory will eventually need a barrier coat, but when to do it is up to you.
Cathy
CD32 <a href="http://www.hometown.aol.com/bcomet/real ... ization</a>, #3
Rahway, NJ
Raritan Bay
catherine_monaghanNOSPAM@merck.com
Cape Dory used a polyester, not vinyl ester, resin in the layup of the hull and blisters are a known problem with these boats. Irregardless of where you'll be using your boat, if she's going to remain in the water during the season rather then hauled after each use, a bottom paint should be applied. Your Cape Dory will eventually need a barrier coat, but when to do it is up to you.
Cathy
CD32 <a href="http://www.hometown.aol.com/bcomet/real ... ization</a>, #3
Rahway, NJ
Raritan Bay
Peter wrote: I've been told by a fairly knowledgeable friend (not a Cape Dory owner) that sometimes a barrier coat is not needed to protect the fiberglass from blistering. I was thinking of sanding off all the old paint on my CD26 and applying a barrier coat before any sort of anti-fouling. I'm not really certain whether or not an anti-foul is needed for a boat that has only seen freshwater (Lake Erie). Blistering is another matter, though, and if I need to apply a barrier coat I will go to the trouble to do so. The friend stated that some boats with newer fiberglass hulls that used a modified epoxy or vinyl esters did not need a barrier coat. My boat is a 1986 model, and I'm wondering if anyone knows enough about the fiberglass to tell whether it needs protection against blistering by the use of a barrier coat. I was planning to get started on this this coming week, so if anyone knows whether or not a barrier coat is needed they could save me a lot of work. Thanks for any help you can give me.
Peter, S/V Brolga
Cape Dory 26, Hull #42
catherine_monaghanNOSPAM@merck.com