We have some crazing on the cockpit seats, especially in the corners where the seat goes from horizontal to vertical. There are also some on the gunwales, and near the fuel fill cap. The crazing in the cockpit will emit a blue stain if the weather is humid. I leave the boat, and if it is foggy overnight, I come back, and there is some bluish stain/discoloration near some cracks. It wipes right off. I bought some SeaFit penetrating epoxy. The packgage says to just brush it on over the cracks and it will penetrate and seal them up. It may take a few coats to build up, but it is paintable. Will this work? The only other thing I have heard of doing is to widen the crack with a rotary tool and then use regular expoxy and then paint. Obviously the penetrating expoxy would be easier as there are many hairline cracks. Has anyone tried this stuff? And what do the blue stains mean?
BSinskie@aol.com
blue stains from crazing
Moderator: Jim Walsh
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john vigor
Re: blue stains from crazing
It's probably the well-known Cape Dory blue ooze. they used cobalt in the curing process and it migrates to the surface occasionaly. You find plenty of fellow sufferers if you search this board with the words "blue stuff."
If your cracks truly are hairline, the stuff to use is a two-part epoxy primer such as Interlux 404/414, specially made to resurface cracked gelcoat. Follow the instructions carefully and paint it to protect it from uv rays.
Cheers,
John Vigor
CD25D Jabula
jvig@whidbey.net
If your cracks truly are hairline, the stuff to use is a two-part epoxy primer such as Interlux 404/414, specially made to resurface cracked gelcoat. Follow the instructions carefully and paint it to protect it from uv rays.
Cheers,
John Vigor
CD25D Jabula
jvig@whidbey.net
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Larry DeMers
Re: blue stains from crazing
Hi John,
The blue ooze is from uncured hardener (with the cobalt that you spoke of), where there is a pocket of resin that didn't kick for one reason or another, allowing a puddle of the resin/hardener to exist in the laminate. If a craze on the surface has this blue stuff coming out, I would label that craze a crack, meaning that water now has a path to the lamination, forming a danger for delamination over time. If the blue stuff comes up because there is a pathway, then water can follow the same pathway down.
I would suggest trying to thin out the blue ooze with alcohol in a syringe, washing the area of the crack thoroughly. Then if there is water penetration into the laminate, you will have to debreed and dry out the crack until the waterlogged material is gone (alcohol helps here too), followed by the standard crack repair with a wetting of the cracks internal surface with epoxy, filling the crack with epoxy with microballoons, gel coat, and finish.
Or some adaptation of that procedure.
I have also noticed this blue ooze coming from hull blisters when they are punctured..on several other brands of boats.
Cheers!!
Larry DeMers
s/v DeLaMer
Cape Dory 30
demers@sgi.com
The blue ooze is from uncured hardener (with the cobalt that you spoke of), where there is a pocket of resin that didn't kick for one reason or another, allowing a puddle of the resin/hardener to exist in the laminate. If a craze on the surface has this blue stuff coming out, I would label that craze a crack, meaning that water now has a path to the lamination, forming a danger for delamination over time. If the blue stuff comes up because there is a pathway, then water can follow the same pathway down.
I would suggest trying to thin out the blue ooze with alcohol in a syringe, washing the area of the crack thoroughly. Then if there is water penetration into the laminate, you will have to debreed and dry out the crack until the waterlogged material is gone (alcohol helps here too), followed by the standard crack repair with a wetting of the cracks internal surface with epoxy, filling the crack with epoxy with microballoons, gel coat, and finish.
Or some adaptation of that procedure.
I have also noticed this blue ooze coming from hull blisters when they are punctured..on several other brands of boats.
Cheers!!
Larry DeMers
s/v DeLaMer
Cape Dory 30
john vigor wrote: It's probably the well-known Cape Dory blue ooze. they used cobalt in the curing process and it migrates to the surface occasionaly. You find plenty of fellow sufferers if you search this board with the words "blue stuff."
If your cracks truly are hairline, the stuff to use is a two-part epoxy primer such as Interlux 404/414, specially made to resurface cracked gelcoat. Follow the instructions carefully and paint it to protect it from uv rays.
Cheers,
John Vigor
CD25D Jabula
demers@sgi.com