rodndtube.com's (OLD) MyPaipoBoards Forums. Reading but no posting on the OLD forums.

[geoffreylevens]

Have some epoxy from old projects so want to glass the current one. Luan ply will get one layer of 4 oz cloth. Guy I got the cloth from gave me dire warnings about resin absorbing properties of Luan. To be sure I actually have enough resin I was thinking of pre-sealing the wood with something else.

Any suggestions as to what I could use and still get a good bond? Urethane spar varnish? Rattle can acrylic paint? Don't even think about it???

Thank you!

[Uncle Grumpy]

I would use the epoxy; either thinned with alcohol or acetone, or better yet, roll on a coat and heat it with a heat gun or blow dryer for maximum penetration.
Anything else will likely compromise the adhesion of glass and resin.
My 2 Cents.
_________________
Prone to ride.

[geoffreylevens]

Thank you U.G. My real issue is chingziness as I currently have, hopefully, just enough resin/hardener to do the job and do not want to spend the money to buy more. In the future I will likely just use varnish but would like to use this up. The alcohol dilution is a good idea, do you know max % dilution or will that vary w/ epoxy brand?

[Uncle Grumpy]

No more then 5%
Here's more info.
http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html
_________________
Prone to ride.

[geoffreylevens]

Thank you for the link! Looks like heating would be much better than thinning. At 80 degrees or so you get almost same viscosity as 5% dilution without weakening strength of finished epoxy.

[mrmike]

when I made wood boats and used epoxy and glass over wood I would seal the wood with good old oil base sanding sealer it worked fine and is cheep
_________________
PAIPO ON
blog http://mrmikespaipos.blogspot.com

[geoffreylevens]

Thanks Mike, I might go with that. My next question was going to be if I would actually save any resin total by using some of what I have to pre-seal the wood or end up using same amount? But the sanding sealer would be nice if I can find a small can like a pint instead of a gallon or rattle can. They exist, just a question if they exist within reasonable distance.

[mrmike]

I think a QT can is as small as you can get but I don't know. I alway use oil base sanding sealer on bare wood before I but enything over it. cost is about $12 a QT but will last for 5 to 6 boards well worth the money
_________________
PAIPO ON
blog http://mrmikespaipos.blogspot.com

[geoffreylevens]

I also just found a 16oz spray can for $5.25 at Lowe's...

[Uncle Grumpy]

Yes, you will save resin by pre sealing.
Not real sure what oil base sanding sealer Mike is referring to.
In my experience, sanding sealer is almost always some kind of premixed shellac; especially if it's in a rattlecan
_________________
Prone to ride.

[geoffreylevens]

Hmmm, maybe warmed and slightly IPA thinned epoxy to seal, then glass... Hate to run out mid way though... 2 1/2 hour plus, round trip plus something like $30 for more epoxy.

[geoffreylevens]

Just out of curiosity, don't they almost always paint surfboard foam w/ acrylic paint before glassing whenever they do art work on them?

[global ernie]

PU blanks are usually sprayed with thinned acrylic prior to glassing, even the white boards get a paint job, slows down the inevitable browning process. purely cosmetic just like whitening toothpaste

[geoffreylevens]

[global ernie]

all PU/ polyester boards start deteriorating from the moment of their "birth", you may have noticed the "starring" in the laminate on a new board. signs of continuing decay. the relative density of the foam plays a factor in this process but the quality of the reason matrix also contributes to the general deterioration. vinyl ester and epoxy resins are of course superior but the trad PU/polyester enables fast production if needed. i dont think that the paint job on PU boards serve as a sealer.
i will check with my mate later this week, he has built 10,000 + boards and prior to that fitted out trawlers/ yachts etc with all manner of materials
for 20 years.