Yes, i bet that's your problem, resin blush in cold and humidity. Go with filler on tacky lam to avoid it. Water wash and sand all shiny when you have to cover Harden resin. A hot box would be a must too. And if you can use addF from resin research, it's firstly make to avoid blush and work very well.
3:5 is a weird ratio, I imagine it would be easy to screw up, especially if mixed by volume in mixing cups that say its graduations are generally accurate.
Looks like an Epoxy to avoid though, whatever it is and another '+1' for not using non surfboard specific epoxies on surfboard laminations, whenever possible.
I'm using a more budget friendly surfboard epoxy easily acquired locally, that is not without its issues in regards to fisheyes and formation of blush, and is likely also bad in the yellowing department, if I ever glassed anything white. It will be my last batch of this brand, and I am inventing uses for it where its poor qualities will not be an issue to use it up faster to get something better the next go around.
Hi Lemat; may be is the different languages but I mentioned 2 times that the problem was with the filler coat. I applied the filler coat onto an stratification that filler coat peelled off. You laminate a surface (resin + fibers) and there is no way to see that blush...
---Yes; 5:3 is strange. You know; 10 parts an 6 parts. Possibly a generic pourpose resin. Made in Korea. No R R or similar here. Last time I worked with epoxy was in the late 80s. I do not see any improvement if you do not use wood, PS etc. Also you need to have the right room and conditions.
Sometimes you cannot have the controlled room due to you are working on stuff that are outside or in a big building etc.
Yes i understand fill coat Peel off lam. It's because resin of lam blush so no new coat over can glue. Blush appear while resin became hard when it became no more tacky. It's sometimes difficult to see it specially on lam because of fiber texture. That's heppened every batch of resin, no more with modern blush free epoxy. Fill coat on tacky lam before lam resin blush is one way to avoid filler peel off. Other way is to use a Peel ply as last layer of lam process so when you peel off blush with ply. Or you can water scuff Harden lam to remove blush. Last trick is to use addF.
Hi Lemat; did not thought that peeling off a layer of the stratification could be good for a blush situation.
I don't understand well, my english is realy basic...
Blush is a contamination of surface, works like when you put wax in mold to make parts.
One day i saw big adhesion problems when sytem that take off oil of air compressor fail. They use it to clean surface before lam, catastrophic...
Blush was a realy often problem when no blush resin was use. Epoxy board builder i know Always use the Gougeon's (west système) protocole : clean lam with water and scuffer, dry, sand then you can cover with resin.
When i start work with epoxy in 1989 i learn blush hard way, then i do this protocle each time. With blush free resin i stop it except if i have a doubt even if i work in regulate temp and humidity space.