A few of the pros in the business responded a few days ago regarding “cheater coats” and “insurance coats” as a resin seal to insure bond of glass to balsa. Despite a few direct posted questions, I did not see an answer regarding the “recipe” or formula or even the deffinition of this process. So again, what is a cheater coat and what is the general recipe or formula? Thanks much!
A sealer coat is put on balsa and other woods if your using polyester. It is shot SLOWWWWWWW so the resin bonds better to the wood (less shrinkage). Then the board is laminated. A “cheater” coat is usually done after the board is laminated and shot hot on the gelled laminate to fill voids, or pin air, in the laminate. Epoxy does eliminate the need for sealing because epoxy is a more aggesive adhesive and has much less shrink during curing.
Howzit Greg, I was having problems with lamiming a nose repair ( whole front section) on 1 of my balsas, the lam kept delamming. I was going to coat the area with uncatalyzed resin and put it aside til it hardened ( takes about 2 weeks). But I decided to try some UV resin,it worked just fine. I think it kicked off so fast that the Oils in the wood didn’t have time to rise to the surface and cause another delam. Aloha, Kokua
When glassing my balsa, I also used UV resin. No sealer coat - just laminated as usual and put it in the sun. No problems yet on the balsa or redwood used on nose and tail blocks. It’s been 5 months and the board has seen hot temperatures, direct sun, etc and still holding up.
polyester direct to balsa is no go …if your gonna seal it with epoxy first then you might as well just laminate the whole board in epoxy or else you will have to sand the epoxy before applying the poly and thats more work if you want really good penetration bake the board first get it hot when the resin hits it will go really runny soaking deep and as the board cools it will suck the resin deeper…have fun regards BERT…
I have to agree with John and co. UV has changed everything with respect to polyester applied to wood. Great for tailblocks, fish fins, stubborn stringers, and all wooden boards… Perfect every time.