Seems those in the know throw out terms as if we, who are starving to learn, are automatically in the know. So as not to bore everyone with another thread containing another boring simple question, I just spent the last two hours going through the archives trying to get a handle on what I assumed was an incredibly simple question. I’m now more confused than ever. I found everything…except the answer. I’ve seen the term “cheater coat” used relative to laminating glass over wood (balsa) boards. I’ve read the various “votes” for epoxy over lam resin, and visa-versa,etc. One of the pros (Paul Jensen) says that a cheater coat “is usually done after the board is laminated”, while the master (J. Phillips)states: cheater coating them once if not twice before glassing". So, could someone explain what is a cheater coat, and when do you apply it? I’m forever thankful for any information to clear this up!!
this should probably go in the glossary, which is in the resources area but never got finished: a CHEATER COAT is a layer of resin used to pre-treat wood (especially porous wood such as balsa) before lamination – this is necessary because without it the wood will absorb enough resin to prevent good lamination of the fiberglass cloth to the shaped wood blank (or stringer, or tailblock). I’m sure others can improve this…
Paul or anyone, I’m going to make a new set of keels from a piece of plywood teak. Do I seal them with epoxy before lam or can I use acrylic spray paint or sanding resin?
a cheater coat is also a layer of lam. resin over a cured lamanation before the hotcoat, usually done on the bottom of a board… it helps fill in the weave of the cloth and imperfections from the top lap and glassed on fins, it makes sanding easier, a good trick if your new to glassing. i use to make wood fins from exocitc woods and had huge problems with polyester resin sticking to some of the woods, i was told it was something to do with the styrene, so i started usings System 3 clear coat epoxy and had great results, and yes i would paint up the raw wood with a thin coat, let it cure and then beging laying on the glass… good luck…
in most of the posts here that’s been called “basting the laps” but referring to it as a cheater coat makes sense too…
Having worked on boats for years I can tell lots of horror stories about polyester over wood. One pin hole and you have tissue paper mush in short order. Polyester doesn’t bond well at all. A base coat (cheater coat) whatever you want to call it of epoxy that penetrates the pores of the wood, maybe two is the way to go. Then you can rough up the surface and give you self something that will be tremendously tough and durable by doing you fiberglass/epoxy lamination. It’s the only way to go. Mahalo, Rich
If its an oily wood plain old shellac will do better than anything.Porous woods such as Balsa need to be primed with the resin that you are going to glass with.Just keep on priming until it has an even wet sheen…if the balsa has dry spots it will suck up the resin making a poor bond.This is especially true on the end grain.Ever notice the wood nose and tail blocks on old redwood and balsa planks??Well that was not for looks…it was to block off end grain.End grain tends to split and absorbs water.