Priming with unthickend before fillets

I'm in the early stages of building the Tandem Wherry. Although it's not addressed in the manual , does it make sense to brush on a thin layer of unthickened epoxy before laying down the fillets? For that matter, how about a complete seal coat on the bare wood before fillets and glass?

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RE: Priming with unthickend before fillets

   No, that would just open you up to dripping and other problems.   It, fillets and glassing,  works fine without "priming".   


You'd do better to use your extra coat of epoxy when filling the weave. 

RE: Priming with unthickend before fillets

FWIW, I always put a coating of unthickened epoxy onto joints, especially the endgrain portions, before filleting. This is to avoid "dry" joints where the epoxy/woodflour putty doesn't contain enough liquid to properly saturate and/or bond to the wood. I avoid dripping by careful application.

But I don't feel the need to pre-coat the entire boat before glassing, just the joints. I've been able to get my lay-up technique to where I don't need to do it in 2 steps. It doesn't hurt to precoat, it's just an extra step that I prefer to skip.


RE: Priming with unthickend before fillets

   "Epoxy Basics" book I ordered says the strongest joint is with unthickened coated to ensure grain saturated and then filleting on top of that. It's not a thick drippy layer just to ensure the grain soaks up the epoxy and bonds really well with the fillet.  This isn't done in the classes or at least the class I took the focus is more on the right fillet consistency but after reading the book I did use this for my mast, I mixed two cups of epoxy, one thickened with silica and one unthicked since that joint goes through a lot of stress and is so important.

Here is a guide from CLCs own employee doing the same for the fillets:

"“Priming” the joints with epoxy that has not been thickened, coats all of the surfaces of the interior of the joint and and soaks more deeply into the wood than thickened epoxy, creating a stronger bond. It also lubricates the surfaces, making it easier to get the thickened epoxy all the way into the joint, making it less likely that there will be any voids. "

It's probably not necessary and most people skip it, but it is supposed to be stronger

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