I do not believe there is one best finish. It all depends on the material you are working on, the end results, weather , your skill level ect. The reason I use the Seal Cell is to keep the weight down. It keeps large amounts of resin from soaking into the wood. I use it on balsa and western red cedar. On red wood if it is old growth I would not use it. If the redwood contains sapwood I would use it. For a good finish a sealer coat of resin is a good idea. It is really a filler coat (much like useing a past filler on open pore woods). Yes it will work if you thin it with DA as Paul does, Yes it will work if you do not thin it. If you use a slow hardener more will be absorbed into the wood and your board will be heaver. Fast hardener will mean less weight. Thining with DA will mean deeper penetration and as the DA evaporates off the wood pores will not be completely filled . The resin is spread on and allowed to soak and then squigeed off leaving no surface coat. Bubbles can also be caused by over working the resin. The resin should always be allowed to soak into the cloth. If you work it into the cloth with a squigee you cause it to froth (air bubbles!) A roller works on the fill coat on wood but does not work well on the cloth. I use a metal roler that is made for epoxy resin . Still let the resin soak into the cloth by itself. The squigee is used to take off the excess. If you scrap off to much you will end up with pin air or bubbles under the glass. Depending on the weather it is easier to learn epoxy by useing a slow hardener. I find it much easier than doing polyester resin. Fin boxes are installed after the glass is laminated but before the fill coat. Surfding, Yes I do use curley koa.. I make my living making koa furniture. All koa is expensive now. If you want koa (curley) you can get it from Winkler in Honolulu . Because of the rapid incress in koa prices my rocking chairs are selling at $3,500. Gotwood, I recomend that you go to the West system web and epoxy work for the best info on working with epoxy resin. Ahui Hou - Wood_Ogre
The furniture in my house that I made is all assembled with West Marine. Paduk and Black Ebony Slab. Great stuff. I think that I met you on Kauai years ago? Do you have a woodshop with an attached showroom? Lots of Curly Koa? You showed me your shop? Did you go to woodworking school on the East Coast?
I have 3 balsawood boards I need to finish. I will try your method and check it out. My Redwood board is old growth from about 400 years ago they say? So I will just paste with Poly then glass. I'm going to just hang this one in my house. 9'6" Dora with a matching Dora Fin in the same wood.
I want to make a 8'0 Sunset Gun out of all Curly Koa. Maybe before I died? You may have already done it?