Re: RESIN COST/QUALITY/DIFFERENCE
In my experience over the past 30 years, resin is very similar if not identical between name brands. <br />Buying a name brand often does bring better after sale customer support, but very little in product quality.<br /><br />A few of the sources I've used with good results are:<br /><br />Marine Epoxy - (Bateau Boatbuilders)<br />
http://boatbuildercentral.com/categories.php?id=2 <br /><br />Mr Fiberglass-Polyester Resins<br />
http://www.mrfiberglass.com/polyester_resins.html <br /><br />JGreer.com - Epoxy Resin & Mold Supplies<br />
http://jgreer.com/ <br /><br />They state publicly that their product is the same as the West System which has apparently become some sort of sales standard and all are much less expensive.<br /><br />To just bond two sheets of ply, it's not absolutely necessary to use a filler, but I do recommend that you do.<br /><br />On Ply, I use the wood dust I collect out of my orbital sander bag to mix in after having combined the resin and acelerator to a slightly less thin than peanut butter consistency. For wood, you can use, however, nearly any powder/fine granule from kitchen baking flour to talcum as well as the commercially available Aerocil or Cabocil, both of which are cheap to buy and available at all the sources I've listed.<br /><br />One advantage to using fine sawdust is that you acheive a wood color to start with. <br /><br />First, do your mixing in a larger area container than a cup. Or, if you mix in a cup, pour it into a larger flat container to give more surface area.<br /><br />During cure, epoxy generates it's own heat as it becomes, first, thinner, then quickly starts to set. In a cup, it will generate enough heat to speed up the setting process and reduce your working time. More surface area allows the heat to bleed off thereby extending your working time.<br /><br />I'd recommend first coating each ply with unfilled epoxy, then follow that immediately with a filled epoxy coat and clamp the pieces together for curing. The plain epoxy fills the wood pores and grabs the "tooth" of the grain. The filled epoxy ensures that all dips, dents and curves are in total contact on both pieces.<br /><br />Don't clamp them so firmly, however, that you squeeze out lots of epoxy. Epoxy is a great gap filler and needs a thin, but existent film to acheive best adhesion. If possible, I lay the pieces down, clamp the edges at 1 foot intervals and put my hand carry toobox in the center.
<br /><br />The epoxy "How To" at Bateau Boat builders and plans is a pretty complete and accurate treatise on best methods and materials.<br /><br />Good luck ...
