I'm doing a project using 3/4" baltic birch ply. Because it will be exposed to ground moisture, dew, etc., and it must not warp at all, I want to encapsulate the whole thing in epoxy after it's assembled. The coating must be thick enough to hide all the wood grain and seams and whatnot; it must form a flat surface. After that, the epoxy will be sanded and painted black.
I found several kinds of epoxy by System Three:
One is called "general purpose", it's a thick amber liquid that looks like honey.
Another is called "mirror coat". They say it's "a pourable, self-leveling bar and tabletop coating."
The other is called "clear coat" and they say it's "an extremely low viscosity, water white, penetrating epoxy system."
Here's what I'm inclined to do, let me know what you think:
I'd rather use the clear epoxy. It's a bit more expensive than the other two but not by much (22% more than the generic). I don't care about transparency, I'm going to paint it over anyway. But I like the idea of working with a very watery resin, unless there are any hidden drawbacks that I'm not aware of.
Since it's very fluid, I imagine it will be better at hiding the grain and the seams, and it might be easier to spread it out to form a very flat and straight surface. They explicitly say it's "penetrating", which sounds good - I'd like to use a resin that gets soaked deep into the wood and penetrates all the little spaces and cracks. Unless I'm missing something obvious, it just sounds like a very good thing (if you ignore the price hike). Am I right?
Also, I assume I could use it instead of carpenter's glue, to assemble the various pieces. It's kind of a waste, to glue wood with the fancy clear resin, but if I'm buying it anyway, I may as well use it, right? The fact that it's watery should not be a problem, if I manage to get enough of it between the dado and the other piece.
I'm asking all these questions because I never used epoxy, so please let me know if I'm wrong.
Thanks.