Are all epoxy resins the same, and the difference only in the hardener? I ask because I found at the NAPA Auto Parts store some cheap epoxy, like a can of Bondo Fiberglass Resin, pretty cheap at $17 a quart. The same quantity of MAS epoxy is considerably more. Dunno why MAS is so much pricier than two years ago, but it is. Now these NAPA resins come with a tiny tube of hardener which hardens in 10 minutes, much too fast, and doubtless they all blush like the dickens (I nearly said like Doris Day in a porn film but the image is too off-putting). I wonder if I could use a MAS hardener with NAPA epoxy, and cut costs. Anybody tried mix n' matching like that? This is for sealing the wood of a Newfoundland paddle before varnishing. Even the cheapest CLC "economy kit" of MAS products way exceeds the cost of the paddle.