Just remember to sand both the underside of the deck and the wood you're using. Yours might have failed because of blush. Normally a good epoxy joint is like a weld and won't fail. Stick with Pine, Spruce, Fir etc. Avoid Oily woods like purple heart, Oak, rosewood etc. Also make sure you use thickned epoxy to fill any discrepencies in the curvature of the underside of the deck.