3M 560 Urethane adhesive/sealant. This is impressive stuff. After glueing the two 1x4's together, I let it set 24 hours, then laid it on it's side and stood all 210 lbs. of me on top. After bouncing on it several times I cracked the boards but did not break the boards. The Urethane is still holding on just fine.
Picture Added 08-21-2009 02:04 AM Added by rrhatbruce
