PL 400
No pliers needed to pull this apart. The glue released from the lauan, and
pulled almost none of the wood apart. (Ignore the joint on the right side
that has some wood still on it, that was from another test.)
PL Concrete
This required pliers to get apart, but not as much force as the PL
Premium. The wood failed in a couple of spots, but the glue mostly just
pulled off of the wood. I only let this joint cure for 2 days though, and
the bottle says it should be allowed to cure for a week. I'm sure more
cure time would increase the strength.
PL Plus
No pliers required to get this joint apart. It took very little force to get it
apart. The glue readily released from the wood, and pulled none of the
wood apart.
PL Premium
This one required pliers to get it apart. The wood failed over about half
the joint, and the glue failed over the rest of the joint.
Final results (in ascending order of strength):
-PL Plus was basically worthless after a week in the water;
-PL 400 was slightly better than the PL Plus (but considerably weaker than before it soaked);
-PL concrete was slightly better still (but I didn't let this stuff cure for long enough to get accurate results);
-PL premium was weakened slightly by the water, but still remained strong enough to pull the wood apart.
PL 400
PL Concrete
PL Plus
PL Premium