So i just tried the same for the first time and also had my first failure. I've been having fits w/ my aftermarket tail light housings..mainly because it's a challenge to weld into the upper inside of the inner quarter and see what you're doing with a welding helmet on. after having a first fail at welding, i tried my tube of 3M 08115.
Fresh tube, followed directions, removed e-coat, cleaned bare metal, allowed it to dry, squeezed it on, clamped and waited almost 24hrs. I removed the clamps today, nudged it and it fell off w/ minimal force.
I even went as far as to weld on an additional lip to my out of square tail light housing to reduce the force & twist on it from the original weld.
I'm sure I screwed something up, but am gun shy to use it on anything else. This is typically where the forum would chastise the person that they didn't follow the MSD, etc. I'd like to learn from this experience however?
Has anyone else experienced this? It looks like the adhesive stuck to the metal, but allowed itself to split apart? It doesn't seem to have hardened as much as I expected after 24hrs. I had it in my shop at around 60 degrees for 24hrs.