Did my Andersen No-Sway WDH do this???

09KZMXT266 wrote:

How do you explain I dropped the trailer off with a perfectly good frame, and I picked it up with a damaged one. I didn't tow it home with the plate, so the plate could not have caused it on my 7 mile drive home. To be fair I only saw the hole after installing the plate and tightening the chain nuts. Maybe I should have titled the thread did installing the Andersen damage my trailer frame?

I'm guessing that the trailer only appeared to have a perfectly good frame when you dropped it off.
It is quite possible that, in the 2000 miles of towing, the horizontal friction force caused by the plate rubbing against the bottom of the weld bead resulted in cumulative low-cycle high-stress fatigue damage between bead and frame metal.

Certain aluminum alloys are know to be susceptible to stress corrosion cracking.
The microscopic cracking might have gotten worse over the winter due to humidity and other factors.

When you got the trailer home, it is quite possible that installing the plate and tightening the chain nuts caused 1) the rear of the plate to push upward against the bottom of the weld bead, and 2) the rear of the plate to rotate to the right.
The right-directed friction force acting on the bottom of the bead could have caused the final failure of the already-weakened weld.

So, I think it is quite possible that the 2000 miles of towing with the plate rubbing against the bottom of the bead weakened the weld,
and the installation of the plate after returning from storage was the "final straw" which caused the bead to separate from the frame metal.

Ron