Ok. Some results after a few hours of drying.
Keeping in mind this was 1 light coat. Recommended application is 2 light coats.
Test piece with silicone corner and smeared on the flat area before I started messing with it.
The paint has almost 0 adhesion to the silicone. Stuck to itself very well. Was easily pulled off with minimal effort.
After flexing the silicon corner hinge I made I noted that the paint stretches very well and shrinks back to it's original position. This is good if the tank flexes a bit.
But as with the flat piece, near 0 adhesion to the silicone corner
The 2nd test piece was just 2 pieces of plywood held together by hand while I painted them. The paint is a bit thin so it penetrated the joint. But did not adhere the pieces together at all. This makes me a bit nervous as I need to seal the joints now but will have to find something that the paint will stick to.
I applied a bead of silicone over the dried paint to see if silicone sill stick to the cured paint at all.
Will report back with findings.
If unsuccessful, I'll try sealing a corner test piece with fiberglass resin and a 2-4" strip of mat and let it cure. That will additionally strengthen my corners and hopefully the paint will stick to the cured resin. The benefit being I can rough up the resin with sand paper to help out.