I just came across a video where a guy tested the adhesion of filler applied to epoxy vs bare metal. I was planning on applying filler over epoxy as most people recommend on this forum but this video has me weighing the pro & cons of each process. In the video the bond between bare metal and the filler is stronger but it's not that simple. He tests the bond by sandwiching three washers together, on one side of the middle washer the filler is applied on bare metal, the other side is between two coats of epoxy. When he pulls them apart the epoxy side separates first. But wait teh interesting thing is the filler didn't release from the epoxy, the epoxy split leaving epoxy stuck to the filled and the washer. The force required to separate the bare washers is significantly stronger than the epoxy side. Now I am really confused. Living in southern CA I am not to worried about the filler absorbing moisture before I seal it with epoxy.
I know there are some variables like how long was the epoxy cured, how was the surface preped. But the weird thing is the epoxy must have bonded pretty well with both the filler and the metal because it does not pull of either surface, It actually splits.
Any thoughts?
Here is the video:
I know there are some variables like how long was the epoxy cured, how was the surface preped. But the weird thing is the epoxy must have bonded pretty well with both the filler and the metal because it does not pull of either surface, It actually splits.
Any thoughts?
Here is the video: