Adhesion Testing

OK, we've made our sample and are about ready to apply finish to our project. How do we know our finish schedule is good?  Will the finish peel off because we did something wrong? Luckily there is a simple way to find out. Do an adhesion test. If you want to be very precise and have and extra $270 to spend you could pick up the Gardco P-A-T Paint Adhesion Test Kit.  I am much cheaper than that and use a razor blade to score my finish and filament tape burnished to the cuts for the test. Not as accurate I guess but I just want to be sure I have good adhesion.

Here is the Classification Chart from Gardco to show the percentage of adhesion using their tool.

Metal inlays can be a problem on table tops and even 2K urethane doesn't adhere well as shown below.

 By simply using a good 2K isolante from Chemcraft I was able to get much better adhesion.

I just make sure to cut through to the substrate with the razor blade then

 burnish the filament tape down over the cuts and rip the tape off.

This is a good way to check on those glaze finishes as well to make sure the glaze has properly been done.