Air Bubbles in Mirror Coat

[ericlkoehler]

I decided to use the mirror coat by System Three for my bar top epoxy coating. I have completed the first coat, which I made very thin. Just thick enough to seal off the wood. I believe that there are small air bubbles that formed, it is hard to tell if they are craters or air bubbles. So what type of sandpaper should I use to get out the air bubbles? Then what should I use to clean the surface before adding the next layer? Is the sandpaper going to scuff or scratch the surface, and will this show up thru the next layer?

Thanks!

[Dave W]

[Joe Brophy]

Use about 220 grit on the first coat then apply 2nd coat, while it is curing use a heat gun or other heat source to (carefully) heat the wet surface without burning it. The heat will allow the bubbles to rise through the uncured liquid coating faster because the resin looses viscosity as it's temp increases. Any stubborn bubbles can usually be fixed by popping them with a pin after heating the area around them first. Tap plastics has a good set of instructions for using this type of finish. Since most of these products use a form of epoxy the UV resistance is poor compared to other polymer coating like polyurethane and poly/vynilester resin products.

I use progressively finer grits on the orbital between each successive coat, leaving final coat un sanded. I built a kitchen table 28 years ago and it is still in good shape with only a few small scratches in spite of numerous moves to other regions of USA. I will likely re sand surface and re coat this year which will make it like new.

Joe