Closed Grain Finish

A finisher needs an efficient way to fill grain for spray finishes on exotic veneers. Suggestions include grain filler and an innovative mixing setup for his spray equipment. April 30, 2006

We use a Kremlin airmix system with Milesi catalyzed polyurethane. We do custom work with different exotic veneers (Koa, Makore, avodire, teak, sycamore, etimoe, macassar ebony, madrone burl, etc.) and on most of our projects, we are asked to do a closed grain finish. In order to do that with our sealer, we have to apply 3-5 coats to get there, depending on the essence. We are looking to accelerate the process as our paint shop becomes more and more a bottleneck in the shop. We did try polyester, but don't feel comfortable working with all the chemicals involved. Any advice? Any sealer out there with better grain closing ?

Forum Responses
(Finishing Forum)
From contributor M:
Have you tried catalyzed sealers?

From contributor B:
They make grain filler. You simply apply this stuff to the wood, wipe it off, then wait a day and proceed with your finish. It saves a lot of hassle and makes for a great finish. We buy natural color filler - it's a light tan color. Then, depending on the color of the wood and stain we plan on using, we simply add stain to the batch of filler to get it the correct/custom filler color. We use Mohawk products, filler, stain, etc.

From contributor S:
Since you use a 2pk urethane, your best option is the polyester if you're looking for a spray filler. If you were able to use a conversion varnish or a post cat lacquer, your options are many.

From contributor T:
You said you were uncomfortable mixing the components with polys. I assume that's because it is 3 component, using cobalt and peroxide as catalyst, which are dangerous when mixed together undiluted. I have used a system that makes it very easy. I have taken a double diagram pump and modified the inlet in such a way that each side of the pump is sucking from a separate inlet and pumping into one outlet (to your gun). On the outlet, put a static mixer inline (this will mix the coating about two million times in a 10" span of tubing without moving - they're fairly inexpensive). Then pour your poly into separate material supply containers (A and B). Put the cobalt into A, and the peroxide into B. Your pump will now suck from both supplies and mix them together as you spray. Pretty simple once you do it... and no danger of the cobalt and peroxide mixing undiluted together.