I recently used Sherwin Williams Kemvar conversion varnish for the first time. I was drawn to the finish because the project was a solid 3x5 maple top for a kitchen. The shop is small Ė 3,000 square feet with an open face spray booth. There is no machining or sanding during this process, but thatís not to kid myself and think the air was pure. We have two air cleaners that hang down from ceiling trying to get some of the dust. The product is a very good product and the end results were ok. We had some defects in the finish. I concluded that our environment isn't conducive for this type of product to reach its maximum potential. What experiences have other people had with this product? Small shops in particular. Any insight would be appreciated.
From contributor A:
The air cleaners are probably part of the problem. You need to get the shop as dust free as possible. Start by removing the obvious debris with a broom. Spray fan should be as close to the floor as possible. Start at the back of the shop and use an air hose to spray the dust off of everything, including your hanging filters which are in the air stream. Blow it toward the fan, pushing it out. Leave the fan on for 30 minutes after you stop air hosing to let the remaining dust settle. You also need to consider where your makeup air is coming from. The window or door may be contributing to your problems. I doubt the finish is the issue. It sounds like a dusty environment.
Most seasoned finishers would likely cringe if they saw some of the shop conditions in which Iíve sprayed coatings, but keeping the spray area as clean as possible will help you achieve a fine finish. If dust in the finish is your main objection, police your area with a finer toothed comb. If cracking and crazing (the Kemvar curse) become an issue, they can easily be resolved with some additional heat in your spray area. Donít give up on the Kemvar, I think itís a good product.