Conversion Varnish Dust Problems

Imperfections in a CV finish could be caused by dust, air, or problems in the sealer coat. Here, pros suggest fixes for each. December 1, 2005

I have recently started using conversion varnish, but it seems like no matter what I do, I have dust problems. Sand, wipe, blow, wipe, blow again. Even after all of this, as soon as I spray a coat on, it looks like I dropped a handful of sand in it. I am spraying with an air assisted airless. If anyone has ideas, please let me know.

Forum Responses
(Finishing Forum)
After you clean your spray area, you will still have dust in the air. Until this settles, you will always have this nightmare. What I do most times is clean the place before I go home at day's end. When you come in, in the morning you will see that the dust has settled. Tack off the dust from the piece to be sprayed and do your thing. This should solve the nightmare.

Also try an Ionix blow gun to help with some of the static. That may be part of the problem.

Be sure your spray equipment is grounded, as well.

I have a feeling what you are seeing is air entrapped in the finish. You will need to add some retarder and check your settings. I will let someone else pipe in here with the proper, if there is such a thing, setting they have good results with. As for the retarder to use, I have good luck adding about 5 ounces of hi-flash naptha per gallon of CV. As far as the settings go, try turning your fluid and air off. Point your gun at a piece of cardboard and slowly turn your fluid pressure up. You should see a large circle of material in the middle with smaller circles/dots on the top and bottom. Now start turning your air pressure up until all the dots connect. Then spray a sample board.

Are you using vinyl sealer under it? Or are you self sealing? I've had problems with the vinyl sealer acting just as you explained... not exactly wrinkling, but kind of. I used to shoot SW CV. Make sure they don't sell you on the pre-cat vinyl. Always go with the stuff you catalyze yourself before use.

Check to be sure it is catalyzed properly. How fast does it dry? If you spray another coat over it, does it wrinkle? I always spray SW CV straight out of the can, so any dust that gets on it is buried in the finish.

Are you sure it's not in your CV? Try straining finer and make sure.