Conversion Varnish Application Basics

A first-timer gets tips on applying conversion varnish, compared to the nitrocellulose laquer he's used to. December 1, 2005

Question
I'm getting ready to try my first tinted conversion varnish project and I would appreciate any suggestions. I have sprayed a lot of nitro-cellulose and I think I'm going with a 1.4 needle and 1 gallon pressure pot setup.

Forum Responses
(Finishing Forum)
Make absolutely sure your equipment is clean, as nitrocellulose is not compatible with conversion varnish and will cause the varnish to gel or plug up your gun, hoses, tips, etc. Depending upon who makes it, you can thin with Toluene, Xylene for a little slower dry time, but some varnishes you can thin with lacquer thinner, although I highly recommend a good quality thinner to reduce the chances of high moisture content in the thinner. I don't know about your spraying experience with conversion varnish, but they dry about the same as regular lacquer but do not re-wet themselves like lacquer does, therefore, when you sand between coats, remove the dust so it will not melt back in. Check with the manufacturer of the varnish to be sure about thinning and recommended dry film thickness.

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Proper shop temperature is also critical. If you can, store the project in a safe, well-ventilated area while the project is curing (gassing off). Another thing to consider is the mill thickness of a CV - it's more critical in a catalyzed finish than, say, a conventional lacquer coating. Last but not least is a well fitting, properly maintained respirator. Formaldehyde and Isocyanides are some mean stuff, so take caution. Keep your hands real clean, too.