Avoiding Orange-Peel with Conversion Varnish

Advice on adding measured amounts of thinner to achieve a proper spray consistency and prevent orange peel. February 15, 2009

Can anybody give me any tips on spraying white varnish? Can anyone tell me the perfect air pressure, amount of catalyzer, and etc.? I’m getting orange peel on the first coat.

Forum Responses
(Finishing Forum)
From contributor D:
Do you have experience in spraying C/V of any kind? You will need to follow the manufacturer’s specific ratio for the addition of catalyst to their product. All manufacturers have slightly different formulas and products, so without knowing which products you are using it is hard to give a specific ratio.

Once you have the required ratio it will take a few trials to tweak your gun for perfect spray. This will also depend on what type of equipment you are using. Airless, air-assisted airless, turbine HVLP, compressed converted HVLP? Specifics given will enable this forum to assist you more precisely.

From Paul Snyder, forum technical advisor:
Orange peel is orange peel no matter what you're spraying. The simple fix is always to add more thinner. It also helps if some of the thinner evaporates slowly (called retarder).

Catalyze a quart of the CV according to the manufacturer's guidelines. Then thin it 10% and see how it sprays. Add more thinner in 5% increments until it sprays nicely. Use the thinner and retarder that the manufacturer recommends to make sure it's 100% compatible.

CV is typically thick, with a high solids content for faster build. Generally two coats of CV will give you the equivalent build of three coats of lacquer. The extra thickness is a problem for a lot of spray equipment because it's more difficult to atomize and requires a little different spray technique (much heavier than you might be used to).

From contributor S:
Paul's advice is excellent. With an Airmix you can avoid the reduction but with conventional spray equipment you'll need to thin the CV. Each company uses a different reducer for the Valspar line that I use they recommend lacquer thinner. Others use Xylene.