Cleaning Oil-Based Enamel Paint Overspray Off Conversion Varnish

Clay bar or a mild solvent is recommended for removing paint overspray from a CV finish. February 12, 2010

I recently discovered that the on-site painter oversprayed oil base enamel paint over my conversion varnish. What chemical can I use to remove the overspray without damaging the CV?

Forum Responses
(Finishing Forum)
From contributor B:
If the overspray is fairly light and recent, I would use furniture oil and pumice. It may require a moderate amount of elbow grease but it won't do anything to the finish except polish it.

From contributor R:
Try some H2o and a clay bar. The clay won't change the sheen of the conversion varnish.

From the original questioner:
Thanks. Can I pick up a clay bar at an arts and crafts store? And do I wet the surface and then rub the clay over the area?

From contributor R:
Your best bet for the clay bar is your local auto parts house. You can get a kit made by Mothers with a small clay bar, some bar solution and wax.

Since you're going to be removing a bit of overspray and not trying to remove tar or road grime from an automobile surface, I would just use the bar and save the solution and the wax for the car. Just dip the clay bar in some water and lightly move it over the surface. You don't need a whole lot of muscle, just enough to skim over the overspray. You could - if you want - put a little dish soap in the water to act like a lubricant. Don't be confused by the looks of the clay bar. Once you've used it, you will keep one in your touch up kit. You will have to decide on the pressure needed to remove the overspray; just keep the bar moistened with the water and you should be fine.

From contributor D:
Wait a couple of days and wipe off the enamel with lacquer thinner. That will work if what you sprayed is a decent quality conversion varnish. Your rag should be damp and almost wet with thinner, not soaked. Why is it your problem to do this and not the painter's problem?

From contributor U:
I was thinking lacquer thinner also, just a damp rag. I would think that any rubbing compound would tend to polish and increase the sheen.

From the original questioner:
I have to deal with it because I'm afraid these idiots will cause more damage. I'm doing damage control on some of their exterior fiascos also.

From contributor R:
The clay bar is so easy to use and it won't change the sheen of the coating. It also won't leave the room smelling of solvents.

From the original questioner:
Thanks. I will definitely try the clay first.

From contributor A:
How does the clay bar work?

From contributor R:
It is a block of clay that has super fine particles of abrasives incorporated into it. The auto industry has used these for many moons to remove overspray.

From contributor A:
How does an abrasive (no matter how fine) not change the sheen of a finish? If it is high gloss it will dull it. If it is semi-gloss the clay will shine it. You should be able to take a non-aggressive solvent and clean up the oil based without damaging the CV. I think I would try naphtha before lacquer thinner. CV is supposed to be resistant to lacquer thinner, but why risk it.

From contributor R:
Think of one shot of booze poured into a gallon of water - it's still booze. Think of one pint of sealer poured into a gallon of thinners - it's still sealer. Think of a single grain of grit engulfed into a brick of clay - it's still grit. It's all in the PPM - just enough to make a difference but not enough to lose sleep over.

From contributor L:
The clay bars have saved many a paint job. Good enough for cars, good enough for cabinets. If the oil is fresh, mineral spirits/naphtha will take it off, and will probably be the quickest.

From contributor S:
Before breaking out the liquids you could also try removal with tape. Rub it down well and pull it off. As long as your CV had a head start cure before the overspray, there is a good chance it will lift right off. Try both duct tape and the clear packaging tape.

From contributor J:
The clay bar will work but it's sort of a difficult solution to an easy problem. Since the conversion varnish is much more chemically resistant (assuming it's fully cured) than the oil based enamel is, the fix is as easy as removing the oil based overspray with a solvent that is strong enough to attack the oil based but not the conversion varnish. As usual start with a mild solvent such as mineral spirits and work your way up to stronger solvents until you find the one that works best.