If you work with wood for any time at all, you’re going to end up getting polyurethane varnish on your hands. I try to use rubber gloves when staining and varnishing to avoid that. But there are times I have something small to varnish, so I don’t bother with the gloves.
Yeah, I end up varnishing my hands those times, or even worse, get wood stain on them, which is harder to get off. There are some water-based polyurethane varnishes on the market, manufactured by all the major manufacturers of wood finish.
These have been developed to reduce the VOCs (volatile organic compounds) that are produced by the varnish—in other words, the amount of chemicals that evaporate during the drying process.
They are sold as a direct replacement for oil-based varnishes, but I personally have my doubts about how effective they are. They tend to cost more, require more coats to achieve the same thickness of coverage, and are more prone to scratching.
The nice thing about those water-based polyurethane varnishes, at least from the viewpoint of what we’re discussing, is that they are easier to clean up. If you get them on your hands, all you have to do is wash them off with soap and water. The same goes for getting them off your tools.
But we’re not talking about water-based finishes here; we’re talking about the old standard, oil-based polyurethane varnish; the same finish that has been in use since it was invented in 1937. How do you get that off your hands, on the inevitable occasions that you end up getting it on your hands?
Method #1: Mineral Spirits
As an oil-based paint product, the best possible solvent and the solvent that is recommended on the MSDS (material safety data sheet) for polyurethane varnish is mineral spirits [1].
It is getting harder and harder to find mineral spirits in paint stores and home improvement centers because it is gradually being replaced by a product called “paint thinner.” Sometimes, the label says “Mineral Spirits Substitute.”
This is not mineral spirits, even though there was a time when mineral spirits was referred to as paint thinner. Rather, it is a water-based product that is supposed to do the same thing. But it doesn’t… at least, not as well.
Method #2: Denatured Alcohol
If you can’t find mineral spirits, then look for denatured alcohol, which should also be available. This is ethyl alcohol, the kind found in alcoholic beverages, which has additives that are either toxic or bad tasting, to keep alcoholics from drinking it.
Denatured alcohol is used as an industrial solvent for cleaning. It is an effective cleaning agent for oils and grease, due to its ability to dissolve them thoroughly. Since polyurethane varnish is oil-based, denatured alcohol is a good solvent for it.
Okay, but what happens if you are working on a project, using poly, and don’t realize that you don’t have any mineral spirits or denatured alcohol on hand until it’s too late? Your hands are sticky and your container of mineral spirits is empty.
Perhaps the lid wasn’t on tight and it evaporated. Whatever the reason, you still need to get your hands clean. What do you do?
Method #3: Cooking Oil
Go in the kitchen and grab some cooking oil. Yes, the same vegetable-based cooking oil that is used to fry food and bake cakes, will also serve as a solvent for pretty much any oil-based product, including you’re the varnish on your hands.
All oil-based products will mix, meaning that they will mix with that varnish on your hands. Then, all you have to do is use a little water and dish detergent to clean it off. Dishwashing liquid is better than hand soap in this instance, as it cuts through grease and oils better.
Since oil-based products mix with and dissolve other oil-based products, cooking oil isn’t the only thing you can use to clean polyurethane off your hands.
You can also use any other oil-based product, like peanut butter. That will probably leave your hands smelling better than the mineral spirits will anyway. You’ll still need to wash your hands afterward, but you won’t have that varnish there.
However, if you’re going to use dishwashing liquid to wash your hands, it’s going to remove the naturally occurring oil in your skin, drying your hands out. So, you might want to use hand lotion afterward, to protect the skin of your hands from cracking.
For that matter, both mineral spirits and denatured alcohol will remove the naturally occurring oil from your hands, even better than the dishwashing liquid will, so you should use hand lotion after those as well.
But what happens if you miss a spot? You’ve cleaned up from varnishing your latest woodworking project and you’re sitting in front of the TV, where you notice a spot of dried varnish on the back of your hands that you had missed.
Will the aforementioned solvents still remove it? Yes. But you don’t have to get up from your program to rush off and clean your hands again. Rather, since it’s already dry, just let it sit there till the next day. It will dry, become brittle, and flake off your hands in about a day.
Final Thoughts
While polyurethane varnish can be stubborn to remove from skin, there are several effective methods to get it off your hands. Mineral spirits or denatured alcohol are the ideal solvents, as they are designed to dissolve oil-based finishes. However, in a pinch, common household oils like cooking oils or even peanut butter can work by mixing with the varnish, allowing it to then be washed away with dish soap and water.
Regardless of the removal method, following up with a quality hand lotion will help replenish your skin’s natural oils and prevent cracking. With some know-how and basic supplies, woodworkers can keep their hands varnish-free.
Rich is a second-generation woodworker, having grown up in his dad’s workshop, “making sawdust.” Fifty years later, he’s still studying and working on improving his own woodworking skills, while also helping new woodworkers “catch the bug” for the smell of fresh sawdust. While Rich has done some custom woodworking projects, his greatest thrill is helping the next generation of woodworkers along, regardless of their age. His background as an engineer and a writer just adds to his ability to teach his true passion, woodworking.
