Dirty solvent waste can be a problem to get rid of. Even if you use water-based finishes, you’ll probably still accumulate some dirty solvents over time, from cleaning if nothing else. The best solution is to take the waste to a local hazardous-waste collection center, but these are not always conveniently available or even available at all.
For these situations, here are three suggestions for getting rid of the solvent waste.
- If you don’t have an excessive amount, pour it into gallon cans and let it sit without a lid. The solvents will slowly evaporate, leaving only solids, which you can safely throw in the trash when fully hardened. Be sure to wall off these cans from children and pets.
- Spray the solvent into the outside air, unless local laws forbid this. The solvent is going to evaporate anyway, but doing this is still illegal in some localities. You could also spray through a spray booth, which is actually no different than spraying a finish that contains the solvents.
- Pour the solvent onto a concrete driveway on a warm sunny day. The solvent will evaporate into the air quite quickly, but doing this is actually the most likely to be illegal in some localities. So check before doing it.
Even while I was operating a full-time, one-man refinishing shop, I was still able to use the first method with good success. The solvents evaporate slowly enough so I was never able to smell them in the air.
Your situation could be different, however, if you’re working in a small, very tight, enclosed space. So try it and see.
– Bob Flexner