Water based finish over Waterlox? Possible?

[Michael Donahue]

Hey folks. The weather in my neck of the woods has been brutal recently, and my basement/shop is hot and humid. I'm finishing some pieces for a bathroom with Waterlox and the whole process is driving me nuts! I know that the weather is anything but ideal, but the Waterlox is talking forever to dry and I can't get a good build after 3-4 coats. I've been getting alot of dust in the finish too so I'm at my wit's end. I'd like to make a spot in an air conditioned part of the house to finish up the finishing, and the heavy Waterlox fumes are not an option. If I move my pieces to a more climate controlled area to give the Waterlox some extra time to cure, is there a decent water-based finish that I can wipe or brush on to get the build I need?

Thanks for the help.

[Scott Holmes]

Are you using Waterlox Original?

If so, an easy way to apply it is to mix it 50/50 with mineral spirits (MS) and apply it as a wipe-on varnish. The best technique for wipe-on is to wipe it from a damp rag or pad, just get it damp like the kid that wipes the table at the fast food joint. It will dry to the touch in 45 minutes or so... repeat 2 more times, then give it a day to dry. Light sand if needed, wipe the sanding dust with a MS dampened rag and repeat the 3 coats per night. 3 wipe-on like this are about the same build as a properly applied brush on coat. 9 wipe on coats total should do well. If you want more build add a few more sets of 3 coats.

No sanding is needed between the wipe-on coats that are 45 minutes to an hour apart. The sanding after the overnight drying is to level the surface; it is not a must, if you use a non poly varnish.

[Jim Becker]

Please note that water borne finishes can also be sensitive to high humidity...remember, most, if not all, are "water borne" not "water based". That means there are still solvents involved with the acrylic resins so the finish can cure. The water is merely a carrier. That means you can be faced with both slow evaporation of the water that the finish is suspended in and the actual curing of the finish could be affected by the high humidity, too, including blushing.

Water borne finishes can sometimes be wiped on, but really can't handle much more than minimal thinning. The water is not the finish's solvent so when you add water, you're spreading out the finish molecules in suspension. At some point beyond about 10% thinning, the end result goes downhill fast in many cases.

[Howard Acheson]

>> Please note that water borne finishes can also be sensitive to high humidity.

Very true. Many manufacturers or waterborne finishes recommend it be used at below 85% relative humidity. Given that the first step in the drying and curing of waterborne finishes is the evaporation of the water, high humidity will significantly impede proper drying.