Spraying Sealcoat Shellac in Basement Shop

[Jason Clary]

I've been starting to spray some waterbased stains, lacquer and poly but I haven't yet sprayed any Shellac. Is Sealcoat Shellac safe to spray in a basement workshop? Can it be sprayed by itself? Can it be sprayed when thinned with DNA? Basement has typical HVAC, Water Heater, Washer Dryer, etc. I've googled but couldn't find a definitive answer. Any help is appreciated.

[John Coloccia]

I've been starting to spray some waterbased stains, lacquer and poly but I haven't yet sprayed any Shellac. Is Sealcoat Shellac safe to spray in a basement workshop? Can it be sprayed by itself? Can it be sprayed when thinned with DNA? Basement has typical HVAC, Water Heater, Washer Dryer, etc. I've googled but couldn't find a definitive answer. Any help is appreciated.

The definitive answer is no.

It can be thinned with DNA. I like to spray about a .75# cut....maybe 1#.

[John TenEyck]

I believe alcohol will support combustion at about 11% vol. in air. You would probably pass out before you got to that concentration so, technically, you probably could spray it in your basement shop but I wouldn't do it. Even w/o the fire risk, it will get all over everything and make a general mess. However, all is not lost, read on.

I spray shellac all the time in my basement shop, but I do it inside a temporary spray booth that is vented outside. I use my dust collector fan (bypass the bags) as the exhaust fan and it works great. The 6x8 ft "booth" is nothing more than 6 mil plastic hung from the floor joists, with old bedsheets on the floor. The inlet hose from the 1100 cfm DC fan is in the back of the booth about waist high, and the outlet hose goes out a nearby window. I spray shellac and WB w/o any problems, but I do not spray other solvent based products. I don't use any filters because they just get coated over; however, nothing deposits on the fan or fan housing because the particles are dry before they get there and blows harmlessly outside.

This arrangement allows me to spray year round in my shop, a huge advantage for anyone who lives in a cold climate. My basement is heated in the Winter and I run a dehumidifier in the Summer, so I have near constant temp./humidity year round which takes a lot of the (mis)adventure out of spray finishing. The exhaust fan removes all overspray and smell during spraying; the only smell afterwards comes from the subsequent drying and curing of the finish. With shellac and WB products it's very acceptable to me and my wife. I turn off my furnace while spraying because some of the makeup air comes down the chimney. Even spraying for an hour in the dead of Winter only lowers the temp. in my shop a degree or two.

John

[Howard Acheson]

No finish can be safely sprayed (other than waterbornes) where there are sources of flames or sparks. Oil based poly, lacquer, shellac are all flammable and should only be spraying in proper spray booth or outdoors.

Another issue with spaying oil based finishes is that they are very slow drying. This means that the over spray is in the form of liquid droplets. These droplets float in the air and will land on any surfaces or items in the area leaving a hard crust on everything. Again, spray only in a proper spray booth or outdoors.

[John TenEyck]

Howard, I don't think the OP asked about spraying OB products; however, your comments certainly are worth noting. As for spraying shellac indoors, I'm not advocating that anyone else should do what I do, only that what I do works and is, in my opinion, safe to do with my setup. Certainly, a properly outfitted spray booth pretty much guarantees one's safety, but not many people can afford to have one in their basement shop. As such, we each have to decide for ourselves what's appropriate and what level of risk we accept with our actions.

John

[Jamie Buxton]

Target makes a waterborne shellac, designed for spraying. No alcohol to explode or get you high. http://www.targetcoatings.com/products/sealers-primers-a-grain-fillers/ultraseal-wb-shellac-sealer.html

[Howard Acheson]

Who's to know what the OP is referring to when he says "I've been starting to spray some waterbased stains, lacquer and poly but I haven't yet sprayed any Shellac". Why assume that the "lacquer" and "poly" is actually a mis-named waterborne acrylic finish? To me, in the context of the question, I assumed solvent based finishes for lacquer, shellac and poly. His specific reference is to a true alcohol based shellac (Seal Coat) so I assumed he was referring to solvent based finishers.

I formulated a response that provided enough info that the OP could use whatever part of it applied to his situation.

[Alan Lightstone]

I spray shellac all the time, but it's in a garage workshop with an explosion proof fan vented outside.

I wouldn't do it in a basement, unless you had a temporary spray booth, and an explosion proof fan venting outside (those fans are very expensive).