Masking and Tenting for Spraying in a House

A finisher contemplating using his HVLP gun in a customer's house gets advice on explosion and fire risks, tips for protecting the furniture, and suggestions for switching to waterborne products. January 29, 2009

I need to paint a 12' section of wainscot I installed in a customer’s house. Overspray is my only concern. I want to use a turbine hvlp system if possible. I don't have any experience with an hvlp system. Is there enough overspray that I would need to quarantine the area with plastic drop clothes, sort of like a tent, to avoid over spray? Is it possible to spray with only certain areas masked off? In other words, how much overspray is there with an hvlp system?

Forum Responses
(Finishing Forum)
From contributor B:
There’s enough to be concerned with overspray. You still need to mask off. You didn't say what kind of product you will be using.

From the original questioner:
I will be using Sherwin Williams Pro. oil base. I thought I could just cover the floor in the immediate area, mask surrounding walls and cover a couple pieces of furniture. I just didn't know how much overspray there would be. I'm not a finisher by trade but I have painted a few interiors of new construction with airless.

From contributor S:
Since it’s in a client’s home I would treat it like drywall dust - quarantine the area. Also, since you’re using oil based have you thought about ventilation and a day or two curing time for the gases to subside? Just from experience I would make them aware of this or just use a good water-borne enamel. SW All Surface Enamel is good, but requires a lot of thinning. Or better yet Benjamin Moore's Impervo water borne enamel requires no thinning and spray's really well through a turbine.

From contributor D:
If this is an occupied house I would go with a water base finish due to fire hazard. Twenty years ago I was troweling mastic on a wall for laminate wall splashes and it "flashed". In the next room was a gas dryer that ignited the fumes. I carry a fire extinguisher with me when using anything flammable.

From contributor P:
Mask off and cover absolutely everything in the room and ventilate. The explosion hazard is real and consideration should be made. It'll smell like hell for a while after your done (days), so make sure the homeowner knows what to expect. SW makes a Proclassic waterbased. It's a good finish and it doesn't yellow like oil. Ben Moore paints are also very good.

From contributor T:
I finished a four flight staircase with stain and four coats of poly using an HVLP. The overspray (enough to need masking and plastic sheeting) was all contained in a tent that quarantined the area from the rest of the finished house. I used an exhaust fan at one end and an opened window at the other end to provide fresh ventilation. Turn off all sources of ignition and locate your turbine outside the work area.

From contributor L:
I would suggest that you go waterborne simply for safety. If you’re spraying then there will be overspray so cover all your bases. It can cost you if you don't. Speaking from experience, I learned the hard way, you don't have to.

From contributor A:
I would recommend you consider changing your strategy, simplify by changing your product. Huge hassle with the route you are planning.

For only 12' of wainscot to paint, why not just brush it. Muralo Ultra is waterbased, close to zero oder, and will lay out and look like it was sprayed. Mask off the edges around your wainscot, lay down a drop cloth on the floor and begin. Prime first with their waterbased Universal Primer and lightly sand between coats.

From contributor K:
If you have not used an HVLP before, be aware you can cut your overspray dramatically by adjusting your air/material mix. If you are spraying too much material you will notice you also have a lot of overspray (as I did). I mainly spray waterborne poly. If I adjust the air all the way up and the material down until the point at which it just atomizes nicely you should not have much overspray. More thin coats. You can adjust the air but latex usually requires all the air it can get.