Venting spray booth

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Forum topic by GNMG posted 05-17-2017 12:50 PM 883 views 0 times favorited 10 replies Add to Favorites Watch
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8 posts in 980 days

05-17-2017 12:50 PM

Topic tags/keywords: question finishing spray gun

Hi folks,

For the first time, I will be finishing a dresser I built with an HVLP system. I precticed and am comfortsble with the process but I need to ensure dust control. I will be setting up a temporary spray booth in order to reduce dust. It will be a simple setup with a blower/fan with filter and thick plastic or card board dropped from the ceilling. My shop is small at 12×16. My unfinished side of the basement is roughly 12×57 and divised in 3 rooms. At each end, I have a small window. The one in my workshop will be the exhaust from the spray booth. Should I keep the shop door closed? Should I open the door of the shop to open it up with the other rooms? Should I open the door and the other window at the ither end of the house? I feel like ooening the other window will create a better flow and imofive reusults but I’m nit sure. The fan is 1200 CFM on high but also has low and medium speeds(the CFM rating is only indicated for high). I will also use other precautions in regards to dust control. Thanks a bunch!!

10 replies so far

View Rich's profile (online now)


5136 posts in 1193 days

#1 posted 05-17-2017 02:33 PM

You don’t mention what you are spraying, but if it’s flammable, your biggest concern should be explosion and fire, not dust. That’s why real spray booths use explosion-proof fans, and they are very expensive. If it’s possible to spray in an open area outside the basement, I think it will be safer for you.

If it’s a water borne product, you’re good.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View pintodeluxe's profile


6033 posts in 3417 days

#2 posted 05-17-2017 04:06 PM

1+ it depends on what you’re spraying, but good ventilation is a must. You can heat the area up before spraying, then turn off any heat source or anything with an open flame. Then open the doors and start the fans. You don’t want wind blowing into the workspace (could kick up dust), so you may have to open one door only partially.

Use a respirator no matter what finish you spray. Waterborne only means it’s water soluble, doesn’t mean it’s safe to drink!

Good luck. Once you spray, you will never go back to a brush or rag.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View GNMG's profile


8 posts in 980 days

#3 posted 05-17-2017 05:03 PM

I forgot to mention, I’m spraying a waterborne finish for that reason. I’m using Minwax Polycrylic.

How do you guys clean your spray guns for storage after a waterborne product? I dont intend to spray anything but waterborne out of it.

View ClammyBallz's profile


449 posts in 1741 days

#4 posted 05-17-2017 05:10 PM

The only thing you need to clean the gun with is water.

The room will have to be free of dust. Cover the doorway with an old sheet to let air in but block the dust. Blow the fan out the window.

View TungOil's profile (online now)


1371 posts in 1099 days

#5 posted 05-17-2017 06:04 PM

+++1 on advice above.

Is Minwax Polycrylic sprayable? Last time I looked at using it their tech guys told me not to spray it.

When I spray, I typically spray lacquer. Since it’s solvent based and I don’t have access to a proper spray booth any more, I usually wait for a nice day and spray outside. It dries fast and is really forgiving so I can usually get away with it. Not idea if you have a lot of bugs however.

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View pontic's profile


716 posts in 1213 days

#6 posted 05-17-2017 07:34 PM

They make Pneumatic fans. Oh wait they are one type of those expensive explosion proof fans.

-- Illigitimii non carburundum sum

View hotbyte's profile


1001 posts in 3580 days

#7 posted 05-17-2017 07:55 PM

I’ve sprayed straight polycrylic in my Earlex 5500 and it worked fine for me.

I don’t have a good place to clean gun in/near shop so I bring gun into kitchen. I pour excess material into a sealable jar and then rinse it a few time in hot water. I then add a little dish wash liquid and fill with hot water to soak while I put attention to gun itself.

For cleaning gun, I bought a small hand-held pump up sprayer from Ace. A little modification to the tip and I was able to connect a piece of hose from it to pickup tube on gun. If I will be spraying in next day or two, I’ll fill pump sprayer with a little soap and water, pump up and spray through gun. Then, I’ll follow with a sprayer full of water only. If I’ve completed project and no spraying for a while, I will then break apart gun (remove needle/tip, etc) and wash those with soapy warm water.

A few times, I left entire gun/cup into a 2 gallon zip lock bag in fridge overnight for spraying next day. We do same with brushes and roller covers.

View hotbyte's profile


1001 posts in 3580 days

#8 posted 05-17-2017 07:57 PM

This! I didn’t wear one first few times I sprayed and did not like smell/taste/breathing. I’ve started using respiratory and it makes spraying much more tolerable.

Use a respirator no matter what finish you spray. Waterborne only means it s water soluble, doesn t mean it s safe to drink!

- pintodeluxe

View AandCstyle's profile


3262 posts in 2861 days

#9 posted 05-17-2017 09:32 PM

GNMG, I exhaust my spray room out a window and open another window in the basement when I am spraying. I put weather stripping around the door so it seals when closed. I cut a hole in the wall to provide make up air and covered the openings on both sides with furnace filters. It works for me.

I rinse the cup really well, then put about 4-6 ounces of soapy water in the cup and spray that out. Rinse the cup again, then run 4-6 ounces of just plain water through the gun. Finally, I spray a couple ounces of DNA to remove any residual water. FWIW

-- Art

View GNMG's profile


8 posts in 980 days

#10 posted 05-18-2017 02:34 AM

TungOil, I’ve read quite a bit yo find a readily available waterborne product to spray and found that many people sprayed Polycrylic with grrat success. I’m no expert when it comes to spraying but I have found it to do a good job. Lacquer was my prefered finish for this project but I ended up having to change for safety reasons. The weather isn’t quite consistently warm enough here to spray outside and the bugs you ask? I’m out in the country and surrounded by marshes, my project would just be a landing strip for every bug in the area! Either way, I like to be able to control factors inside rather than risk it outside. I have never finished anything outside for that reason.

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