stunthanger.com

Building Tips and technical articles. => Paint and finishing => Topic started by: Dennis Toth on August 31, 2023, 12:58:47 PM

Title: Paint indoors - window fan
Post by: Dennis Toth on August 31, 2023, 12:58:47 PM
Guys,
I finally couldn't wait any longer for the humidify to drop here is FL so found a solution that allows me to paint (dope) in the shop without the rest of the house smelling like a paint booth. I got a 20" Box Fan at Home Depot~ $25 and sat it on the window sill with the window pulled down to meet it in the shop. It exhausts out through the screen and on setting 2 completely pulls out all the off gas from the dope. While spraying I bumped it up to setting 3 and it pulls out all the over spray and fumes. Below is a picture of it in the window, I used the box to cover the other half of the window to keep it pulling from the inside.

Best,   DennisT
Title: Re: Paint indoors - window fan
Post by: kevin king on September 02, 2023, 12:42:29 PM
Thats an explosion hazard. The spark from an electric motor's brushes or the spark from a light switch or speed adjustment switch on the fan is a problem. I once worked in a paint shop where the guys used an electric drill to stir up a pail of Lacquer and there was no part of the building left standing. Of course people will do it anyway despite what they just read. 
Title: Re: Paint indoors - window fan
Post by: Dave Hull on September 02, 2023, 04:47:00 PM
Hmmm. It depends.

Pretty likely that a somewhat modern box fan would have a shaded pole AC motor. There are no brushes and thus no arcing from the motor. That would be for every user of such a fan in an application like this to verify. Carefully! On the other hand, a lot of electric hand drills, dremels, vacuum cleaners, etc. use an AC universal motor with brushes and are notorious "arc'ers." Many times you can even smell the ozone while they are running!

The issue with the switch arcing is also very real. Chances are that the switch is in a snap-together plastic housing. Not sure I'd trust that to exclude an explosive atmosphere.

I get the risks. A guy I grew up with became a professional painter. He was redoing a bathroom, working on the cabinets and apparently spraying a lacquer material. His boss came in to see how it was going. Unfortunately, he was smoking a cigarette. The bathroom blew up and both were very badly burned. Lots of surgeries and hospital time...and disfigured for life.  Whatever it takes to avoid a situation like that--do it!

Be safe....
Title: Re: Paint indoors - window fan
Post by: kevin king on September 02, 2023, 06:11:12 PM
Windy used and I am sure alot of others have used box fans and shop vacs to clear the room of fumes. Furnace pilot lights are another hazard. Maybe try adding 10 to 15 percent retarder and do a spray test. Randolf makes a universal Retarder in quarts.
Title: Re: Paint indoors - window fan
Post by: RC Storick on September 03, 2023, 01:23:54 PM
Guys,
I finally couldn't wait any longer for the humidify to drop here is FL so found a solution that allows me to paint (dope) in the shop without the rest of the house smelling like a paint booth. I got a 20" Box Fan at Home Depot~ $25 and sat it on the window sill with the window pulled down to meet it in the shop. It exhausts out through the screen and on setting 2 completely pulls out all the off gas from the dope. While spraying I bumped it up to setting 3 and it pulls out all the over spray and fumes. Below is a picture of it in the window, I used the box to cover the other half of the window to keep it pulling from the inside.

Best,   DennisT

That's how I do it.
Title: Re: Paint indoors - window fan
Post by: Steve Dwyer on September 04, 2023, 12:37:06 PM
I hope everyone is wearing a half face paint respirator while working in an enclosed area even with an exhaust fan. I learned the hard way some years back after getting back into building and finishing. I ended up becoming very close friends with a pulmonologist. Former or active smokers, folks with COPD or asthmatics (like myself) are very prone to serious breathing issues from the acetone in our paints.

Steve
Title: Re: Paint indoors - window fan
Post by: Paul Smith on September 05, 2023, 07:34:11 AM
I converted a little-used fireplace into an exhaust system powered by a JenAire stove exhaust.

JenAire quit making parts and forced me to scrap the stove with the exception of the strong exhaust fan.

It works fine for me.
Title: Re: Paint indoors - window fan
Post by: Steve Dwyer on September 09, 2023, 05:49:08 AM
Paul,

Clever configuration. How many CFM is the fan unit and how many air changes per hour are you generating?

Steve
Title: Re: Paint indoors - window fan
Post by: Dennis Toth on September 09, 2023, 08:07:46 AM
With the window Box Fan I have found that I need to keep the room door cracked open so it can pull all the air it wants. I tried it with the door close at first and it was OK but the room slowly got warm and muggy. Going out of the room I noticed it wanted to pull the door open so I lelt it go and it cooled the room and eliminated the humidity as well as the dope smells.

Best,    DennisT
Title: Re: Paint indoors - window fan
Post by: Paul Smith on September 09, 2023, 09:10:43 PM
Paul,

Clever configuration. How many CFM is the fan unit and how many air changes per hour are you generating?

Steve

I don't have the CFM rating for the old Jenn Aire exhaust blower, but it seems like a lot more than cheap box fan. 

I have a bathroom vent blower in my shop, too.  Maybe 100 or 150 CFM.  It doesn't do much besides make noise.
Title: Re: Paint indoors - window fan
Post by: Ken Culbertson on September 10, 2023, 12:00:38 AM
I had one of these mounted in the wall of my old shop.  It really sucked. LL~

https://www.ebay.com/itm/355009839911?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1lg9suXcJTd2pLw-DOOQGzA27&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=355009839911&targetid=4580771614098651&device=c&mktype=&googleloc=&poi=&campaignid=603247547&mkgroupid=1234752552191001&rlsatarget=pla-4580771614098651&abcId=9316119&merchantid=51291&msclkid=173499b3a39315bb8ffcfd4ef9457a46

Ken

Shop was 20' x 10' x 8' = 1600 CF