Is a basement spray booth a dangerous idea?

[rodger.]

Because of the cold weather here, I still cannot spray finish in my garage or driveway. I have had a project on hold for a while, and decided to brush on the finish today instead of waiting any longer.

I think I am good at brushing on finish, but I really prefer to spray and I have the equipment to do so. My issue in a location.

I want to build or set up some type of spray area in basement. I have the space, and am willing to frame out a dedicated room if that's what it takes. Has anyone done this before? What did you use for ventilation or overspray removal? The only windows are the typical basement windows, and measure about 36 wide and 24 high.

I have posted a similar question a while ago, but would like to "kick the idea around" again, as Eric says!

I spray water based only, and use hvlp. I was thinking perhaps of using an old furnace blower in some way to help remove the overspray.

Here is the general area where I finish, and could convert to a spray area/booth.

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[wtnhighlander]

An aquaintance of mine is an auto body guy. His spray booth has a reasonably sized blower ( like a large furnace unit) pulling air through an entire wall of pleated filters. You shouldn't need that much, but I would plan several square feet of filtration. And maybe the entry door should be placed across from the filters, and louvered to allow the fresh air in. And even with water bourne finishes NEVER neglect to wear your respirator!

[rodger.]

An aquaintance of mine is an auto body guy. His spray booth has a reasonably sized blower ( like a large furnace unit) pulling air through an entire wall of pleated filters. You shouldn't need that much, but I would plan several square feet of filtration. And maybe the entry door should be placed across from the filters, and louvered to allow the fresh air in. And even with water bourne finishes NEVER neglect to wear your respirator!

I always wear a respirator when finishing, even when I'm not spraying. I really hate the fumes of any finish, and my respirator is reasonably comfortable, so I just wear it whenever I finish.

I agree with your idea about having a large open space across from the filters. Wouldn't be too hard to frame in a double door opening there.

[rodger.]

Here is an article I found by reputable woodworker.

http://news.thefinishingstore.com/?p=1277

[STL Woodguy]

For the same reasons of the extreme cold, I set up a makeshift spray room out of an unused bathroom in my basement. Plastic is hung all around Dexter-style to keep finish off the walls, I have a small box fan nearby with a filter attached to collect - as best it can - any airborn spray nearby. It's not ideal as I can't vent outside from that room, but it does work pretty well for what it is, all things considered. Respirator is a must, and clearly water based finish only. The advantage of being a small room is that it's segregated from the dust in the shop outside, I just keep the door closed and the plastic is a second barrier. 

 

But now that it's warming up again, I'll probably head back outside, especially as I am more of a fan of oil based finishes.

[Marco Divetta]

Do you have any heating system for your home in there or air exchange vents ???

I think any room with sufficient ventilation to clear the air is suitable for spraying.

I spray in a bay window and I have two pieces of MDF cut to the size of my window openings with small fans set into them that blow the air out through filters.

As long as it's not raining heavy they take care of a lot of the overspray .

I'd set up the spray are a bit closer to that window with some sort of over head extraction and two small sections of studding floor to ceiling left and right of the window just to channel the airflow up and to contain the overspray a bit, and if possible I'd move the pice to another part of the room to dry.

[rodger.]

Do you have any heating system for your home in there or air exchange vents ???

I think any room with sufficient ventilation to clear the air is suitable for spraying.

I spray in a bay window and I have two pieces of MDF cut to the size of my window openings with small fans set into them that blow the air out through filters.

As long as it's not raining heavy they take care of a lot of the overspray .

I'd set up the spray are a bit closer to that window with some sort of over head extraction and two small sections of studding floor to ceiling left and right of the window just to channel the airflow up and to contain the overspray a bit, and if possible I'd move the pice to another part of the room to dry.

I like the idea of overhead extraction. You mean kind of like a large vent hood?

I do have a heating supply line right above the window, but that is easy enough to cover up or remove. There are no return air lines, as the basement is unfinished. Both the furnace and hot water unit are miles away in another part to the basement.

[Marco Divetta]

Yeah exactly .... If you can just get a small draft going that will pick up the particles in the air it will help a lot. A lot of professional spray booths have a fan blowing air from one end and another extracting at the other creating a very slow but controlled air flow.

As for the furnace be very careful even if it's far away, they work by drawing in air to mix with the fuel and if the air is dirty ( over spray ) it could cause problems, just check the vents and if you see a buildup of anything you might have to section off you spraying area.

[AceHoleInOne]

 

 

I built a down draft table using an old direct drive furnace motor and 20x20 high micron furnace filters. I only spray water-based in my basement. Hang bed sheets and plastic for walls. I direct the "filtered" airflow out a door into another portion of my basement. 

 

Large projects get sprayed in the garage. I use a propane torpedo heater to warm the garage. Shut it off and spray, bring piece in house to dry. 

 

-Ace-

[dwacker]

Box fans will not move enough air through a furnace filter. This is plain and simple, you need to move much more air than any makeshift box fan will ever move through a filter. Your better off skipping the filter and using a box fan to move the air out a window and sacrifice the heat.

[AceHoleInOne]

One of my goal's, I do have another furnace fan, is to build a "filter wall" and use a large flex pipe attached to the back and exhaust out a basement window. Someday that will happen, just never got around to it. 

 

-Ace-

[ChrisM]

I've gone the box fan sitting in the window route, without a filter, and as mentioned it won't even keep up, the basement gets pretty foggy. Now granted, I sometimes get a decent wind blowing IN to the window, and I can actually hear the fan slow down. I was also spraying with a HVLP where I suspect I had the pressure set too high. I had a fan behind me, and two large plastic curtains for walls. I quit using the rear fan because I felt the window fan couldn't exhaust fast enough and the rear fan was just spreading the cloud more.

 

For my next project, I think I'm going to make a more enclosed booth out of sheet foam, with two walls and a roof, see how that works. Plus, I have a new Fuji turbine to try out!

[Marco Divetta]

A fan inside your spray would create to much turbulence, even on its lowest setting.

If your going small scale and not spending to much money all you need to do is get a small draft going whilst your spraying and a minute or two after, just enough to get rid of that cloud a bit faster.

You also need to be close to the window so the particles can be picked up by the concentrated air flow, it won't work if your in the middle of a twenty foot square room.

[dwacker]

A fan inside your spray would create to much turbulence, even on its lowest setting.

If your going small scale and not spending to much money all you need to do is get a small draft going whilst your spraying and a minute or two after, just enough to get rid of that cloud a bit faster.

You also need to be close to the window so the particles can be picked up by the concentrated air flow, it won't work if your in the middle of a twenty foot square room.

 

Air going in and being push out is more like a down draft booth. Just take a little more thought. I have 12 box fans pushing straight down works very well.

[Marco Divetta]

Air going in and being push out is more like a down draft booth. Just take a little more thought. I have 12 box fans pushing straight down works very well.

I agree but you still have to give all that air some place to go and it has to be extracted in equal quantities it can't just bounce of a small vent in the floor and back up again there has to be a flow, I'm sure even your finish area has some place for all that air to go, and yes 12 fans would clear the air very fast but not everybody is up to that level of production YET

[dwacker]

I agree but you still have to give all that air some place to go and it has to be extracted in equal quantities it can't just bounce of a small vent in the floor and back up again there has to be a flow, I'm sure even your finish area has some place for all that air to go, and yes 12 fans would clear the air very fast but not everybody is up to that level of production YET

 

I just use cheap box fans but your right the air does have to have a place to go. A down draft booth usually has a small exhaust. We just looked at a new one with a 24x24 exhaust but the fan was a monster.

[Marco Divetta]

I just use cheap box fans but your right the air does have to have a place to go. A down draft booth usually has a small exhaust. We just looked at a new one with a 24x24 exhaust but the fan was a monster.

Just out of curiosity and slightly off topic .... I'm guessing the price isn't something you'll offset in six months.

Here a side downdraft 12' x 8' booth ( motorcycle booth ) without air lines costs in the are of €8000

[dwacker]

Just out of curiosity and slightly off topic .... I'm guessing the price isn't something you'll offset in six months.

Here a side downdraft 12' x 8' booth ( motorcycle booth ) without air lines costs in the are of €8000

 

Its the law so its irrelevant I can get away with more at my house but with a new commercial building there is no getting around it. Just cost of business. 

[rodger.]

Well I found a furnace fan and squirrel cage, so I need to find a time to go and get it from the HVAC guy.

I was thinking about framing out a small room, maybe 10 feet wide and 10 feet deep, and sheeting the walls with vapour barrier, or maybe 1/8 inch hardboard. Then I could have an enclosed area. The wall behind me would be open, and the furnace fan will exhaust the air out the window.

Now if I could just come up with a plan for how to place the fan, or a chase, or something to direct all that air to where it needs to go.

[AceHoleInOne]

Well I found a furnace fan and squirrel cage, so I need to find a time to go and get it from the HVAC guy.

I was thinking about framing out a small room, maybe 10 feet wide and 10 feet deep, and sheeting the walls with vapour barrier, or maybe 1/8 inch hardboard. Then I could have an enclosed area. The wall behind me would be open, and the furnace fan will exhaust the air out the window.

Now if I could just come up with a plan for how to place the fan, or a chase, or something to direct all that air to where it needs to go.

 

 

http://www.harborfreight.com/8-inch-ventilation-duct-97763.html#.UykLzq1dXKk

 

Well...I was rolling this idea around for mine.  Not sure about static? But this product is used for ventilation.

 

-Ace- 

[dwacker]

Well I found a furnace fan and squirrel cage, so I need to find a time to go and get it from the HVAC guy.

I was thinking about framing out a small room, maybe 10 feet wide and 10 feet deep, and sheeting the walls with vapour barrier, or maybe 1/8 inch hardboard. Then I could have an enclosed area. The wall behind me would be open, and the furnace fan will exhaust the air out the window.

Now if I could just come up with a plan for how to place the fan, or a chase, or something to direct all that air to where it needs to go.

 

You will need a 10,000 cfm fan to keep your 10x10 clear. Furnace fans dont move anywhere near close to that.

 

Something like this will get you 2/3 of what you actually need for an affordable price.

 

http://www.industrialfansdirect.com/IND-FA-EF-GP/JD-VES24.html

[AceHoleInOne]

You will need a 10,000 cfm fan to keep your 10x10 clear. Furnace fans dont move anywhere near close to that.

 

Something like this will get you 2/3 of what you actually need for an affordable price.

 

http://www.industrialfansdirect.com/IND-FA-EF-GP/JD-VES24.html

 

 

 

 

If your spray area size is 10x10x8 = 800CF Say the average furnace fan run on high speed is 1200CFM. Say the filters and ducting slow the airflow to 1000CFM. One can assume the air in the room will be changed-out in less than one minute. So wouldn't  that be sufficient?

 

10,000 or even 6450 CFM would be way overkill, clothes would be torn off your body  . Am I missing something?

 

-Ace-

[dwacker]

If your spray area size is 10x10x8 = 800CF Say the average furnace fan run on high speed is 1200CFM. Say the filters and ducting slow the airflow to 1000CFM. One can assume the air in the room will be changed-out in less than one minute. So wouldn't  that be sufficient?

 

10,000 or even 6450 CFM would be way overkill, clothes would be torn off your body  . Am I missing something?

 

-Ace-

 

NO that is not correct unless you have a fan than magically selects only the contaminated air.  A booth of any type should move 100+ cfm per sq ft of the front open wall. So no its not overkill in the slightest in fact it the laws low limits for any commercial spray booth. 6450 is well below the "legal" limits and since this is not a commercial shop should be some why reasonable to balance economy and safety. A furnace fan is no where near close.

[AceHoleInOne]

NO that is not correct unless you have a fan than magically selects only the contaminated air.  A booth of any type should move 100+ cfm per sq ft of the front open wall. So no its not overkill in the slightest in fact it the laws low limits for any commercial spray booth. 6450 is well below the "legal" limits and since this is not a commercial shop should be some where reasonable to balance economy and safety. A furnace fan is no where near close.

 

In my opinion. That 6450 CFM is way too much air flow for such a small space. So much so, more than likely the air being pulled through will actually impede the ability of the spray pattern coming off the spray gun, in addition, a finish drying to fast wont flow out.  You don't want a strong wind when spraying. Just clear the space in a reasonable amount of time. 

 

-Ace-

[dwacker]

In my opinion. That 6450 CFM is way too much air flow for such a small space. So much so, more than likely the air being pulled through will actually impede the ability of the spray pattern coming off the spray gun, in addition, a finish drying to fast wont flow out.  You don't want a strong wind when spraying. Just clear the space in a reasonable amount of time. 

 

-Ace-

 

Have you ever used a spray booth?? Exhaust fans dont create a breeze that is not how a spray booth works. No it wont affect the finish nor will it pull the finish away from the work surface.

 

Here is one that is actually smaller than the proposed 10x10 in fact half the depth.

http://thefinishpro.com/store/product.php?productid=16172&cat=263&page=1

 

Here is the one Im ordering that is running 12000 cfm and is closer to the proposed 10x10

http://thefinishpro.com/store/product.php?productid=16224&cat=263&page=1

 

Both just barely meet legal limits most shops run much higher cfm rating. to create any sort of breeze in a 10x10 booth with an exhaust fan you would have to push it up over 24000 cfm.