I have decided to buy an airbrush and compressor, but I am hung up on the issue of a spray booth. I am torn between buying a commercially available spray booth or building my own.
A decent commercially available spray booth starts at about $135 and up. I would like to build one for under $100. The main issue seems to be the exhaust fan. What size should it be? How powerful should it be? Lots of technical data about CFMs, etc.
What do others do for a spray booth? I welcome all suggestions and advice.
Rich
Alton Junction
This is the link to the thread about the Ultimate Hobby Paint Booth that I built.
It cost over $1,000.00 to build, but for my needs, it is perfect.
Prior to that beast, I used a cheap one from Micro-Mark Tools for about twenty years, and it was fine.
-Kevin
Living the dream.
SeeYou190 This is the link to the thread about the Ultimate Hobby Paint Booth that I built. It cost over $1,000.00 to build, but for my needs, it is perfect. Prior to that beast, I used a cheap one from Micro-Mark Tools for about twenty years, and it was fine. -Kevin
richhotrainWhat do others do for a spray booth? I welcome all suggestions and advice.
I made my spray booth using part of an old end table, some left-over sheets of Masonite, and some "L"-shaped aluminum left-overs from installing a drop ceiling in the basement....
...the picture above shows it in my basement workshop, but I later moved it into a very small custom-built room in our 180 year old garage.I added a turntable, cut from some 3/4" plywood, supposedly meant for painting items, but have never needed to use it...I simply hold the item to be painted, either wearing a nitrile glove over one hand, or stick a piece of wood into the body shell of the item being painted.The plastic vent pipe has been replaced with metal furnace pipe, and I used spun fibreglass furnace filters, cut-to-size, and slipped into wooden tracks in the roof of the spray booth.Directly above the filter is a small fan, swiped from an old air-hockey game - it vents the fumes from the sprayed paint directly outdoors, while the excess paint is caught in the filter material.
The spray booth has been in use for almost 40 years.
When airbrushing, I always wear a two-stage respirator, which prevents inhalation of both the sprayed particals and the fumes from the various types of paint.
With the respirator properly worn, you could probably dump a gallon of lacquer thinner and not even smell it. I'd suggest that a two-stage respirator be on your shopping listm, regardless of the types of paint that you use.
Wayne
I need to do the same Rich, I've been putting it off, using the garage when weather permits.
I'll be watching! First time with an airbrush Rich?
That booth Kevin built is awesome, almost like a "commercial" version, I remember his build thread on that.
I'll be doing something more in line with what Wayne built.
Mike.
My You Tube
Hello Rich,
I use an old residential kitchen exhaust hood for my spray booth. I laid it on it's back, mounted it to an old workbench, inverted the motor/fan blades to give me more working room inside the booth, and use cheap 12"x12" filters to capture the overspray before it reaches the motor. I do my spraying in the garage and mainly use acrylics, so odor isn't an issue.
I think the cfm rating would also depend on the length of run for the exhaust. The location (inside the house/in the garage) would be a consideration for the size of cfm. If your spraying lacquers/enamels, the fan should be intrinsically safe as to not create a spark or fire hazard.
If I were to build another spray booth, I would use a squirrel cage fan blower.
Another consideration is lighting. For me, I need LOTS of light while airbrushing, I want the best visiblity to see exactly how it's being applied.
Terry
Inspired by Addiction
See more on my YouTube Channel
Thanks for your reply, Wayne.
What is a two-stage respirator? I have not heard that term before.
I have been planning to buy a 3M Half Mask Respirator, but the term "stage" is nowhere to be found.
Regarding the spray booth, is there a minimum sized exhaust fan that must be used to adequtely vent the fumes?
I took one of those clear plastic storage boxes cut a hole in the bottom. And mounted a squirrel cage fan. I got that off eBay for 50. The box was damaged. Only damage to the unit was a bent flange. A little large at 450cfm. But has a hi low feature. That vents into a hazmat carbon filter. For the rare times I use solvents. Works well. And space for the large scale in there
shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
NVSRR I took one of those clear plastic storage boxes cut a hole in the bottom. And mounted a squirrel cage fan. I got that off eBay for 50. The box was damaged. Only damage to the unit was a bent flange. A little large at 450cfm. But has a hi low feature. That vents into a hazmat carbon filter. For the rare times I use solvents. Works well. And space for the large scale in there shane
Are CFMs the key consideration for a spray booth blower?
Here's a photo of mine, built from plans in the January, 1988 MR. Article was called the Paint Shop Spray Booth by Andy Sperandeo. Had all the information you need.
Rattle cans, a cardboard box, and wait for a nice day works for me. I just don't do enough painting that it would be worth it to invest in an airbrush. Retired, so there's no time pressure. And there are always plenty of other projects.
It takes an iron man to play with a toy iron horse.
Cfm cubic feet per minute. It is the rating measure of the ability of any air moving device. In a spray booth, you want enough air moving to pull 5rough the filter so the booths purpose is fulfilled. The cfm rating of 5e blower thought completely depends on the booth size. Smaller booth, smaller blower. Maybe somebody here remembers the formula for figuring that out based on the volume of the booth. My booth is large because I do large scale at times. Your target will most likely be 150 to 200cfm. Either by a squirrel cage blower or induction motor type. So you don't have the fire risk. Other motors have spark producing elements and have 5e motor mounted in the air stream. Something to keep in mind
The issue of sparks and combustion has come up several times. It is a warning worth heeding. Thanks for the reminder, Shane.
richhotrain The issue of sparks and combustion has come up several times. It is a warning worth heeding. Thanks for the reminder, Shane. Rich
Brand new member here, and basically a brand new model railroader as it's been 35 years since my last and previously only layout.
My other modeling interest is scale plastic race cars. Currently I have 3 Grex air brushes each dedicated to a specific task. I also have a spray booth purchased years ago on ebay which seems to be one of the most popular units sold. I've never until just now heard of any issues with combustion of flamable paint due to sparks from the fan motor. Is this issue geared more towards a home made unit rather then a commercial one?
joel_W
mbinsewi I need to do the same Rich, I've been putting it off, using the garage when weather permits. I'll be watching! First time with an airbrush Rich? That booth Kevin built is awesome, almost like a "commercial" version, I remember his build thread on that. I'll be doing something more in line with what Wayne built. Mike.
Joel_W richhotrain The issue of sparks and combustion has come up several times. It is a warning worth heeding. Thanks for the reminder, Shane. Rich Brand new member here, and basically a brand new model railroader as it's been 35 years since my last and previously only layout. My other modeling interest is scale plastic race cars. Currently I have 3 Grex air brushes each dedicated to a specific task. I also have a spray booth purchased years ago on ebay which seems to be one of the most popular units sold. I've never until just now heard of any issues with combustion of flamable paint due to sparks from the fan motor. Is this issue geared more towards a home made unit rather then a commercial one? joel_W
I would want a paint booth with an external blower motor. If you are using flamable vapor paint, cleaner or paint remover or non-flamable vapor paint you would not want the paint mist and vapors passing over/through the motor. Motor brushes ware and make sparks, sparks and flamable vapor make for an exciting time at the least.
It is also easier to clean the paint residue off the squirrel cage only then the squirrel cage and the motor.
I can say that I don't recall hearing of anybody that blew off their exhaust pipe.
My home made all sheet metal spray booth with an external blower motor may very well be over 30 years old. A lot of air and flamable Floquil and other brands of paint went through that blower wheel.
Heck, one time even a chipmunk came down the exaust vent, past the blower wheel and chewed it's way through the filter.
Hi Rich,
I built my own spray booth mostly out of stuff I had laying around the garage.
I used:
- a 16" square 3 speed box fan,
- 16" x 16" fibre furnace filters,
- scrap 1/2" plywood,
- a small LED light bar,
- a power bar (optional),
- a pressure regulator with gauge (optional),
- various hose fittings,
The shape of the booth looks fancy but it was dictated more by the size of the plywood scraps than function.
The pressure regulator and gauge are there for convenience. They are not necessary. They just save me from having to walk to the compressor to make fine adjustments.
The power bar allows the fan and the light to be shut off all at once. You could also plug a small compressor into it.
The filters clog up very quickly so they have to changed on a regular basis. To test how clooged the filters are, turn the fan on and then pull the filter away from the fan. If the fan speed increases noticeably then the filter needs to be replaced regardless of whether it looks clogged or not.
Suitable fans can be purchased on eBay for peanuts. Here is one example. This one is 16" x 16". It doesn't mention whether or not it is a brushless motor (i.e. no sparks) but IMHO you would have to be putting a lot of overspray into the air before there is a risk of explosion. That is highly unlikely when painting models (let the debate begin!!) Just make sure that the area is well ventilated:
https://i.imgur.com/ZQbaFWx.jpg
As you are probably aware, you can buy either dedicated air brush tankless compressors, or slightly larger multi-purpose compressors. Here is one example of a dedicated air brush compressor:
https://www.amazon.ca/Timbertech-Professional-Upgraded-Airbrush-Compressor/dp/B07VT2F5N9/ref=sr_1_5?crid=38880MHHP24SW&keywords=airbrush+air+compressor&qid=1668129761&qu=eyJxc2MiOiIzLjg3IiwicXNhIjoiMy4wOCIsInFzcCI6IjIuNDUifQ%3D%3D&sprefix=air+brush+compressors+%2Caps%2C115&sr=8-5
I suggest considering the larger option just because it may come in handy for a whole bunch of other uses. Note that there are huge differences in the noise levels between the various designs. My old 'pancake' compressor was deafening! My new unit makes very little noise. It is similar to this:
https://www.amazon.ca/California-Air-Tools-CAT-1P1060S-Compressor/dp/B01LYHYHEA/ref=sr_1_20?crid=QTIJS7XMPA2&keywords=air+compressors+portable&qid=1668129584&qu=eyJxc2MiOiIyLjY0IiwicXNhIjoiMi4wMCIsInFzcCI6IjEuMDAifQ%3D%3D&sprefix=air+compressors%2Caps%2C115&sr=8-20
Keep in mind that the prices are in Canadian dollars.
Cheers!!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
I spray paint out of doors, on my deck. I just lay some newspaper down to keep the paint off the deck. Keeps the paint smell out of the house.
David Starr www.newsnorthwoods.blogspot.com
richhotrainWhat is a two-stage respirator? I have not heard that term before.
I first learned of them when I started my job in a steel mill. The respirator is equipped with elasticised straps to hold the face-portion tight against the face, so there's no chance of fumes getting past the mask.
The term two-stage refers to the fact that the filter cannisters, which screw onto the mask, will prevent both particulate matter, and fumes from the paint, from entering your lungs.
Here's a picture, luckily without the mask on my face...didn't want to scare anybody....
When I'm airbrushing, there's no smell of paint or thinners and no paint-dust residue on the hairs in my nose, either.
In a steel mill, the filter cannisters often needed to be changed daily, and sometimes several times a day. When using a ventilated spray booth, the filter cannisters can last for months or even years.
The mask and cannisters should be available at any outlet offering safety gear.
It's always puzzled me why many spray booths have the filter screens and vent ducts at the back of the spray booth, directly in the path of the sprayed paint. Seems to me that you'd have to be changing the filters every time you painted an item.I've painted over 40 freight cars in a session and in some cases, did similar work daily for a couple of weeks, before the top-mounted filter needed to be changed. Sure, there's lots of overspray on the back of the booth, but it's stuck there for good, and not hurting anything.
PC101 I would want a paint booth with an external blower motor. If you are using flamable vapor paint, cleaner or paint remover or non-flamable vapor paint you would not want the paint mist and vapors passing over/through the motor. Motor brushes ware and make sparks, sparks and flamable vapor make for an exciting time at the least. It is also easier to clean the paint residue off the squirrel cage only then the squirrel cage and the motor. I can say that I don't recall hearing of anybody that blew off their exhaust pipe. My home made all sheet metal spray booth with an external blower motor may very well be over 30 years old. A lot of air and flamable Floquil and other brands of paint went through that blower wheel. Heck, one time even a chipmunk came down the exaust vent, past the blower wheel and chewed it's way through the filter.
I don't want to leave anyone out here. I appreciate each and every post. So, thank you, Terry, maxman, Mister Beasley, Joel_W, Dave and David.
doctorwayne richhotrain What is a two-stage respirator? I have not heard that term before. I first learned of them when I started my job in a steel mill. The respirator is equipped with elasticised straps to hold the face-portion tight against the face, so there's no chance of fumes getting past the mask. The term two-stage refers to the fact that the filter cannisters, which screw onto the mask, will prevent both particulate matter, and fumes from the paint, from entering your lungs. Here's a picture, luckily without the mask on my face...didn't want to scare anybody.... When I'm airbrushing, there's no smell of paint or thinners and no paint-dust residue on the hairs in my nose, either. In a steel mill, the filter cannisters often needed to be changed daily, and sometimes several times a day. When using a ventilated spray booth, the filter cannisters can last for months or even years. The mask and cannisters should be available at any outlet offering safety gear. It's always puzzled me why many spray booths have the filter screens and vent ducts at the back of the spray booth, directly in the path of the sprayed paint. Seems to me that you'd have to be changing the filters every time you painted an item.I've painted over 40 freight cars in a session and in some cases, did similar work daily for a couple of weeks, before the top-mounted filter needed to be changed. Sure, there's lots of overspray on the back of the booth, but it's stuck there for good, and not hurting anything. Wayne
richhotrain What is a two-stage respirator? I have not heard that term before.
Your comment about the position of the filter screen intrigues me. I have no answer for why most filter screens and vent ducts are mounted at the back of the spray booth. Placing these two parts at the top of the spray booth does make sense to me. Perhaps a more knowledgeable reader of this thread can provide an answer.
Good morning Rich
As cost effective as they are, I thought I'd point out that I've used those inline duct fans through the years in construction for different reasons. That's what I plan to use when I make a spray booth as well.
I remember when they were 15 - $20.00 bucks. Now-a-days they're 40 - $60.00 for the higher CFM ones but still a reasonable price for your objective.
I had one running constantly through the wall to an exterior wall closet that used to get mold on the walls. I'd flip the switch every late fall and that thing ran all winter. Later I got smart and put a thermostat switch in the closet. That thing ran over 15 years and was still working when I sold the house.
TF
Thanks for that post, TF. I really do like the idea of the inline duct fan because it also provides an attachment to vent the fumes outside of the work space. For those fans with brushless motors, the spark issue is eliminated. So, that seems to me to be the exhaust fan of choice.
NVSRR Cfm cubic feet per minute. It is the rating measure of the ability of any air moving device. In a spray booth, you want enough air moving to pull 5rough the filter so the booths purpose is fulfilled. The cfm rating of 5e blower thought completely depends on the booth size. Smaller booth, smaller blower. Maybe somebody here remembers the formula for figuring that out based on the volume of the booth. My booth is large because I do large scale at times. Your target will most likely be 150 to 200cfm.
Cfm cubic feet per minute. It is the rating measure of the ability of any air moving device. In a spray booth, you want enough air moving to pull 5rough the filter so the booths purpose is fulfilled. The cfm rating of 5e blower thought completely depends on the booth size. Smaller booth, smaller blower. Maybe somebody here remembers the formula for figuring that out based on the volume of the booth. My booth is large because I do large scale at times. Your target will most likely be 150 to 200cfm.
https://cs.trains.com/mrr/f/88/p/282494/3246026.aspx#3246026
Here is what the poster had to say about determing the appropriate CFMs:
For fume hoods at research labs the face velocity is typically maintained at 100 feet per minute. Based on that:
CFM = face velocity x area
if your hood opening is 24 x 18 (2' x 1.5') then
CFM = 100 x 2 x 1.5 = 300 CFM
use the above formula and adjust for your face area. A thin filter probably has a pressure drop around .25" when somewhat dirty with paint. The duct pressure drop if short and say 1 elbow maybe adds another .25". So if you can find fan data that includes the CFM and pressure, using the above example, pick a fan that moves 300 CFM while developing at least 0.5" pressure. If, say your CFM works out to be 400 CFM, find a fan that produces 400 CFM again at 0.5" pressure.
A few examples from my "minimalist" school of car painting.
This is from an unpainted Bowser PCC car. The paint is done with rattle cans from the hardware store and blue painters' masking tape. I printed the decals myself on my inkjet printer. The model came with no window glazing. It looks like I made at least a windshield with a piece of acetate.
Here's another trolley. This one is a Bachmann Peter Witt model, which I got undecorated and unpainted. It came with flush with the surface plastic window glazing. Again, rattle can paint and tape for masking.
Finally, a pair of very old Tyco streamline passenger cars. These were all aluminum bodies and only had a sheet of fogged acetate stuck inside as window glazing. Flush-mounted plastic windows would have improved the model. I got some of thes in an old box of trains, and some from ebay decades later, so I guess all the detailing was oringinal. The box of trains ones had some applied decals, that were literally peeling off, so I just removed them.
The car on the right has been done, the car on the left has not. I'm not sure if I painted them or just thoroughly cleaned them and applied a gloss coat of spray paint. Again, masking was done and the stripe applied with rattle can paint. I used store-bought decals for numbering and created a decal on my printer for each car's name tag. The car on the right is a dining car. It is named after Alferd (yes, that's how he spelled it) G. Packer, the only person in the United States ever convicted of cannibalism.
richhotrainFor fume hoods at research labs the face velocity is typically maintained at 100 feet per minute. Based on that: CFM = face velocity x area if your hood opening is 24 x 18 (2' x 1.5') then CFM = 100 x 2 x 1.5 = 300 CFM
I've been following along a bit here from the balcony. From your most recent post what I believe I'm observing, if I may politely say, is a bit of analysis paralysis. I think you might be trying to tackle this beast from all sides before you even have the airbrush in your hands.
Don't confuse fume hoods with spray booths. Two different animals. I worked on dozens of fume hoods at GE and the specs mentioned above are very important for OSHA standards and employee safety.
Many of our hoods were used to vent very poisonous gases. It was imperitave that they worked. I could go on about the ins and outs of designing and maintaining these things. The air velocity of a fume hood is considerably greater than what a paint booth would require.
My advice to you is to take a step back and maybe get the airbrush (or two) of your choice and a source of compressed air. If you want to "play" with a booth use some of the suggestions from above and set up a simple box or perhaps a larger storage container, mount a larger "pancake" fan in the top or side or back and place some furnace filter material over it to keep the paint solids from gumming up the works.
Set up your temporary "pilot operation" in a well ventilated area, maybe a porch or garage, or at least you can get some flexible dryer vent duct and direct it temporarily out a window. Then get familiar with your actual airbrush painting technique.
Once you have a feel for that and have an idea of what paints you'll be shooting you can get a better grasp on what kind of "atmosphere control" you would like.
In my setup I simply have an overhead exhaust fan to pull the VOCs out of the air and pull in some "make-up" air from other parts of the train room. I placed a register on the basement door so that when my exhaust fan is running some make up air can be drawn into the room. For every cubic foot of "bad air" you're trying to get rid of you have to have a cubic foot of good air come in from... somewhere.
Many of my painting projects are large structures and the average hobby paint "booth" wouldn't give me the necessary "elbow room" to navigate in. Some modelers, however, don't have the need for anything too large since they primarily focus on locomotive and rolling stock painting and/or weathering.
Hope that helps, Ed
gmpullman Hello Rich, I've been following along a bit here from the balcony. From your most recent post what I believe I'm observing, if I may politely say, is a bit of analysis paralysis. I think you might be trying to tackle this beast from all sides before you even have the airbrush in your hands.
gmpullmanat least you can get some flexible dryer vent duct
Get the flexible metal stuff, not the plastic. The plastic eventually rots and falls apart.
maxmanGet the flexible metal stuff, not the plastic.
I was going to suggest going with 6" or even 8". The corrugations actually slow down air movement. I don't know how far Rich would have to go with his "permanent" paint booth to vent outside.
6" 4 layer aluminum flex duct:
https://a.co/d/dNPCHYx
I was fortunate that I had a 16" x 36" void behind an upstairs shower stall that I could run strait sections of galvanized duct work straight up through to the attic and vented to the eaves. I have a dual-cage industrial blower connected to this with a variable speed control.
Regards, Ed