DIY Paint Booth did you make one lets see it.

shipclambake

Double Actioner
I'm thinking about making a DIY paintbooth from a large plastic tote with filter and an in-line exhaust. If you've made a DIY paintbooth please post it Id like some ideas for my booth.
 
I made my own out of a large-ish storage box with a bathroom extractor fan in the corner vented through a 4" flexible hose.
total cost about £30.
there's enough room but the extraction at 85 cubic metres an hour is insufficient.

I'm tempted to get one of the fans below that pulls 185 cubic metres which is the same as some of the two fan portable ones.

https://www.ebay.co.uk/itm/High-Pow...2b&brand=VENTS&_trksid=p2047675.c101195.m1851
 
Just dropping this in here again:
http://www.modelersite.com/Abr2003/english/Spray-booth-design_Eng.htm

Not mine, but I like to share it around because it actually gives the basic formulas for figuring out what fan specs you need for your booth size and duct situation. The interwebz is full of bad DIY spray booth builds because literally anyone can slap some cheap fans on a box and take pics. Don't assume it works just because it makes a noise and you can feel airflow: figure out the fan specs you actually need, and make sure.
 
Just dropping this in here again:
http://www.modelersite.com/Abr2003/english/Spray-booth-design_Eng.htm

Not mine, but I like to share it around because it actually gives the basic formulas for figuring out what fan specs you need for your booth size and duct situation. The interwebz is full of bad DIY spray booth builds because literally anyone can slap some cheap fans on a box and take pics. Don't assume it works just because it makes a noise and you can feel airflow: figure out the fan specs you actually need, and make sure.
you done this? be interesting to see your booth and calculations.
 
you done this? be interesting to see your booth and calculations.

Sort of, but not entirely. I made plans to: figured out what size booth I wanted and how much ducting it would need for where it would be, did the math and bought a blower that matched the specs... then my living situation changed, and I had to shelve the project. I still want/need to do it, but I need to figure out how to reshuffle my living space for it, so right now my "spray booth" is the great outdoors and a respirator.

Originally the booth I was going to make would have been a 2x2 foot face cross-draft design, with ~6 feet of 6 inch duct w/ 2 right angle bends. That's (2' x 2') x 100 = 400CFM for the booth itself. For the ducting, that's (12" x 2) + 6' = 8'. The static pressure table on the website doesn't have figures for 6" @ 400CFM, but loose extrapolation of the figures it does give implies I can round it up to .5", (that will also give me a certain built-in safety margin). Calculated for length, that's (8' x .1) x .5 = .4 . Multiply by 3 since I'd be using flexible duct, and I need a fan capable of delivering 400CFM at 1.2"SP.

My apologies for all the Imperial measurements. I prefer metric for most things, but Imperial is what the formulas on the website use.

The blower I ended up getting was this one:
https://www.amazon.com/gp/product/B000BK859C/
https://images-na.ssl-images-amazon.com/images/I/91KOewHssvL.pdf
Shaded pole (not rated explosion proof, but shaded pole is still much, much better than having the motor fully exposed in the air stream), and 510 CFM@ .2"SP. Comfortably over my needed specs, but that's good, as it gives me some flexibility in case I have to increase the duct length or otherwise change something.

The "gotcha" is that finding something cheap that moves enough CFM is easy, but without good enough static pressure rating, that CFM means nothing, and finding fans/blowers with higher static pressure is difficult. For starters, most common fans don't even list static pressure rating at all. Finding something with good enough CFM, AND good enough static pressure, AND a shaded/external motor drives the cost up. But without that you don't actually have a functional and safe spray booth, you just have a spray booth-shaped noisemaker.

For example: if using computer fans, I'd need at least 4 of these to meet the numerical specs, but it would not be fire-safe. Note that's not even a case fan: it's a radiator block fan. Case fans can't do the job at all. HVAC fans like bathroom fans can meet the specs more cost-efficiently (pushing air through ducts is what they're designed for), but again: not spark/fire safe.

And even with bathroom fans, you'd have to check the specs properly. This is actually my second spray booth project. My first was a plastic tub with a bathroom fan, much like in many of the tutorials you see online. I only looked at CFM and price when I was buying the fan. It moved air, but not nearly enough. That's what sent me looking for better tutorials with actual engineering in them.

The original plan was to make this booth from aluminum extrusion w/ clear acrylic panels, but when I actually priced out the materials it was WAY too expensive. The dirt-cheap alternative would be laminated cardboard. I lack to tools to do it in wood, otherwise that would be the best balance of economy and quality. 6-inch duct is surprisingly hard to get at all, much less economically, but dropping to the common 4-inch raises the static pressure to the point where I wouldn't be getting enough CFM anymore.

This does illustrate why so many people are inclined to throw critical thinking out the window , and just blindly throw something together with computer or bathroom fans. Tell people that doing it right requires math homework, then offer an "alternative" that costs pennies in comparison, and most of them'll start handwaving like they're in a 40's musical.
 
very interesting. I don't know what science says about the minimum amount of extraction is required, if indeed it is measurable, I guess the answer would be 100% of particles.
It sort of puts into question the validity of virtually all of the portable airbrush booths marketed.
I only have a small work area, say 3feet by 2.5feet so I naturally went for the plastic bin and extraction fan in the corner, and having compared it against some of the mass market booths it seemed a good option.
now however I have to look again, and I've found this fan https://vevor.co.uk/products/axial-...tchen-exhaust-fa?_pos=19&_sid=dd6edc835&_ss=r
which I think cuts the mustard and is manageable in size. I can get an 8" to 4" reducer foir £11, mount it on the back of a suitable box and have the hose 3 feet long and going straight out of a window.
let me know what you think of the fan.
 
20200225_151356 (1).jpg20200225_151407 (1).jpg20200222_171634 (1).jpg
I built this thing many yeas ago. It was a plastic booth I got at a hobby shop who sold HO trains and kits and all sorts of items. It was a plastic booth and the motor had a pulley and the fan was a small aluminum 4 blade belt driven thing. It never worked . I built this and it started out much larger so I redid it . I used the same fan motor , went to a hardware store so long ago and bought a squirrel cage fan that came with a matching housing. I had a square outlet so I used a 4" coffee can soldered to a brass sheet metal plate with a 4" hole cut in it. Used gasket material for a seal as you can see in the photos. I had to reverse the motor rotating , on this type of brushless motor all I did was remove the field and reverse it , problem solved . I do have a filter just not shown here. A regular paper furnace filter. I would need to measure the size of the booth . I based the last re do on plans I found online to have better air pull. With 2 lite candles at the front fan on the flames pull to the back , it has a very good air pull. I can't recall where I found the plans, I'll look , I know I have a copy on this PC.

William
 
Here is the link to the plans I used to alter my booth .

I did it with the one I built which does not have the back angle for the fan . What I did instead of trying to tear mine apart since it's glued together is I made the angle inside , just added plywood I had to the top so there is an open chamber between the angled top and the fan intake . Difficult to explain . It does work . If you look at this site you can see what others have done.
 
The first link will show a couple of pics from this forum. From vid I put up on YouTube a few years ago of my booth design


The below link is to my second part of my YouTube video.
The part 1 is about the theroy behind my design it.

 
The basics are. You need to think of the booth as high and low pressure areas while moving large volumes of air, all the time keeping the air flow laminar.
To achieve this
The easiest way is the largest square ducts as possible.
Keep the fan as far from the filter media as possible. The rotating fan will spiral air flow in a duct for quite a distance and reduce air volume due to increased air speed
The faster the air speed. The more friction, the more noise, and it is an exponential problem. And there is a point, no amount of horsepower will make air move faster so big and slow is the way to go.
The filter needs to be as large as the opening of your booth bigger even. For quite a few reasons,
One the slower the air moves through the filter the friction losses are reduced
There are no dead zones for particulates to become trapped in corners air will go around corners but the particulates will want to travel in a straight line because of there mass.
 
I need to make an evac system. Unfortunately my airbrushing area is in the living room. Hoping to get an outbuilding to setup in soon. Both my hobbies are slowly taking over the living room. Thankfully I have a supportive spouse.
 
I need to make an evac system. Unfortunately my airbrushing area is in the living room. Hoping to get an outbuilding to setup in soon. Both my hobbies are slowly taking over the living room. Thankfully I have a supportive spouse.
When painting in the home you can put a large box fan in the middle of the opening of one window, blowing from the outside into the room you can close the window on it to hold it in position with a rolled up towel on it (stops the glass rattling too). You don't need to seal around it, it will act like a bit like a venturi and pressurizing the room.
Then setup your booth box, plastic tub ect. in another window made from core flute, card board ect.(used house for sale or political signs and gaff tape) Now you only to need to, reasonablly seal around the booth.
( Make the booth the same surface area or larger of the fan. The width of the window is a good idea but not to big) Then at the back of your booth you can use one or 3 layers of wadding as a filter (wadding is avaliable from frabic shops) now close all doors into that room and put draft snakes under the doors or rolled up towels, close any A/C vent in the roof or floor.
Now you need to check around the window your painting in. Is not above a car, down stairs window A/C, neibours window "you get it" "you will spill paint inside your booth".
Wadding, filters about 25 to 40% per layer of wet paint particals, 80%+ of dry particals will go straight through along with solvent vapors so having it above or near the kids room, playground other windows that are not closed is a bad idea. So for $20 plus dollars you are on your on your way.. i have more tips on it but this is to long aleady.
 
Well the up side, is that most of the paints are waterbased and the filter seems to be a nice particulates filter. The variable fan speed is nice to keep the noise wering a foot and half from your head and draw where you want it.
Being a positive pressure vent duct, leaks will be easily noticable.
The booths vent above the Aircon will more than likely create a happy painting environment for a while 😁💀 when using solvents i see up the back.
I would hope its on recycle while painting at the same time the A/C is on
The radiator fins at the rear of the A/C are in for a treat too with some insulating and a moisture holding coating coming it's way.

Please tell me it's set up for the mother in law.🤭

If the duct go's through the window to another 3 + meters of piping then all shoud be good mostly its a little hard to tell what kind of air pump being used
 
Well the up side, is that most of the paints are waterbased and the filter seems to be a nice particulates filter. The variable fan speed is nice to keep the noise wering a foot and half from your head and draw where you want it.

Actually most of the paints are alcohol and lacquer based.

I would hope its on recycle while painting at the same time the A/C is on

Why.

The radiator fins at the rear of the A/C are in for a treat too with some insulating and a moisture holding coating coming it's way.

Please tell me it's set up for the mother in law.🤭

No idea what this means.

If the duct go's through the window to another 3 + meters of piping then all shoud be good mostly its a little hard to tell what kind of air pump being used

You really don’t know how A/C works do you.
 
When painting in the home you can put a large box fan in the middle of the opening of one window, blowing from the outside into the room you can close the window on it to hold it in position with a rolled up towel on it (stops the glass rattling too). You don't need to seal around it, it will act like a bit like a venturi and pressurizing the room.
Then setup your booth box, plastic tub ect. in another window made from core flute, card board ect.(used house for sale or political signs and gaff tape) Now you only to need to, reasonablly seal around the booth.
( Make the booth the same surface area or larger of the fan. The width of the window is a good idea but not to big) Then at the back of your booth you can use one or 3 layers of wadding as a filter (wadding is avaliable from frabic shops) now close all doors into that room and put draft snakes under the doors or rolled up towels, close any A/C vent in the roof or floor.
Now you need to check around the window your painting in. Is not above a car, down stairs window A/C, neibours window "you get it" "you will spill paint inside your booth".
Wadding, filters about 25 to 40% per layer of wet paint particals, 80%+ of dry particals will go straight through along with solvent vapors so having it above or near the kids room, playground other windows that are not closed is a bad idea. So for $20 plus dollars you are on your on your way.. i have more tips on it but this is to long aleady.
This isn’t very feasible in my situation as it will and does cause my central air to run more often than it should. I have tried this a few times when painting polycarbonate RC bodies using solvent based paints on rainy days. The box fan I have works great for fume extraction without blocking off the sides but there is the A/C issue as well as having to remove the window screen just to paint. Another issue I live in the sticks so anytime I have to take a screen out then I’m getting lots of unwanted pests inside especially during hot humid days.
 
Back
Top