Spray paint extractor fans

I need to move my airbrush set up from our garage into the house, so I’m looking at extraction / ventilation options. One thing I notice with some of the ready made booths is the warning not to use aerosol sprays with them. I am guessing this is due to flammable propellents, and perhaps the higher volume of gas from an aerosol compared to an airbrush, where the volumes are pretty small. Possibly they simply don’t have sufficient extraction rate, and possibly there’s a fire risk from spraying flammable droplets at an electric fan. Also, despite the small volumes from an airbrush, substances like Mr Levelling Thinner, cellulose thinners, etc. are flammable.

Does anyone have any thoughts on the suitabilty of such booths in these scenarios?

I was looking at ATEX rated fans such are explosion proof, but obviously they are more expensive - though not massively over the cost of an off the shelf spray booth. Clearly these are intended for high volumes associated with car paint spraying etc, so really are over the top for modeling. I see the flow rate from one of the best selling airbrush booths is 4m³/minute, while a popular ATEX fan on ebay (weight 14kg, £180…) is 55-62m³/minute. Smaller and cheaper models seem to be available via the likes of Alibaba. I bet these are really loud in comparison, but that’s a massive airflow that would cope with anything you could throw at it in a modelling situation, and be safe to use from a fire situation. Is this the kind of thing that you just can’t sit anywhere near due to the noise and airflow? I mean it’s not sucking like a black hole or a jet engine, right??

I have seen examples of home made booths using PC cooling fans, which are brushless, and therefore theoretically less of a fire risk, but the airflow on them looks tiny and inadequate. There are also fans for bathroom extraction, intended to fit in roof spaces with long ducts, which look powerful and quiet, but obviously aren’t ATEX rated.

Anyone have thoughts, observations, please?

I use Humbrol thinned with balsam turpentine for airbrushing and just for the fun of silly experimentation I aimed out the window and used a cigarette lighter to try and set the spray on fire.
Didn’t work. No cool flame thrower for me.
Lighting the spray from aerosol cans is no problem since the drive gas and/or the content is usually combustible/flammable.

Brushless DC fans do not have coil brushes and therefore do not generate sparks → no ignition source.
Spraying them full of solvents could possibly wash away the grease from the bearings and eventually ruin the motor.
Many DC fan motors are also brushless and do not generate sparks
Another option is tangential fans where the motor is outside the airflow.
Similar to this one:
image

Even if the fan motor isn’t brushless the contaminated air will flow past the motor casing so fast that it will not enter the motor.
The sheer amount of air moved by the fan will also dilute the puny airflow from the airbrush down to well below combustible levels.

Thanks… In theory, at least, I agree that the volumes are probably too low from an airbrush to cause a problem, though I’m slightly surpirsed you couldn’t set fire to the spray.

But what about being able to use aerosol cans?

Tangential… I haven’t seen that term in the context of fans, but I have seen centrifugal, which also seem to be brushless, I’m not sure if that’s the same thing.

DC fans do seem to generally have a pretty low flow rate, unless in looking at the wrong ones - they mostly seem to be for cooling purposes rather than extraction.

250 cfm should be plenty many times over
Just one example:
https://www.cuidevices.com/catalog/thermal-management/dc-fans?q=5iv21h

Tangential

Centrifugal
image

Axial

Using aerosol cans would probably pose stricter requirements on keeping the electrics
outside the airflow. BUT, brushless motors do not generate sparks.

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Pace paint booths work very well and are high quality. I have the middle version. My only regret is not gets a quality paint booth 30 years ago.

Talked with the owner before ordering several years ago due to the same questions, First Circle because lacquer, naptha, xylene & naptha etc based & thinned hobby paints are my preference airbrushing. Please feel free to call Pace and discuss any safety questions. The owner was very candid and knowledgeable. A+++ business in my experience.

Very happy with the Pace paintbooth. With it ducted out the window & running, fumes are very minimal to zero. Fan cfm is ~150, to overwhelm extraction fan in my experience it takes one minute nonstop spraying of thinner to fume the room at a noticeable level. That’s definitely not how I paint or clean airbrush etc.

Running the booth is also handy for:

  1. drying washed models quicker

  2. venting fumes from painted models as they cure or dry

  3. defacto photo booth if using lighted version

Best wishes with your new painting set up

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Pace paint booths are the market standard. They are really incredibly good and affordable.

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Interesting - I saw the Pace items, and it sounds from what you’re saying that they are safety rated, so superior to the items available via Amazon etc. that cost around £80 to £120, also superior in terms of materials (metal not plastic) used in construction. Two problems however are that they’re around $500, and ordering one from the UK would incur prohibitive carriage and customs charges.

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I didn’t think of customs and shipping charges. Any possibility a service like Parcel Monkey etc could do it at reasonable cost?

FWIW - I’ve sent heavy car parts, exhaust manifolds to Norway to help out a friend into Z28 restoration. He found a shipping service that acted as intermediary. I shipped to the service and they took care of getting over across the pond. Took a month or so but it was ~75% less expensive than what UPS/FedEx quoted. This two years ago.

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If you are UK based then I have this one, in fact I’ve had it for almost 15 years now and just changed the filters when needed. Not cheap either but not ridiculous, powerful, reliable and UK supplied so no worries about import fees;

And actually this looks like a newer one and is not quite so expensive, looks nice too;

In fact I would probably have gone for that if it was available back in the day!

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Thanks Wade, yes, as well as the post fee, there’s 2.5% tax, plus whatever handling fees the carrier feels like adding in order to collect the tax. I’ve been burned like that before buying things from the USA, sadly.

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Thanks for this, these do look good, and interesting video - pretty much saying what I suspected about the clones of the cheaper booths available from Amazon etc. Also addresses the issue of aerosols, and I actually like the open bottom section so there’s no lip into the booth.

I’ll have to retire to a dark corner to ponder the potential outlay… I’m still intrigued though by the thought that these booths are about double the cost of one of these:

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There has to be the proper fuel to air ratio for a problem and the flashpoint needs to be low. You will not achieve these parameters with an airbrush unless you were running straight gasoline or alcohol with a lighter. Even then the cubic flow of air might be great enough to prevent it even then.

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I think low production levels always means higher prices, in fact looks like they are manufactured to order. I use lacquer paints almost exclusively and this deals with the fumes very well. Would always be nice to pay less but sometimes the investment is worth it. And the prices are even more inflated after the last few years.

However, it is a decision that deserves much pondering. Good luck!

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239CFM exhaust fan. $32.99. Works great. It actually draws so much air I had to install a dimmer switch.

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Hi Greg, yes, the flow from an airbrush is very small, but I was also thinking about aerosol spray cans.

Colin, that is certainly cheap and powerful. I assume it’s not rated explosion proof, it’s just a standard extractor fan. I can similar items for around the same price with a speed controller included.

Not worried about explosions. The airborne concentrations we generate aren’t anywhere near what’s required to ignite from an electric motor. It’s technically possible, but highly unlikely. For example, your average paint thinner has to have an approximate 6% content in the air to be flammable, which would also leave you dead on the floor from breathing it.

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I watched a fair number of YouTube vids on home made paint booths, and it convinced me of the need to go for a more powerful fan. A number of the videos go through the booth construction process and finish up with a demo of the extracting capability of the fan with some smoke, and looked fairly disappointing - like the smoke vaguely drifting towards the fan.

I also saw some pretty good looking set ups (including a way over the top welded metal booth that did look awesome), one of which went along the lines of, if you can get an atex fan, then you might as well, better to err on the side of safety with your home…

I stalked a few fans on FB marketplace until a reasonably local one appeared and I got that a week ago. 8" fan, flow is 25m³/min. All the used examples I saw were 110v 16 amp (construction site rated) so I also had to get a transformer. Eventually I found a light duty (750kva continuous) one that was clean - most of the available examples are higher rated, so bigger and heavier, and covered in cement, paint and plaster.

I now need to get the rest of it together, but waiting for the room to be changed around before I get the materials. I think it can be positioned directly in front of a window, so not much ducting needed.