Airbrushing with acrylics in a Spray Booth

[sbarnby71]

Mornings folks,

 

I recently bought a portable spray booth, the ones with the flexible hose you shove out of the window.  It's a bit of a hassle having to shove it out of the window because of where I spray and other factors, so I was wondering as I only spray with water based Acrylics could I just make another filter to sit at the back of the unit using foam filters and maybe filter papers you'd use in a kitchen extractor and allow it to re-circulate into the room.  As there are no nasty smells from the acrylics and they are mixed with water, would it be safe?  Has anyone tired it or does anyone know a bit more about when the paint is atomized is it harmful (and I'm sure I'm not the only one who has licked the end of a paint brush to re-shape it over my 30 years of doing the hobby)?

[andes]

I don't use a spray booth at all. If I'm in a long priming session, I'll wear a paper mask to protect my sinuses. I put down some cardboard to cover my desk and shoot at will. The overspray dries in the air for the most part, so I just wipe up the resulting dust with a damp rag and a bit of kitchen detergent every now and then. Note that I have a dedicated hobby room -- I wouldn't be so cavalier if I was painting in, say, the living room. YMMV

[Lucien Eilam]

All I use is a spray hood to contain any overspray, and a light dust mask to avoid inhaling any of the backwash.
 
With the volumes and pressure of airbrushing miniatures, you’re not really creating clouds of paint droplets that will linger in the air, and none of the portable spray booths I’ve seen create enough airflow to make a practical difference to airborne paint anyway. Gravity and momentum is a lot for a small desk booth to counteract.
 
It won’t do any harm running the extractor, and a filter should catch any paint particles that make it that far, but I’d be surprised if much did.
 

does anyone know a bit more about when the paint is atomized is it harmful

 
There may be brands/ranges with exceptions, but typically the pigments are inert and non-toxic. Pretty much the only way most water-based acrylics could harm you is if you inhaled airborne particles and your lungs were unable to clear it out, causing something like pneumoconiosis.
 
In practice, a healthy person’s lungs would expel it just fine. Dust inhalation diseases are associated with working a lifetime in heavy industry, not painting toy soldiers. You could airbrush tens of thousands of points of Space Marines, even with no mask, without fear of triggering it.

 

The biggest threat to your health remains your partner catching you leaving a frame of Balthasar Gold on the dining table.

[UtariOnzo]

The vast majority of acrylics are non-toxic, however anything atomised carries some level of risk to inhalation. Generally low amounts of exposure carries less risk, however it's still good practice to take precautions.

In terms of using a spray booth without the extractor, the filter itself will help with reducing the amount of overspray dust, especially if you're adding some more in. I would recommend a paper mask at the least on top of that, just for the added safety, but as someone who does work in environments where dust is a major factor, so I lean on the side of cautious just due to the accumulated risk between work and regular airbrushing at home.

[sbarnby71]

I had the bits to make the new vent, so did a test with it:

That's a 125mm reducer ring (as the vent on the unit is 125mm) going in a 100mm Louver Vent with a small piece of 100mm pipe between them.  I had some foam lying around, so cut a circle out to stuff into the pipe and then I would add the cooker hood grease paper (which I'm waiting to be delivered) inside the louver grill. 

 

Attached this and ran the booths fan to feel how much air flow and it's almost nothing as the foam is too dense, so not sure if that's a good thing or not if the air can't pass through the foam.  I'm wondering if the air can't pass through the foam then it has to go somewhere, so could it be being pushed back through the extractor?  I'm going to try it again when I have the cooker hood paper and see how that works just on it's own. 

[Firedrake Cordova]

I've never used a spray booth (I airbrush outside), so please bear that in mind when reading the following ...

 

With airbrushing water-based acrylics, the main issue is particulate overspray (aka "small bits of paint") - not only can this make a mess, but it also can be not that good for you if they get in your lungs (I don't think anyone wants aluminium filings in them :P). For controlling this, I'd imagine the standard filter on the spray booth would do the job.

 

The other issue is any chemicals you may be using -  for example, I found that the first couple of times I used Vallejo Airbrush Cleaner, I felt a little light-headed. Whilst you could worry about filtering it out with the spray booth, I'd recommend getting a cleaning pot instead.

 

Personally, I'd avoid putting a filter on the exhaust side of the fan - generally fans designed for high airflow don't push it that well (low static pressure), so you're likely to impede their performance.

[Arkhanist]

Spray booths are mainly to provide a slight negative pressure when spraying paint with organic solvents, e.g. oils or some cleaning products, so you can help vent the small amount of VOC hobbyist levels of spraying generates - so it doesn't build up in your workspace as much. It's still worth wearing a respirator/half mask which can filter organic vapour when you spray oils etc, as you will still get some hanging about your workspace. For cleaning products, just spray them into a cleaning pot with a filter.

 

Straight acrylics generate no VOC vapour (being as the solvent is only water), only the particulates as discussed above, so there's no need to vent outdoors. The negative pressure will help a bit to contain dust, but frankly I've stopped using mine with acrylics long ago as the effect was pretty minimal. I just put down angled newspaper and spray onto that, while wearing gloves to hold the model. Healthy lungs should be able to expel small amounts of acrylic particulates without issue (the plastic is non-toxic per-se), but it's still worth considering wearing some sort of dust mask, as you would when doing DIY or otherwise generating dust as you're pretty close to the source. I admit I don't tend to bother if I'm only going to be at it for 5 minutes, but I do use my respirator when spraying non acrylics (mostly varnish) or for a longer session.

 

Assuming you want to carry on using the booth, that foam is way too dense, you want a much lighter piece of foam or filter, ideally source side as firedrake cordova says. I'm kinda surprised your booth didn't come with one, all the ones I've seen had foam (usually blue) on the source side to protect the fan itself. Cooker hood filters are a good source if your booth didn't come with one; the greasepaper one you have on order is worth a try!

 

Edit: the only toxic acrylics I can think of are yellows/reds made with cadmium, and they're pretty rare these days, especially in acrylics intended for airbrushing. Just check the pot for a toxicity warning for yellows/reds you intend to spray (specifically, a "do not spray" warning). Vallejo used to have some, but they're long gone.

Edited May 12, 2021 by Arkhanist

[sbarnby71]

Spray booths are mainly to provide a slight negative pressure when spraying paint with organic solvents, e.g. oils or some cleaning products, so you can help vent the small amount of VOC hobbyist levels of spraying generates - so it doesn't build up in your workspace as much. It's still worth wearing a respirator/half mask which can filter organic vapour when you spray oils etc, as you will still get some hanging about your workspace. For cleaning products, just spray them into a cleaning pot with a filter.

 

Straight acrylics generate no VOC vapour (being as the solvent is only water), only the particulates as discussed above, so there's no need to vent outdoors. The negative pressure will help a bit to contain dust, but frankly I've stopped using mine with acrylics long ago as the effect was pretty minimal. I just put down angled newspaper and spray onto that, while wearing gloves to hold the model. Healthy lungs should be able to expel small amounts of acrylic particulates without issue (the plastic is non-toxic per-se), but it's still worth considering wearing some sort of dust mask, as you would when doing DIY or otherwise generating dust as you're pretty close to the source. I admit I don't tend to bother if I'm only going to be at it for 5 minutes, but I do use my respirator when spraying non acrylics (mostly varnish) or for a longer session.

 

Assuming you want to carry on using the booth, that foam is way too dense, you want a much lighter piece of foam or filter, ideally source side as firedrake cordova says. I'm kinda surprised your booth didn't come with one, all the ones I've seen had foam (usually blue) on the source side to protect the fan itself. Cooker hood filters are a good source if your booth didn't come with one; the greasepaper one you have on order is worth a try!

 

Edit: the only toxic acrylics I can think of are yellows/reds made with cadmium, and they're pretty rare these days, especially in acrylics intended for airbrushing. Just check the pot for a toxicity warning for yellows/reds you intend to spray (specifically, a "do not spray" warning). Vallejo used to have some, but they're long gone.

The booth does come with an internal blue filter, my only reason for added the extra was I was trying to avoid using the vent hose, so figured adding an extra bit of foam would catch any final particles that made it through the main blue internal filter.  But you're right the foam I'm using is too dense.

[sbarnby71]

Tried adding the grease filter paper to the vent at the back and the flow of air coming out with minimal (big drop from no paper filter), so I think I'll just leave this off for now, maybe put some paper or carboard near it to see if I'm getting any particles of paint coming through when I'm using it.  Thanks for all the advice, I think just a dust mask should be fine.