How To Clean Acoustic Foam

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Cleaning Auralex foam?

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In addition to some Safe 'n Sound bass traps I made, I recently bought 6 used Auralex 2x4 panels to treat my room.

The panels are 5 - 10 years old (and surprisingly intact). They were unfortunately stored in a closet where animals had access, and are a little smelly.

I was thinking of lightly spraying them with a vinegar/water solution, or possibly using some type of pet odor remover. I'm a little wary of the latter, however, as I'm not sure how it might affect the foam's effectiveness.

Any ideas?

Gear Guru

I would send the company an email and ask them. They should give you customer service even if it is used. Let us know what they say.

Odors are admittedly difficult to get out of foam, and it's not really a material you can wash, wring out, dry, and get back to brand-new. In an ideal scenario, you could give it time to air out in an a space like a garage with some decent fresh air turnover and then give it a light misting (emphasis on light) with a Febreeze-type product. A couple of rounds of treatment couldn't hurt either, provided you're making sure it's completely dry before spritzing it again. If it's a fairly strong scent though, you probably won't get it to the point where it's no longer noticeable unfortunately.

Gear Maniac

Sometimes odor is caused by bacteria. In that case roll the foam and freeze it. Surfers use this trick for their wetsuit boots, whose odor is surely stronger than that of your foam

Hydrogen Peroxide is a decent cleaner
Never have used it on acoustic foam, so test it first.
Might also want to do it in a well ventilated area.

Lives for gear

Once I had some smaller pieces of foam, they were supports from inside a microphone case (pretty much the same type of foam as acoustic foam)... they severely stank of cigarette smoke. I simply soaked them in hot water mixed with laundry detergent... and swished them around and squeezed them to make sure they were fully saturated with water and detergent... then squeezed out the excess water and put them out in the sun to dry. Once dry, there was not even a tiny trace of the cigarette odor, it was completely gone. Foam looked and smelled clean, like new.

I don't see why you couldn't take your foam outside, on a patio or whatever, and completely hose it all down. Then dump buckets of hot water, mixed with some type of detergent, laundry detergent or perhaps another all-purpose, anti-odor type solution... they make good odor detergents for rug cleaning too, go to Home Depot and ask, they have it. Soak the foam with this stuff, then squeeze the foam to get the now dirty water out, then rinse with the hose, then repeat a few times... then lay out in the sun to dry. Side note.... try to do this in warmer weather on a clear, sunny day. This should get your foam clean.

Though of course, if the foam is tattered and starting to flake apart from age, then squirting it with a hose etc might cause it to come apart even more. But, if the foam looks and feels "ok", then hose away. Finally, if the foam is to the point where you can't even hose it down, then it's not even worth keeping. I have Auralex foam here that is definitely over 10 years old, it's in excellent condition, not flaking at all, I could squirt this stuff with a garden hose all day long and it wouldn't hurt it.

Speaking of my old Auralex foam, some of it was in a slightly musty basement room for a while and took on a musty odor. I simply aired it out, outside, for several days, in the sun etc, and after that the musty odor was totally gone.

So, in sum, you could start by trying to just air your foam outside for several whole days. Sunny, windy days are ideal. If that does not prove to noticeably reduce or get rid of the objectionable odors, then whip out the garden hose and get to work.

Quote:

Originally Posted by 666666 ➡️

Once I had some smaller pieces of foam, they were supports from inside a microphone case (pretty much the same type of foam as acoustic foam)... they severely stank of cigarette smoke. I simply soaked them in hot water mixed with laundry detergent... and swished them around and squeezed them to make sure they were fully saturated with water and detergent... then squeezed out the excess water and put them out in the sun to dry. Once dry, there was not even a tiny trace of the cigarette odor, it was completely gone. Foam looked and smelled clean, like new.

This would definitely be the most effective method since it's an all-out wash cycle essentially, but there are two reasons I'm usually reluctant to suggest it.

The first point, and the main one, is that it's difficult to fully dry out foam, no matter how much it gets wrung and air-dried. I'm not saying it isn't possible, but it's not something that's easily done since the material is so inherently absorbent. The last thing a small, sealed space needs is almost-dry materials mounted on the walls begging to mildew. The other factor is that it's possible to wash out some treatment products like fire re.tardants that may not have been added during the foam's formulation. This is generally only a problem with low-quality products, but still something to be aware of. If you've tried everything else and the foam is still unusable, putting it through the equivalent of a laundering hell-cycle can be an effective last resort, but you run the risk of ruining the materials. Of course, that's less problematic if it was going in the bin anyway. Trying to do as little as possible and escalating as needed is generally the best way to go though, sort of like if you need to light a candle, try a match before a flame thrower

Also, as an aside, if you're looking to air out or freshen up some panels or tiles, be aware direct sunlight can have a yellowing effect on lighter colors, which you've probably seen in other foam products like old cushions. Fortunately, treatment is usually darker - charcoal and deep purples, reds, greens, and so on - these aren't as susceptible to yellowing.

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Quote:

Originally Posted by CarloBadalamenti ➡️

.... it's difficult to fully dry out foam, no matter how much it gets wrung and air-dried...

Totally agreed. It surely is very important to fully dry the foam before installing. And drying soaked foam is definitely a bit of a chore... but it can be done if you have two hot, sunny days and a good deal of patience.

I once had to fully launder a pair of velour (with foam-like material underneath) car seats after a cat pissed all over them ... and another time when a drunk friend puked all over one of them! I removed the seats from the car, fully hosed them down, fully saturating with water, then detergent, over and over and over... and then it took several entire days in the hot sun (on clear, mild, dry days) for them to fully dry. Every hour or so I'd rotate them around so the sun would be hitting at all angles. They finally did fully dry and were fine. Odors completely 100% gone... zero mold or mildew issues... (and I have a VERY sensitive nose, I can sniff out a single mold spore at 10 yards! ) Was successful but it was indeed a chore.

If you soak foam sheets with water, once done, lay them on a clean, flat, stable surface (could be a piece of clean, clear plastic sheeting, on a concrete patio or whatever) and literately use a large rolling pin if you can find one to roll / squeeze out as much water as possible. I actually do this when I wash the thick, shaggy area rugs my wife insists on using in the house... rolling pin works great.

THEN, you need to figure a good two days in the hot sun... I'm talkin' beaming, blazing summer sun, from 8am to 6pm, all day. And keep them suspended if possible while drying as opposed to laying flat on the ground. When I wash rugs I usually lay them on an old, MESH ironing board so they're exposed to air on both top AND bottom sides. They likely will dry in one full day (assuming good, hot sun), but to be safe, figure two days. This general procedure will definitely dry the foam 100%, through and through... but again, it's a chore.

Finally it starts to come down to, is it WORTH it? You might be better off tossing the old, stinky foam and just buying a few new sheets... and save yourself the trouble. Plus there's the other potential issues, pointed out by CarloBadalamenti, that could give you additional headaches.

Lives for gear

Lots of great advice. Leaving them out in the open is a good idea; no idea why I didn't think to do that, especially living in FL! We'll definitely have a sunny day or two this week.

I don't think they're smelly enough to warrant washing them - I read about doing that, but like Carlo suggested, I'm kinda wary about washing off the fire ******ants and/or decreasing the foam's effectiveness.

I'll probably buy new foam or build 2" panels eventually, but this is some of my first treatment, and I got six panels for $100, so I'll make do for now. The smell isn't terrible, either, just a little noticeable.

Thanks guys!

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Got a response from Auralex this morning:

Quote:

Because of the properties of the foam and with it being an open cell material, we strongly advise against getting it wet. Any moisture trapped in the cells can mold and create more cleanliness issues, although will not affect performance. For cleaning the foam you can dry dust or use an upholstery attachment on a vacuum.

Lives for gear

Only problem, if you have something like cat pee in your foam, dry dusting or mere dry vacuuming is not going to do anything at all.

But, an upholstery wet vac might be effective... the type that sprays a fine mist of water / detergent into the upholstery and then immediately sucks the water back out. As long as the source of the offending odor is not too deep, this might work.

Again, I can understand everyone's concern about getting foam wet. Indeed if you do not take the proper measures to fully dry it, you WILL have problems. But, my "argument" is, if you wet it, just make sure you DO fully dry it (which takes patience and effort). Then you won't have any issues.

Auralex of course cannot assume that the average customer is going to "properly" dry the foam after wetting it so it makes sense for them to discourage the idea of wetting it. Plus they'd also be happy to have you throw away your old stinky foam and buy new foam from them.

Quote:

Originally Posted by 666666 ➡️

Auralex of course cannot assume that the average customer is going to "properly" dry the foam after wetting it so it makes sense for them to discourage the idea of wetting it.

This is the exact reason I would never suggest getting open-cell foam wet as well, unless it is, without a doubt, going straight into the trash otherwise.

In theory, it can be possible to get it dry, but there are just so many externalities involved, it's impossible to expect Person A to do everything as thoroughly as Person B, and so on and so on. It's just one of those slippery slope situations we're all too familiar with.

Lives for gear

I would have a serious concern about leeching of the flame retar-dant they used on the product........

If anyone decides to wet clean these products then I would suggest that you test them afterwards to verify they are still FR........... they should not sustain fire after the flame is removed - if they do then lose them immediately as they do not belong in your space.

Rod

How To Clean Acoustic Foam

Source: https://gearspace.com/board/studio-building-acoustics/903517-cleaning-auralex-foam.html

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