Question about Mineral Wool

bzakes2375

New member
So I want to build my own acoustic panels using Mineral wool like Rockwool. I've come across some people claiming that these products still are made up of the inorganic glass fibers that you can inhale (just like asbestos). Is there an alternative? I don't know if I'd be comfortable building panels that would only contain the fibers with fabric.
 

Ed Fones

Well-known member
I think.

Insulation is made from stone/rock. A natural substance heated until molten and sprayed in fine threads to form the fluffy fine wool type substance of different densities.

Asbestos is a natural rock which is crushed to form whatever it was made into. But it is super fine and sticks in lungs and tissue.

All dust from anything is dangerous if you inhale enough of it. Even flour or household dust. All kinds of dusts from everything are everywhere and you breathe them in daily.

Other alternatives to rockwool are sheeps wool types of insulation or hemp and even cotton toweling. If you could make these dusty then they too would be not great for your health and also these types could have molds growing on them over time. Also not great to inhale.

Studios by their nature are almost sealed. People breathe out lots of water and then this 'can' be trapped in the studio. On organic substances like sheeps wool or cotton, this could start molds growing.

So what is best to use? Rockwool/mineral wool is in most houses and buildings. It is in roofs and walls mostly out of our environment. But a percentage of this dust is still around. In your studio it is behind walls and inside panels which have a covering. Also this type of rockwool is bound together. You could use a very tight woven covering on your panels and even double it.

Watch out for the bus as you leave the studio. :-)
 
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keith.rogers

Well-known member
Wear a good mask, gloves and long sleeves when you are working with the material, and use as tight of a fabric covering as you can find that still "breathes" (literally, test breathing through it). Anything inorganic that lodges in your lungs is going to be unhealthy in the long run, but you are not working with it on a daily basis, and unless you are jiggling and moving the panels around all the time, it's not going to be degrading by itself and spewing out into the room, at least IMO. (Your body's respiratory system is designed to move that kind stuff out of your nasal passages and trachea *before* it gets to the lungs, and is pretty efficient at doing that, given the chance, so keep those parts healthy!)

My little music room is the most dust-free area in the house, and it's got 24 of the batts stuffed into panels, covered (but not tight against the wall) on both sides. It's not going to be what kills me, if it's bothering me at all.

It might be somewhere here that it was noted that you can even cover it in very thin plastic, maybe the thinnest dropcloth stuff you can buy, if you want, without seriously degrading its [sonic] absorption, but I don't know the physics of that. And then, of course, you'd have the microplastics to worry about, because that stuff *will* break down...
 
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rob aylestone

Well-known member
Once you have installed rock wool, after you have some experience off installing fibreglass insulation in roof spaces or walls etc, you will love rock wool and hate fibreglass. My builder is currently stuffing fibreglass into a toilet cavity and he has a mask on and a disposable suit, because those fibres irritate as the little bits of glass stick in your skin, and get onto your clothes. When you work with studios and rock wool, even sawing it gives very little loose fibres in the air, and they sink into little fluffy residue. It doesn't irritate and tends to be much larger particles. rock wool doesn't concern me at all - and if you are the concerned sort, then a mask is a double protection. Rockwool does NOT contain any glass I have ever been aware of - just rock. Fabric covered rock wool has been in use for a very long time, and asbestos has been identified as bad, while fibreglass, loose in your house insulation is not considered bad. rock wool is even less of an irritant and , while a few people have issues with fibreglass, I've never found anyone who has a problem in a studio?
 
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Ed Fones

Well-known member
To be fair though Rob, Rockwool RW3 the acoustic stuff for panels can be very crumbly and is very itchy. Cut with a sharp knife only. It is different than normal Rockwool.

There is another mineral wool insulation called Knauf Earthwool which is normal house insulation and that doesn't itch at all. But nowhere near as good as RW3 for sound.
 

spantini

COO of me, inc.
I use ROXUL Safe'n'Sound. I use a pair of kitchen or poultry scissors which cut through very easily, then I wrap in a cotton bedsheet. There is very little dust when cutting and no problem with dust or fibers when wrapped. No detectable off-gasing.
 

TalismanRich

Well-known member
I wish people would learn to read safety data sheets, and understand that these guidelines are for industrial use, ie someone manufacturing the material or doing installations daily for a living for many years.

The only time that you will encounter any "hazard" is when you are cutting the material. Use a mask to keep from breathing the dust. Stone wool fibers are not even classifiable as OSHA irritants. The stonewool is not classed as carcinogenic like asbestos. Once cut and placed inside the frame and covered, there will be NO migration of fibers to cause the slightest health hazard. You won't encounter any more of an issue than walking across a concrete floor. (hey, that concrete can have asbestos in it!) Rockwool is actually considered safe enough to be used in places like schools and hospital.

As for outgassing. again, there is NO gas release. SafeNSound contains about 3% binder, part of which is phenol formaldehyde resin (aka phenolic resin). If this frightens you, stay away from plywood, anything bakelite, guitars with Richlite fingerboards, printed magazines and about half of the items in your house. Phenolic resins are used EVERYWHERE! It's really useful stuff.

It's probably one of the safest things you can use, plus it's fireproof to boot!
 

jamesperrett

Active member
There is another mineral wool insulation called Knauf Earthwool which is normal house insulation and that doesn't itch at all. But nowhere near as good as RW3 for sound.

As with Rockwool, Knauf Earthwool comes in many different types and Earthwool RS60 is the direct equivalent of Rockwool RW3. I have RS60 in my studio and have installed RW3 in other peoples' studios. They are very similar.
 

Monkey Allen

Fork and spoon operator
I know polyester and spun recycled plastic is formed into bats/ panels which is touted as acoustic insulation. There's no irritant at all from these. Martini Absorb...there's some flow resistivity data etc here:

 

keith.rogers

Well-known member
I know polyester and spun recycled plastic is formed into bats/ panels which is touted as acoustic insulation. There's no irritant at all from these. Martini Absorb...there's some flow resistivity data etc here:

From what I can tell it's only available in Australia. Looks interesting, but also quite expensive.

Looks like you'd need 3-4" thickness to match the materials we typically head to around here, i.e., Safe'n'Sound, or, for folks with good commercial ties, OC703. Absorb HD 75 or HD 100 have numbers in the LF area that are comparable to those products. Specs several pages down here:

 

Monkey Allen

Fork and spoon operator
From what I can tell it's only available in Australia. Looks interesting, but also quite expensive.

Looks like you'd need 3-4" thickness to match the materials we typically head to around here, i.e., Safe'n'Sound, or, for folks with good commercial ties, OC703. Absorb HD 75 or HD 100 have numbers in the LF area that are comparable to those products. Specs several pages down here:

Yeah...and I'm not sure how effective the polyester stuff is below 100/150hz. I got some a while ago...wasn't that expensive as I recall. Prices may be weird these days.

I'd like to get 703 or something like it here in Australia. But it's proven to be a real bear trying to get to the bottom of which stuff to go with. There's glasswool, earthwool, rockwool, fluffy pink stuff, semi rigid pink stuff, fluffy earthwool...and on it goes.

They all have umpteen data descriptions and labels and terms and stats.

When it comes to small rooms like mine...11.8x8.8x8.5ft...the diminishing returns on required thickness would probably mean that I'd have no room to swing a guitar once all the treatment is in place.

It'd be more like a padded cell.

Which, funnily enough, might be exactly what I need after my adventures with room treatment, mix translation, room nulls, room peaks, standing waves etc etc etc.

Either that or I return back to the good old days where I thought that if I recorded it and it successfully played back on my speakers...it was good!

When you realize how amateur things are, you go down a labyrinthian rabbit hole in search of solutions that you might never escape from.
 

keith.rogers

Well-known member
If you are sticking a mic on the grill cloth of your amp, honestly, the room is probably not as important, but when you try to record vocals or acoustic instruments, or monitor your mix on speakers, then the room will make a difference. I just found that treatment (and a bunch in my 11'x11' "cubicle") just saves me a lot of time because I can sit almost anywhere and put a mic in front of the acoustic and get a track, or record some vocal and I know it's not the room that's making it sound bad ;). And, I very rarely have to fuss with a mix that doesn't translate. (Part of that could just be getting more experience, or maybe I don't care as much as I head down the chute...)
 

TAE

All you have is now
Keith said it best earlier...ANYTHING inorganic is NOT GOOD for your lungs as your lungs cannot get rid of it...look up silicosis...silica...sand..which is nothing more than tiny pieces of granite / Rock...glass is also made of.....SAND inorganic Plastic inorganic Potatoes and loli pops Organic If you can eat it, the dust from it is probably not going to hurt you...if not and you are seeing dust in the air from said inorganic product....best practice is, in my best Dr. Ruth voice...Vear a mask and have a good life!
 

TAE

All you have is now
In the RemodHELL I am wrapping up we used both fiberglass and rockwool..The Rockwool I purchased from Home Depot was a nice experience and not itchy..the fiberglass was itchy but not as itchy as it was in the early days...
 

rob aylestone

Well-known member
I've just been to see my friend from the band in the hospice. His lung cancer spread to his brain, so now his sight is starting to fade too. We were laughing about old things, and he reminded me of the time when I went mad when I saw him drilling through wall panels to thread cables through and they were asbestos. We found this really funny when his lung cancer was actually caused by his arthritis and nothing he'd breathed in over the years. The irony was felt by both of us!
 

TalismanRich

Well-known member
TAE, be careful with your definitions. Plastics, for the most part are organic. Organic compounds are made up of carbon, hydrogen and other elements like nitrogen, oxygen, sulfur, etc. Just because it's "organic" doesn't mean it's healthy for you. Likewise, just because something is inorganic doesn't mean its dangerous. Technically water is inorganic since it's only hydrogen and oxygen. In small amounts, many dusts are not harmful. It's the accumulation of years of exposure that causes problems, like black lung in coal miners or cigarette tar from smoking. An hour of cutting some Rockwool panels with a safety knife won't produce enough dust to reach anywhere close to an OSHA reportable level. Once cut and put in the panel, there won't be any further dust release. The "made up of the inorganic glass fibers that you can inhale (just like asbestos)" comment is a scare tactic from the folks making panels out of cotton and plastic fibers. Its a bit like saying that an electric car is non polluting. While technically true in terms of not emitting CO2 or NOx, there was pollution from the lithium mining, the steel manufacturing, and most likely from the electrical generation plant (either coal, gas or nuclear).

50+ years ago, I was dismantling flower benches in greenhouses by sawing them up with a circular saw, then breaking up the piece for disposal. They were made of a material called transite, which is nothing but asbestos fibers in concrete. They had been there from the late 30s when the greenhouses were built, years before WW2.

We also dismantled a boiler that was covered in asbestos insulation. In the 60s, it wasn't a big deal. I even remember having asbestos gloves in chemistry classes for handling hot beakers and flasks. Asbestos was used for years in brake pads which wear down and turn to dust.

I spent the last 10 or so years of my career doing health and safety stuff in plants that handled lots of pigments (dust) and solvents (toluene). We've learned a whole lot in the last 50 years.
 

witzendoz

Senior Member
I Used 50mm, where I need thinker I used 2 sheets to make the 100mm, I bought a lot of it and it was easier to stick to the same thickness for flexibility. Its hard to cut, they cut it to size for me with a diamond blade saw. The accoustisorb 2 can be cut with a knife but is not as good with low end absorption. I did later use some of the 2 around the place as well later in the build.
 

witzendoz

Senior Member
The rest of the answer, it does cost more than fibreglass, however when making traps and gobos you don’t have to cover it. It will absorb 100hz if you build it into a bass trap, just like high density fibreglass. I live in Australia.
 
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