Sciencemadness Discussion Board

Glass Wool

JJay - 7-11-2015 at 20:22

I am in need of some glass wool for various purposes. I've seen lab grade glass wool for sale a few times, but the price seemed outrageous. I can cheaply and conveniently purchase fiberglass at a home improvement store... is there any reason I can't just use fiberglass as glass wool...?

Deathunter88 - 7-11-2015 at 22:23

Quote: Originally posted by JJay  
I am in need of some glass wool for various purposes. I've seen lab grade glass wool for sale a few times, but the price seemed outrageous. I can cheaply and conveniently purchase fiberglass at a home improvement store... is there any reason I can't just use fiberglass as glass wool...?


Lab grade glass wool is expensive because they are washed multiple times with mineral acids to remove impurities. Fiberglass should work just as well in most applications.

JJay - 7-11-2015 at 22:34

Interesting... one thing I would use it for is microscale filtration with a pipette or syringe. Perhaps I should wash it in acid first....

UC235 - 7-11-2015 at 23:26

Fiberglass insulation at the hardware store is spun recycled glass (probably) chopped and sprayed with adhesive and dye before rolling into a convenient shape. Lab quality glass wool is a fluffy relatively long-stranded clean white material made from borosilicate glass and nothing else. I hate working with it. It doesn't compress well so you need to ball up a fairly large amount and jam it in place.

Plain old cotton balls work for most things that aren't strong acid or bases or require lengthy exposure. The texture is also much better.

JJay - 7-11-2015 at 23:49

I have been using polyester polyfill, but I'll probably switch to cotton if I have to put through any solvents or extreme pH mixtures.

[Edited on 8-11-2015 by JJay]

S.C. Wack - 8-11-2015 at 12:31

Insulation is made with a formaldehyde resin binder. Fiber sold for mixing with Bondo or gypsum/PVA should be cleaner. I don't think that the original glass (OG) wool made by Owens-Corning (US2121802) that was the standard for lab or insulation usage was made with organics at all, or is made by anyone these days. The original Pyrex wool was bulky, barely-more-than-random thin loose rolled sheets, rather than the rope Corning sells now, which is not made by them any more; looking at the MSDS, it's also contaminated with organics, in a different way than the insulation and can presumably be washed.

[Edited on 8-11-2015 by S.C. Wack]

Artemus Gordon - 8-11-2015 at 13:29

You can buy 50g of laboratory glass wool for $8.49 from Elemental Scientific.