[Jibara]

Yes.

http://www.woodsymposium.wsu.edu/agenda/documents/Malmbergabstract.pdf

http://www.merriam-webster.com/dictionary/urea

[Bob in St. Louis]

Wow...  ...How do they come up with this stuff?  (No need to answer that).
That's just gross.

Bob

[dmiller]

cow urine contains urea, all urine contains urea
but as it difficult to follow cows around collecting urine and people wont cooperate
urea in industry does not come from cows, as far as I know it's from petrochemical. Urea is one of the two forums of Nitrogen in fertilizer.


For OB, laminated OB up to the weight I can handle - 1.5 to 2.5 inches
box speakers I would only use a solid plywood like baltic birch. I haven't decided about the sound of wood, but I just don't like working with mdf
For OB, mdf can be completely sealed. So the only outgasing should be from the paint.
I never cut MDF in the house.

[JoshK]

For my abbey clone baffles, I just glued 3/4" baltic birch to 3/4" mdf.  Simple mix of both.   1.5" MDF is heavy!  BB is light, so half/half is much lighter than all MDF.

After working with BB on this project, I may never use MDF again.  The BB is expensive, but it makes so much less mess and the dust isn't nearly as irritating.

[panomaniac]

Yeah, I know a few carpenters who won't touch MDF - can't. The dust and the fumes really hurt them.  Too many years working with the stuff.

It is nasty, but if you work outside and wear a mask, it isn't too bad.  Unless you do it for a living.....

[JoshK]

Don't know if you can find this or equivalent in the states, but this ought to dampen a baffle.

http://www.korff.ch/E/hawaphon.htm

[Bob in St. Louis]

That's very cool, but can't find a price.