On Sun, 3 Jun 2007 16:48:12 +0000 (UTC), Peter P. wrote:

>...
> I also found a large desiccant bag
> marked 'activated bentonite' in a packing carton once. I did not know that
> bentonite could be used as a desiccant (only as absorbent). Imho really wet
> bentonite behaves like wet clay ... or mud. In fact it *is* a kind of mud. 

I seem to remember it's used as a slurry in mining operations - perhaps as a coolant for drill bits, or to wash wanted minerals from the mining face?

> I am
> not sure what would happen if the Tyvek bag would tear with wet bentonite in it
> next to a piece of equipment that is supposed to be kept dry. At least silica
> gel does not become any less silica gel when wet. It's still a solid.

First, I think you'll find tearing Tyvek is incredibly hard to do - certainly wouldn't happen in the ordinary course of shipping and storage.  And if it was 
damaged by something intruding into the packaging, I think the valuable item itself is likely to be severely damaged anyway!  :-)

Secondly, I believe Tyvek acts like Goretex - it allows water vapour to pass through it, but not actual water droplets, so even if it got wet enough to 
develop a slurry I don't think it could escape if the bag wasn't compromised.

Cheers,


Howard Winter
St.Albans, England


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