space manufactuof acrylic vs. glass?

> Seems like most all of the peer-reviewed space
> habitat designs have assumed use of glass. I strongly suspect this is
> because when we're talking about needing something by the square mile, we'd darn
> well better be talking about the cheapest substance with the simplest materials
> processing which can do the job.

That sounds sensible, but I'm having trouble backing it up with figures. A square foot of 0.5" acrylic sheet is $10.50, which works out to about $8900/m^3 [1]. A 15 mm rod of clear fused quartz glass is $26.70/foot, which works out to over $495000 (yes, half a million!) per m^3. A case of Pyrex glass rods is $111, and works out to $22000/m^3 -- a lot cheaper than fused quartz, but still about 2.5 times more expensive than acrylic.

Of course, I'm sure there are cheaper sources for bulk glass, but then that's probably true of acrylic too; I just quoted the first source I could find of sheet/bar/rod stock.

On the other hand, I have a vague idea how glass is made; I have no idea how acrylic is made and whether it would be a good fit for space processing or resources. But if the production process were a lot more expensive (on Earth) than that for glass, you wouldn't expect to be finding it so cheap.

I wonder if perhaps acrylic wasn't well known in the 1970s, so glass was assumed, and now it's just a matter of habit?

Best,
- Joe

[1] http://www.scicominc.com/plastic_sheet_stock.htm
[2] http://www.waleapparatus.com/walestore/SearchResult.aspx?CategoryID4

Joe Strout -- joe@...