Larry Gagnon wrote:
On Sat, 16 Jul 2005 00:30:33 +0000, RadioGuy wrote:

Howdy:

Its been a common practice with me to finish the aluminum surface of a
chassis or box with an immersion into a caustic solution followed with a
coating of clear acrylic spray---I like the satin finish it produces. I
normally use lye that I regularly found on the shelves of our neighborhood
hardware stores. However, I've been having a harder time of finding the
flaked lye that I have used over the years for that purpose. I have used
'Lewis Red Devil Lye' that I found at Ace Hardware.
[snip]

Am I correct in understanding that TSP, also called Sugar Soap (the stuff
used by many to wash walls before painting) is essentially mostly lye? If
so that is quite a cheap source you might want to consider.

TSP is Tri-Sodium Phosphate; lye is Sodium Hydroxide. They're different
compounds with different properties.

Sodium Hydroxide is incredibly nasty if mishandled: the human body does not
handle strong bases well, and Sodium Hydroxide eats flesh with terrible
avidity. It's really, really easy to lose meat or an eye to a drop or three
in the wrong place. I wear long gloves, a plastic apron, a long-sleeved
shirt, goggles _and_ a face shield whenever I have to work with it.

TSP, while much less nasty, is still nothing to play with. Google for the
Material Safety Datasheets (MSDS) on both.

--
Before long, Microsoft will attempt to patent the alphabet (hoping we'll
have to pay royalties to use our keyboards and keep their stock solid).
-- Phil Paxton