From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: TSP:  Explosive- or not
Date: 22 Jun 1996 07:46:12 GMT

In article <mbgraney-2106961519460001@news.earthlink.net>,
mbgraney@earthlink.net (Nobody) says:

>In article <4qck7a$oc3@newsbf02.news.aol.com>, neever@aol.com (NEEVER) wrote:
>
>> TSP:  Tri-Sodium Phoshate.  I use it to loosen paint on old building.  Is
>> it of any use to a pyro?
>
>Yes, notice how it says do not mix with Aluminum foil?  Well Make a really
>concentrated solution and add a lot of aluminum foil.  The gas released is
>Hydrogen.  If you're wondering why it works it's because Aluminum has a
>charge of 3+ as an ion and TSP is Na3PO3.  One Al ion takes the place of
>the three Na+ ions to form AlPO3 an 3 Na.  The three sodiums react with
>the water to make NaOH and H2.
 
Another way to look at it would be to ignore the presence of the 
sodium ions and just look at PO3(-3) as a fairly strong base:

PO3(-3) + H2O <-->  HPO3(-2) + OH(-)

Al + OH(-) + H20 --> AlO2(-) + 3/2H2

Then depending on pH:

AlO2(-) + H3O(+) <--> Al(OH)3 <--> Al(+3) + 3OH(-)


Al(+)3 + PO3(-3) <--> AlPO3(s) 

Jerry (Ico)