Subject: Phosphoric Acid - Do it yourself.

From: [email-masked] (Peter Northway)
Date: Wed, 08 Sep 93 12:02:14 +1300

Reading the recent thread on surface preparation I thought some people 
might be interested in a formula for ruskiller which I use.

This formula was given to me by a senior chemist for a very large chemical
company, (I)ncredibly large (C)hemical (I)ndustry leader, about sixteen years
ago and I have used it successfully since then.

RUSTKILLER

      Phosphoric Acid   25%  (I use 95% food grade, used by dairy companies).
      Alcohol           25%  (I use Methylated Spirits)
      Water             50%
      Washing up Liquid a few drops. (whetting agent)

Yes I know that makes more than 100% with the washing up liquid but the
measurements are not that critical.

I find that it works better if you mix it up one day and then leave it until
the next day to use it. The reaction is exothermic so don't seal the container
tightly, allow for expansion.

Providing you can get a good cheap source for the Phosphoric Acid then this 
mixture works out at a fraction of the cost of commercial Rust Killers.

     Peter Northway        | Disclaimer : This is just my opinion. Well more
  Wanganui New Zealand     | like a tiny ripple in the fabric of the universe.
[email-masked] | Well would you believe just another beer break.