Rust Removal/Conversion

Subj:	Rust deactivator
Date:	96-11-09 01:47:48 EST
From:	(Paul Pavlinovich)

I'm thinking of painting the inside of a hopper & the water jacket on one of
my engines with a "rust deactivator" - these things have a reaction with the
metal and form some kind of iron alloy which is impervious to rust (so the
instructions say) - anyone used something like this on an engine? Any thoughts?

Regards
Paul
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Subj:	Re: Rust deactivator
Date:	96-11-09 10:54:21 EST
From:	rskinner@A.crl.com (Rob Skinner)

At 06:02 PM 11/9/96 +1100, you wrote:
I'm thinking of painting the inside of a hopper & the water jacket on one of

Hi Paul, 
I've had good luck with the stuff.  I had an old engine that I was turning
into a flower pot.  I hit it with the wire wheel, slopped on some of the
rust deactivator,shot some paint on it, filled it with flowers, and set it
on the patio.  That was several years ago, and there is still no visible
evidence rust.  

Rob Skinner  rskinner@a.crl.com
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Subj:	Re: Rust deactivator
Date:	96-11-09 14:16:16 EST
From:	Jochen.Nimtschek@rz.ruhr-uni-bochum.de (Jochen Nimtschek)

Hi Paul,
the process you are speaking about, is a procedure to phosphate the 
surface of a metal on iron base. The phosphating can be done with 
zinc or manganese. Zinc is easier to handle, manganese gives better 
results. Normally the process runs at temperatures of ca.75 Celsius 
(zinc) or ca.92 Celsius.
There are derivations available that work at ambient temperatures.
Both the hot working and the ambient working chemicals perform an 
excellent supposition again rust and for painting.
I have made very good experiences with that.

Best regards
Jochen
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Subj:	Re: Rust deactivator
Date:	96-11-10 07:32:45 EST
From:	kali@nor.com.au (Kali McLaughlin)

This is great information Jochen.
I presume this phosphating is the principle of 
*Ferropro
*Phosporic acid
*naval jelly & other variously trade marked "rust converters". 

My question is where do the zinc or manganese ions come from? are they
dissolved in the transparent agent, or do they migrate from the under coat
that you next apply in the cold process one uses on big structures?

My interest (apart from engines) is in windmill towers. We have a very wet,
but not salty climate and I have found that "cold galv" under coat works for
up to twenty years on mild steel outdoors.

I have been experimenting with fish oil, XTROLL, linseed oil, in combination
with cold gal in order to seal crevices and this seems fine.  Tar however
has been a complete failure.  Moss grows under it and lifts it within a year!

My house is ferro cement and my theory was that the free lime in the mortar
would prevent rust in the mesh by keeping the Ph too high. This theory was
basically correct and after twenty years the mesh is still shiny where I
have had to bash holes for pipes etc. My mistake however was in thinking
that the framing steel inside would be safe. No such luck!  The various
pores in the render leaked into the internals which proceeded to rust.  I
tried a good dozen sealing compounds before I found Cold Gal paint -
basically zinc powder in an oily carrier and with acetone as solvent.  The
house stopped leaking and the frame stopped rusting.  The reason was not
because of any complicated ion exchange in this case, but simply because the
moss could not put its roots through the paint because of zinc toxicity.
This is my theory anyway!

Kali
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