action part cleaning

[John Delacour]

At 00:12 +0100 7/6/08, Allen Wright wrote:

>What's the solution of oxalic acid you mention below (how 
>saturated?) and where does one find this stuff? This looks like a 
>good way to clean old parts....
>
>I enjoyed your damper article - thanks for sharing that.

Hello Allen,

Normally the French polish suppliers have it but here is a link I 
found using Google Shopping:
<http://www.jpennyltd.co.uk/shopping/pgm-more_information.php?id=158&=SID>
It shouldn't really cost that much, but I can't find who I got my 
last lot from, cheaper than that for 5 kg.

A saturated solution is one where the water will not hold any more 
crystals in solution.  A dessert-spoonful in a cup of water would be 
beyond the saturation point I think.  Just use a bit too much of the 
crystals.

As to the poisonous nature of the stuff, use your common sense and 
try not to drink too much of it or let the cat do so.  It can indeed 
be absorbed through the skin, and if you worked a whole day with it 
without washing your hands you'd notice a slight stinging sensation. 
In the article I stress the importance of a good scrub-up after using 
it.  I, my wife and many others have used the stuff regularly for 30 
years, and I never bother with gloves.  Read
  <http://ptcl.chem.ox.ac.uk/~hmc/hsci/chemicals/oxalic_acid.html> --
"Protective equipment : Safety glasses. Gloves are not generally 
required, but if they are to be worn most types of gloves material 
(e.g., nitrile, butyl rubber, neoprene or PVC) are suitable. PVA 
gloves are not suitable for handling oxalic acid or its solutions."

Another piece of misinformation I've found parroted in a few places 
on the WWW is that it "dissolves a layer of dry wood...".  So far as 
I can tell, this is perfect nonsense.

Oxalic acid will also completely remove the black stains caused by 
the contact of rusty iron with wood, for example at the base of a 
check wire.  Several applications are needed, but the effect is 
astonishing.

For its effect on metals, there's nothing like trying it.  On those 
Schiedmayer dampers there was no effect of the damper wires and they 
came up like new with a light rubbing with fine steel wool.  If there 
is exposed iron, the surface will turn a light grey.  It has little 
effect on brass and practically none on nickel.

Here are my recommendations for the super-sensitive and the superstitious:

1.  Don't use shark-infested water to dissolve the crystals.
2.  If you're working in town, especially in America, wear a full 
rubber suit, and an oxygen mask if you need to breathe.  Use an 
umbrella if acid rain is forecast.
3. Scrape some barrier cream from the palm of the hand into the nails 
and round the cuticles before working.  If you want further 
protection and can afford it, use a small amount of silicone barrier 
cream on the hands.
4.  Wash the hands and nails thoroughly after use.
5.  Don't leave it in a dish where animals can get to drink it.


JD

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