[GreenKeys] Cleaning agents

[Steve Schlink]

After 30+ years of metal "cleaning" including abrasive blasting, acids, 
solvents, electrolysis  etc. here are my conclusions based on results, 
cost, mess, etc.
Below comments are mainly for steel/iron:

If the item is greasy, I use Varsol with Gunk concentrate added to make it 
miscible in water. Brush it on, soak, hose it off with hot water. Pressure 
washer is good. If the humidity is high, dry with compressed air, or a 
vacuum cleaner hose reversed to blow high volume, low pressure warm air.

As someone already mentioned, Kano Labs products are great. The main 
product is Kroil. Basically it does what Liquid wrench says it does but 
doesn't. Their Kreen is a combustion engine treatment for addition to oil 
or gas to remove carbon, so works extremely well for anything along those 
lines.

If it is just rusty cast iron or heavy steel, sand blast it either in the 
blast cabinet or in the open if too large.
Because of work hardening issues, you really don't want to blast thin steel 
objects.

If it can't conveniently be blasted, then into the garbage can (plastic) 
for the electrolytic cleaning bath. Similar to ultrasonic in results. 
Depending on the amount of pitting, the object may still need a wash with 
Phosphoric Acid (or Coke). The is an issue with hydrogen embrittlement if 
subjected to acid for long periods.

If the item is just lightly rusted, I have been using a product called 
Oakite 33 (phosphoric and surfactants) for about 20 years. If you are going 
to paint, this can't be beat. I bought 4 gal. for $1/gal at an auction over 
20 years ago. Dilute it about 5 to 1.When I recently priced it, I was 
shocked to find that it is now $148/gal. So, I'm now looking for a replacement.

Recently, I have become a convert to Evapo-Rust. It is especially good for 
removing spot rust from plated or blued steel, since it only acts on the 
iron oxides, it won't affect the plating or paint. On the expensive side, 
$9 quart, non-dilutible.

Small or delicate parts go into the 5 x 5 x 5 ultrasonic.

Anything else get scrapped.

Steve