Need to remove rust from cast iron and steel machinery Are there any
reports on best products for this task

Most rust removal products are based on 50% phosphoric acid with about
5% methanol as a reaction moderator.

Kerosene works fine as well.

Some harsh compounds, like muriatic acid, will produce very toxic
fumes when they react with the rust build up. So, if you dare to try
something that strong, do as the label says.... be in a well
ventilated area! (I have only used it outdoors... and sparingly!)

My friend has had fair results using the juce from ordinary automobile
batteries which are about to be junked. I'll guess 10% sulpheric acid.
Somewhat more if the battery is charged just before junking it. This
produces only modest fumes. He has had better luck with 50% phosphoric
acid without methanol. Any kind of acid needs to washed off as soon as
the rust is gone. Some rubbing helps. The metal now needs a protective
coating or it will rust again in Florida's humid atmosphere. My fred
has had good luck with the clear licquid that separates from old water
base paint mixed with about an equal weight of powered zinc and a
small amount of lye = Sodium hydroxide which willreact with the zinc
besides nuetralizing any residual acid. He has several old sash
weights that have been outside in the rain for two years which have
not re-rusted. He says he has another secret ingredient.  Neil

Naval Jelly
http://www.shorechemical.com/Section%207%20Tech%20Sheets/naval_jelly.htm

http://www.jamestowndistributors.com/eserv/eclipse.ecl?PROCID=WEBDISP.WOEB.MAIN&CLEV=5&PLEV=1&QLEV=1&PN=184

Hydrochloric acid is the business on steel castings, girders, engine
blocks or even body panels using a paint brush. I use conc, but
?pickling baths? generally employ a more subtle hydrochloric, nitric,
sulphuric (sulfuric) mix. There are recommendations on the web for
your specific application.

Degreasing prior to pickling is essential. Ordinary washing powder
works well but for aggressive cleaning, caustic soda -- NOT on ally
though.

Trust cautionary notes are superfluous.

Best

My Dad is a hobbyist in refurbishing classic cars (his goal is to make
one for each of his four now-preschool grandchildren), with his
specialty being in body work.  He found a product he loves which, as I
understand, is much safer to use than most rust removers because its
water based, but is still very effective.  The product is called
"Safest Rust Remover" and he bought it from a sales rep in Ohio whose
email is rustgonesafely@yahoo.com.  Good luck!

happytobeme

Jackson,

I tested something for you before posting my suggestion. Don't laugh
just yet. It worked.

Tomato sauce. (Ketchup for you Yanks!)

I soaked some old (forged iron) farm tools in the sauce for about 24
hours. The parts submerged came back to clean bare metal after being
washed down.

Your question asked for "best". I presume you mean most efficient
without regard to cost. Well, tomato sauce is slow but it's on the
cheap end of the scale of chemicals. Winsplit suggested Kero, equally
cheap. An old timer friend also suggested Kero for old farm machinery.
As in horse-drawn stuff. (No carburettors to worry about). After
soaking in Kero, light a fire under the implement for the final clean
up.

What type of machinery do you have? Are there electrical or mechanical
bits exposed that can't be sprayed with liquid?

Phil

Take a look at this product:

CHASSIS SAVER? Rust Preventive Truck & Auto Underbody Coating

http://www.magnetpaints.com/underbody.asp