On Mon, 30 Nov 2015 19:03:55 -0600
-MIKE- wrote:

If you use a phosphoric acid cleaner, like Boeshield Rust Free, there
would be no scrubbing or scraping necessary. Let science to the hard
work.


seems to contradict the instruction from the maker


quote
"Directions. For light rust on steel or cast iron, spray RustFree„¢ on a
rag and wipe surface. Do not spray directly on surface, as it may cause
spotting. For heavy rust, spray directly on rusted surface and scrub
with Scotch-Brite„¢ pad. Wipe off and repeat if necessary. RustFree„¢
works best above 70° F.

CAUTION! RustFree„¢ is acidic and should be used with care.

Test on hidden area before use.
Can cause spotting on cast iron and steel.
Rinse off painted surfaces thoroughly and neutralize with soap and
water. Do not use on guns or black oxide tools.
Can dull paint and plastics.
Not for spot cleaning of table tops.
Do not use on polished cast iron surfaces."