Once in awhile I get feedback on this. I have experienced it myself. Most of my formulas contain copper sulfate. I experimented and discovered there are two major reasons for this. The first is applying too much solution. The second is electrochemical. If you are applying Rustblue in low humidity there is a strong potential [...]
Some of Rust Blue's unique features...

Quality

Research

Precision
Rust Blue American
Modified formula omitting mercury salts as a component. It still produces a fine blue as seen on US Krags plus early Springfields and 1917 Enfield’s. This formula does not require neutralization to prevent after-rusting. Complete working instructions included.
Authentic Products by Rust Blue...
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Rust Blue Frontier Brown
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Rust Blue Damascus
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Rust Blue British
$29.95 Add to cart -
Rust Blue French
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Rust Blue German
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Rust Blue Swedish
$29.95 Add to cart -
Rust Blue Swiss
$29.95 Add to cart -
Rust Blue American
$29.95 Add to cart
What people think of Rust Blue...
I can’t believe that old gun came out so well. I had written it off! Rust Blue was easy to apply and the directions were spot on. Thanks for a great product.

Sweat box/dryer design
January 4, 2017 by Bob Veasey BlogHere is a simple device you can build to dry and steam ripen your rust blueing project. It s a simple cardboard moving wardrobe with a a flap door cut in the bottom. This allows the introduction of a mild steam source or heater. It will greatly reduce rust times and produce superior work. Simply [...]
Barrel steamer built by Paul Sannes
July 19, 2015 by Bob Veasey BlogRustblue on a double rifle
May 31, 2015 by Bob Veasey BlogFollow this link to another customer testimonial: http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/9471048012
Customer Testimonial
March 22, 2015 by Bob Veasey BlogWas very pleased with your product. This was the first run for me. It is the answer for the resurrection of vintage scatter guns. I used your steam pvc method. Did the prime cycle, carded, processed an other coat. I then did 2 ten minute steam cycles with carding at the end of each one. [...]