Gidday,
I do not know any thing about rust blueing and was wondering if there was a web site that explains it.
Thanks,
Peter

Brownells had a reprint of a Bivens article in Rifle magazine which details various metal finishes... It used to be free- get a copy with your next order... Covers rust bluing including formulas for Neidners solution...

Do a search on this site. I've found extensive info on this topic.

Get a bottle of rust blue from Brownells (I used Plinkton to start) detailed instructions enclosed- follow them to the letter. I started rust bluing old tools, pellet guns, and take off barrels-nothing really can prepare you for the results because heat/humidity play a critical factor in the rust formation and thus varies from region to region...

Thanks for the info
Peter