mikeashurst - hot bluing is basically taking the prepared metal and placing it in a tank of heated, bluing solution. Hence the term hot bluing. Cold bluing is more of a do at home, or touch up method of bluing, using a cold or non heated solution. Cold blue can be found at any of the Super Markets for touch up work.
I am not aware of any true professional gunsmiths that would use cold blue as a standard for re-finishing a complete rifle. The standard would be use of hot blue. Hot blue is much more durable than cold blue.
As important as whether hot vs. cold blue is the metal preperation before any solution ever touches the metal. The most cost effective way is to use a bead blasting machien and bead blast the metal. This IMO produces a nice even "matte" finish after the blue is applied. But if you want a polished finish then the metal has to be preparred on assorted buffing wheels with assorted grits of buffing compound. Not as fast and much more labor intensive than bead blasting.
Just looked up some information in my #59 Brownells catalog.
These are national Shop Survey Costs or prices.
General per man hour costs $40-80
Per man and machine hour $50-95
Minimum per gun $35-70
Basic hot blue using wire wheel or bead blast $95-145
Deluxe Hot Bluing (Rifle/shotgun) $135-190
Master Hot Bluing -bright mirror like finish (Rifle Shotgun) $160-250
Regards,
Rob
