Cold Blueing Steel

[chunkolini]

Over the years I have sold quite a few sets of shelves with the frames treated with gun blue.

Very effective, a bit of a pain to do but as an extra it is worth doing.
So far I have been using Casey Gun Blue, bought in tiny bottles, ok it goes a long way but is there a cheaper/better industrial product?
I dont want to buy gallons of it as I rarely use it but curious as to what else is available.
Edit, it needs to be a cold process as heating these up would be a nightmare.

 

[MattF]

Edit, it needs to be a cold process as heating these up would be a nightmare.

If I recall correctly, traditional bluing methods don't require heating the items up as such, merely dunking the items in boiling water once the acid is applied, to neutralise the acid and create the blue effect.

 

[Perry Owens]

Cold gun blue is sold in small quantities because it is really intended for touching up scratches or bluing small parts such a screws. Although some manufacturers say it is possible, cold bluing large areas like gun barrels is rarely satisfactory. The biggest container of cold blue I have seen is Oxypho Blue, which comes in 4oz bottles. Professional gunsmiths use hot bluing solutions but these require temperature controlled immersion tanks and heated humidity cabinets.

 

[chunkolini]

It would be difficult to dunk these into boiling water, they are usually 2m long.
The stuff I have been using Casey Gun Blue has Selenium Dioxide in it whtever that is and colours the metal chemically, no mention of 'acids' on the packaging, smells well dodgy but wearing gloves and in a well ventilated space have had no problems yet.