does anyone have a simple / plain English explanation of how chemical gun blues work.
i have some, Birchwood Casey super blue liquid gun blue here, the active ingredient would appear to be selenium dioxide. part of the operation involves saturate the metal in gun oil and letting it cure overnight. does the colour of this oil effect the final result?
is this a coating or is it somehow altering the chemical structure of the steel?
i haven't a clue really, but i would assume it's a coating?
many thanks for your time in advance.
"if you want to know the value of money, try borrowing it" :) ???
Most cold blues use selenium and are, at best, only marginally effective. The addition of the oil at the end of the process is to prevent after-rusting, and does tend to lighten the colour. The secret is to have the parts perfectly clean of oil and finger marks, warm them slightly and apply the blue. When completely dry, burnish off all residue with plain steel wool without contaminating the surface with your fingers, and apply some more blue. Three or even more applications may be required to achieve a satisfactory result. The final finish does not wear very well and should not be handled more than neccessary. After nearly 40 years as a professional gunsmith I have never found any cold blue that was very good (compared to proper blueing) and I have tried them all.
I've used Chemical Black for quite a few restorations and found it quite good. Preperation as always is the key, I never handled the parts between the diferent treatments, and the coulor is very even. I've not tried anything as large as a Bren yet, mainly due to the fact I've never had a tank big enough to do it (until now), but I intend to have a go when I can get the bead blaster at work running.
I've restored quite a few Brens using sandblasting followed by submersion in a cold chemical bluing. I've had the Birchwood Casey by the gallon, and found it to be quite poor overall. In fact, I still have a gallon laying around somewhere which I have no intention of ever using. I've started using Brownells OXpho Blue, which is hands down the best cold bluing agent available. It is more durable than any other cold bluing, but still not to the standard of parkerizing or hot bluing. Even over welded areas, it gives a consistant finish, which is almost discernable from the origional Bren finish.
Brownells won't ship the stuff out of the US (although I manage to bring it up 5 gallons at a time into Canada).
Chemical gun bluing is just a coating based on an oxide of the coating agent. It merely bonds with the surface of the metal, which is why the metal must be really clean beforehand. Parkerising or similar phosphate finishes on the other hand work by using acid to etch into the steel surface to form a much stronger and more durable bond.
BTW Kev I've managed to obtain some Oxpho Blue from Brownells, not difficult if you have pals in the US, with your contacts you shouldn't have any trouble getting the stuff. ;D
Its available in liquid or creme. I can't wait to use it myself.
BTW I've not had any problems using Birchwood Casey Super Blue on small parts, the secret is to use a soft cloth mop on a hobby drill to polish the blued part to bring up a shine. The action of the mop seems to harden the blue off leaving a light 'charcoal furnace' blue that matches Colt blues very well and is surprisingly durable.
'V' have you used the Oxpho Blue yet ? ......is it that much better than the Birchwood Casey cold blue ?
A few people who I have contacted a guy who has restored a couple of Brens in the US, and they have recommended this stuff. Apparently there is no to very little effort in using it! you would have to be a complete cave troll to mess it up (Someone else's words not mine). I don't have any contacts in the US, Well I do but they are currently on Active duty in Iraq! I would also be interested in some, if I could get it?
Last Edit: Feb 13, 2007 1:46:18 GMT 1 by piperalpha
Anyone found a good cost effective product yet! Clark has recommended TOOL BLACK. But I have been quoted £150 for a kit. If there is interest I may buy it, do my Bren and then post up the results! And if anyone wants it doing I'll do some small parts at first at a reasonable cost...
Heres some work I did with Oxpho Blu. All or at least most of the pics were taken without a flash to get the proper colour. It comes out a very dark colour as you can see and is very simple to use. The one thing I found with most cheap bluing product is it has a life of only a few months. Most of the cheap bluing like the Birchwood casey stuff bled off.
What I found with Oxpho is it went on deep and dark and stayed on the gun. There was barely any bleeding and it only took about 2 applications. There was no variances in colour like most cold blue kits and it did not streak.
I heated up the metal a bit before application and its still going strong no issues at all. Strong stuff.
Anyhow I did my BAR with it
As well as my 1919A4
I was told the MK2 S here was done with OXPHO as well.
many thanks for your various replies submitted over the last few months. i feel much better informed now.
i like the sound of the Brownells OXPHO-BLUE product, but contrary to popular belief the cost to ship to the UK is a little out of my range! :( (see a recent communication from the big B below)
anyone in the UK manage smuggle some in and willing to sell me some?
----- Original Message ----- From: "Sandy Moranville" <firstname.lastname@example.org> To: <erikthecat@> Sent: Tuesday, March 13, 2007 3:05 PM Subject: RE: Website Support Contact
Good morning...the only method of shipment for oxpho blue would be by ocean carrier. Their fees range from $850 to $1000.00, reason being that proper procedures must be taken in case of spillage or leakage.
Thank you, Sandy Moranville
-----Original Message----- From: Sent: Tuesday, March 13, 2007 7:12 AM To: Sandy Moranville Subject: Website Support Contact Message:
hi, a few questions if i may? is there a UK distributer for this product yet? have shipping restrictions changed on this product? I am told UPS now ships dangerous goods overseas , do you know if that is TRUE? what would typical shipping to the UK be? many thanks for your time. regards, GaRy:) in the UK, i'm just a regular hobbyist.