FN Browning Auto 5 bluing question

[tpl77]

I have an old standard 12 (circa 1952) that I'm cleaning up and I chose to rust blue the shotgun. It was in bad shape, and so far, I've took it down to bare metal, removed a couple scratches and dings, and worked through a series of polishing exercises. I've completed the receiver and barrel so far and it looks very nice, but not the same as a couple other FN auto 5's I have. As I compare the other FN auto 5's to other shotguns (just plain old hot bluing from Marlin .22's, Ithaca 37's and a Savage .270), the FN finish looks "blue'er" ... a shade closer to blue than to black. Can someone offer to me some background information on FN Browning's original finish?

Thanks

 

[Mortonspoint]

According to my books, FN used a hot solution of potassium nitrate, sodium hydroxide, and water heated to the boiling point.

 

[rcmodel]

Hard to say exactly what hot blue formula Browning used.

But most of the striking appearance is in the polish work done before the bluing. Same with older Colts & S&W's. They had some very highly skilled polishers doing the prep work on them.

Rust blue will never come close to matching it, although it is very very nice in it's own right.

But it will be a more matt-black type finish then the high-polish deep blue Browning used.


rcmodel

 

[tpl77]

I'm hung up on whether to keep the satin type of sheen that comes with a rust blue, or polish it to my best ability and hot salt it. I've rust blued a dozen old guns and feel proficient, but with the hot salts, I would only feel confident if I knew that there was a recipe out there I could follow. If it turned out jet black like all the hot salt bluing examples, I would regret dropping the rust blue process. I think I can get to the mirror like finish with my full effort. It's just the recipe to make a bluish blue that would screw me up... does that make any sense?

 

[rcmodel]

Yep! PErfect sense!

You might want to give Brownells tech service a call and discuss it with them.

Anyway, unless you have an out-building to set up hot-bluing tanks, you are way better off to stay with the rust blue.

The steam & fumes from a hot-bluing setup will rust everything iron or steel in your shop a bright red while you are standing there watching it do it!

It is really nasty stuff to have in your shop or house!


rcmodel

 

[tpl77]

I have built a work center "on wheels" so to speak. I can roll this out the side door of my barn and let the fumes disperse without a worry. I live out in a rural environment, so there's no one around to complain about it. I've all the saftey gear for the work.

I'm going to begin to research a hot salt recipe (or something already made up) that can blue this gun without that typical dark black result that I see so often.

If anyone can point me, I sure would appreciate it. This will be quite a learning experience.

Thanks

 

[rcmodel]

http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=1066&title=OXYNATE~ NO. 7

Every step, every complication, every question the gun bluer can encounter is detailed in this booklet. Ask for a copy today.

Free for asking:

Also, as I said before, the "blue" color is in the surface prep work done beforehand:

http://www.brownells.com/aspx/NS/GunTech/faq.aspx?catid=18&faqid=76

http://www.brownells.com/aspx/NS/GunTech/NewsletterArchive.aspx?p=0&t=1&i=514

http://www.brownells.com/aspx/NS/GunTech/faq.aspx


rcmodel

 

[tpl77]

...that's probably where I'm hung up when I compare all 3 of my auto 5's. The two with the factory finishes are polished to a level the the rust bluing cannot allow. I think I'm wrong for try to compare all 3 side by side.

I caught some information from a similar thread over on shotgun world. I'm learning that rust bluing for a 1950's FN auto 5 is correct for that time. It sounds like mid 60's is when they went to the hot salts. This would then lead me to believe that I should march on with the slow rust bluing on this gun. I'll take that as good news as I like the results so far. I'm comfortable with the process, too.

I landed on my feet!!

Thanks again for the help.