Armi San Paolo Red/Plum/Purple? Finish

[Seiyoujin]

I was hoping to see if anyone knew why, and how the frames on some older Armi San Paolo guns were finished so that they turned out a reddish, almost plum-maroon color. The reason? My New Model Army replica has a burr that never got removed, and needs a little cleaning up to give both the loading lever, and cylinder pin better clearance. Unfortunately, I do like the original finish, so I was hoping that somebody might know how to replicate it once metal has been removed. I do know that Birchwood Casey has their plum brown finishing solution, but that ends up much more brown, and less red-purple. Thanks!

 

[Captain*kirk]

I have been told the frames turn the purple hue after the copper in the metal begins to leach out into the bluing on the older guns with time. I have several that have done the same thing. Some early guns apparently had a higher copper content in the metallurgy. I don't know of anyone that has a touch up bluing to match it, though.

 

[hawg]

That's not the original color. Cap may be right. I've also heard it happens only with cast frames. I've got a Pietta .36 Remington made in 76 that has turned purple and I've had Rugers do the same thing. The only thing they have in common is a cast frame.

 

[Seiyoujin]

That's not the original color. Cap may be right. I've also heard it happens only with cast frames. I've got a Pietta .36 Remington made in 76 that has turned purple and I've had Rugers do the same thing. The only thing they have in common is a cast frame.

So regular bluing would probably end up the same color at some point? If that's the case, maybe there's a way to speed up the aging process. The interesting thing is that my EuroArms, and pre-EuroArms A.S.P. N.M.A.s both have completely different coloration on the frame (But no other parts), despite only being a few years apart, and most parts being close to identical, and swapping between the 2 without issue. Both frames actually do have the same burr that needs removal, but it's slightly less pronounced on the later one.

 

[Eyrie G. Dogg]

I have two Pietta Remigtons (.36 and .44) made in 2011 [CH], bought simultaneously from Cabelas, that have really plumed-up. It took a couple of years of use on each for the frames to begin to show purple. That came as a pleasant surprise. Another Pietta Rem from 2000 that I use is only getting gun-metal grey. That's a good color too.

Gun finishes sure do have individual personalities.

 

[hawg]

So regular bluing would probably end up the same color at some point?

I wouldn't count on it. I've had plenty of Piettas and a few Rugers that didn't turn.

 

[bannockburn]

Seiyoujin

Many years ago I asked that same question of H&K of a P7 that the metal was turning to a plum color. They wrote me back that it could be: 1) a change in the metallurgy that they were using at the time, 2) it could have something to do with a variation in the heat treatment, and 3) it could also be affected by a slight difference in the bluing solution. It could be any one of those conditions or else a combination of sorts of two of them, or all three!

 

[Navy Six 2]

I have a couple of Euroarms Rogers & Spencers that have a similar color on the frames only. Several years ago I had to re-blue a early third gen Colt SAA backstrap and trigger guard. It was originally the standard blue but three different attempts at a re-finish( a local guy, then the Colt factory then Turnbull) and each time it came back a plum/purple color. I couldn't understand how Colt could get it right originally but not a few years later. I finally had another local guy rust blue it. A slightly different color( kind of a smokey gray) but it looks good and at least its not purple.

 

[Ephraim Kibbey]

This from a discussion on the Ruger Forum:
https://www.rugerforum.com/threads/... parts are left in,aging, gun parts turn plum.

 

[J-Bar]

Remove the offending burr. First things first. Play with the finish afterwards. Quick blue + BC Plum Brown+Blackpowder ash in water+ focused brief flame+polishing with Flitz/oily oooo steel wool. Sometimes you get a nice surprise. But the burr must go.

 

[noelf2]

I have a Uberti 1858 carbine bought new from Cabela's in 2011 (CH date code). The frame turned an awesome plum color after a couple years, so not just happening to Armi San Paulo, Pietta, etc.

 

[Driftwood Johnson]

Howdy

Bill Ruger talked about this in R. L. Wilson's book, Ruger And His Guns. Ruger has always used Investment Castings for many of their parts. Early on, they noticed a lot of their parts were turning a purplish hue after bluing. After extensive research, Ruger concluded that the amount of silicon added to their steel alloy was causing the 'purpling'. The silicon was added to the alloy to help promote it filling the molds. Ruger reduced the amount of silicon in their alloy, and the problem went away.

Here is a photo of an old Three Screw Flat Top 44 Magnum Blackhawk that shipped in 1958. Notice the color of the loading gate.






I suspect any other cast frames with a little bit too much silicon in the alloy would exhibit the same problem.

 

[hawg]

I had this Single Six made in 1982.

 

[Gaucho Gringo]

I have a couple of Euroarms Rogers & Spencers that have a similar color on the frames only. Several years ago I had to re-blue a early third gen Colt SAA backstrap and trigger guard. It was originally the standard blue but three different attempts at a re-finish( a local guy, then the Colt factory then Turnbull) and each time it came back a plum/purple color. I couldn't understand how Colt could get it right originally but not a few years later. I finally had another local guy rust blue it. A slightly different color( kind of a smokey gray) but it looks good and at least its not purple.

My Euroarms Rogers & Spencer revolver from the 70's has turned plum color also. My Euroarms 1851 and .36 1858 NMA have not. At least I know I am not alone.

 

[Jackrabbit1957]

I kinda thought it may have something to do with carbon content, I did see some interesting colors on a P17 Enfield I hot blued a hundred years ago, it came out a peculiar gold color, it went back in for another 30 minutes, came out purple, back in for another 30 minutes and all was good.

 

[Reinz]

Some of my Bren Tens turned purple as well as an HK P7m8 before I refinished it.