Stainless Steel Barrel Polishing?????

MI.264 said:

Hey, what kind of system do you have to achieve this. Is it something not To expensive to set up?

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just a cheap cabinet set up

Green scotchbrite does a good matte finish. Just wrap the barrel and give it a couple twists, wrapping your way up the barrel making sure to overlap the last one.

Easy to fix if you scratch it too.

If you really don't want it to rust you'll need to send it out for passivation. I've never heard of this being done with any firearm, but it's an important step.

Every cutting tool used in making the barrel (or anything else SS) imparted some ferrous content into the stainless. Passivation is a nitric acid bath that removes the ferrous impurities without harming the SS. When I was working for Burton Sub-Sea Electrical Connectors we passivated all of our SS parts per QQ-P-35C so that they wouldn't rust when exposed to sea water.

ntsqd said:

If you really don't want it to rust you'll need to send it out for passivation. I've never heard of this being done with any firearm, but it's an important step.

Every cutting tool used in making the barrel (or anything else SS) imparted some ferrous content into the stainless. Passivation is a nitric acid bath that removes the ferrous impurities without harming the SS. When I was working for Burton Sub-Sea Electrical Connectors we passivated all of our SS parts per QQ-P-35C so that they wouldn't rust when exposed to sea water.

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You just sent me down a deep rabbit hole. Pretty interesting, used a lot in the medical field. I'm curious as why it hasn't made it to the gun industry. I would guess that it's cost inhibitive to passivate (is that the correct term?) barrels when we don't see a ton of rust on stainless barrels even when fluted.

I've never polished a barrel, but I did take a surplus CZ-75b and refurbish it as a surprise present for my dad. I hand polished the entire thing and when we took it to a gun shop to have blued my dad was moaning that he liked the look of it polished. The smith told us that with a high gloss polish it won't rust, I then turned and gave the pistol to my dad as the bluing was the last step of the refurbish. To the smiths credit it's never rusted at all and it's been 6 years since I did the work.

ElCidAviator said:

You just sent me down a deep rabbit hole. Pretty interesting, used a lot in the medical field. I'm curious as why it hasn't made it to the gun industry. I would guess that it's cost inhibitive to passivate (is that the correct term?) barrels when we don't see a ton of rust on stainless barrels even when fluted.

I've never polished a barrel, but I did take a surplus CZ-75b and refurbish it as a surprise present for my dad. I hand polished the entire thing and when we took it to a gun shop to have blued my dad was moaning that he liked the look of it polished. The smith told us that with a high gloss polish it won't rust, I then turned and gave the pistol to my dad as the bluing was the last step of the refurbish. To the smiths credit it's never rusted at all and it's been 6 years since I did the work.

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There are different grades of stainless. And as long as it has a light coat of oil or such it will be fine. Now if you were to leave polished metal to the elements. You can be sure of the outcome. I have polished different materials on motorcycles exposed to weather. Metal will rust fast. Aluminum will oxidize fast also without a polish that last. I welded manure spreaders that were made with high grade stainless. They never rust. But everything else does.

Generally the 300 series of SS doesn't rust in normal environments. Those are a dang poor choice to use in making firearms or knives. Recall how very early SS firearms had major galling problems? Right, likely they chose 300 series to make them from. As a class they are terrible for galling when moving against each other. Most SS fasteners are made from an alloy known as "18-8", which is in the 300 series of SS alloys. No wonder those screws when used with SS nuts seize so easily. The nuts are made of the same alloy! Generally a hardware store SS bolt is no stronger than an SAE Grade 2 bolt of the same size.

Commonly SS barrels these days are made from a 400 series SS. I don't know too much about this family, but I have seen it rust. Whether that was from carbon steel inclusions, or was the base metal I don't know. Normal environments don't seem to be a problem, but extreme environments or get some blood on it and it will rust.

The thing to understand about SS steels and aluminum is that they both will form a self-protecting coating of an oxide on their surfaces. It is really, really thin and left undisturbed is usually enough to stop any further corrosion. Not always, but usually. The oxide is a barrier to more oxygen reaching the base metal. This is what all coatings are trying to do, form a barrier that oxygen can not penetrate. Some coatings, like bluing, form a porous surface that aids in retaining oil on the surface. It is the oil that is the oxygen barrier, not the bluing. Anodizing is similar, the first step in the anodizing process is a porous surface. This is then filled with an oxygen excluding substance that is tinted in the various colors that we're used to seeing.

ElCidAviator said:

You just sent me down a deep rabbit hole. Pretty interesting, used a lot in the medical field. I'm curious as why it hasn't made it to the gun industry. I would guess that it's cost inhibitive to passivate (is that the correct term?) barrels when we don't see a ton of rust on stainless barrels even when fluted.

I've never polished a barrel, but I did take a surplus CZ-75b and refurbish it as a surprise present for my dad. I hand polished the entire thing and when we took it to a gun shop to have blued my dad was moaning that he liked the look of it polished. The smith told us that with a high gloss polish it won't rust, I then turned and gave the pistol to my dad as the bluing was the last step of the refurbish. To the smiths credit it's never rusted at all and it's been 6 years since I did the work.

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I can agree with Dad on this one. Bluing would have done it no justice. Beautiful piece there. I do favor the CZ 75 myself

MI.264 said:

Thanks everyone, going with the bead blasting method to create the Satin finish look.
Appreciate the help.

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This was a high polish gun that was pretty scratched up and looked poor.

I blasted in with #10 glass bead at 100psi, this media can be found easily online

M.

vmaxmike said:

This was a high polish gun that was pretty scratched up and looked poor.

I blasted in with #10 glass bead at 100psi, this media can be found easily online

M.View attachment 443527

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How easy is it to mar your finish ? I have recently purchased a few stainless models. And am looking for a finish just like you have. That is a sweet looking piece. Can I ask what kit you used to glass bead ? I gonna guess you used a glass beading cabinet ?

It's as durable as any matte finish is. The beauty of it is if/when it shows wear just blast it again.


M.

I used to work at a shop that built food handling equipment. We hated carbon steel. Every time any carbon steel was brought into the building every inch of the shop had to be passivated. In the food industry you can't take a chance of something rusting.

There is a lot of different grades of scotch brite pads. We used them to polish out welds.

budlight said:

I have a few SS fluted barrels. I spent hours using a white soft buffer wheel on my grinder with SS polishing powder. I polished before I installed the barrels. I also had lots of time. You could be done in an hour or take lots of time and give the barrel a mirror like finish.

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I made the pink one for my daughter and the picture doesn't show how beautiful these barrels are.