Polishing a GP100 and Frustration

[[email protected]]

I have for the last week been in the process of polishing my GP100. The gun was pretty beat up and I figure didn't have a lot to lose. I have read other post about the process needed and it's going pretty good, but what is frustrating is that I have a nice polished finish but still can see the original machining marks, you can't feel then, if you run your finger nail over the areas it is smooth as a baby's butt, I know by some standards it's probably good enough but I can still see the marks and that is frustrating to me. Can anyone give me a suggestion on how remove the machining marks, I know if I use a 1000 grit wet and dry sandpaper it will start to remove the roll marks, which I don't wnat to do.
What I have used to this point to remove marks is; scotch brite pads, table buffing machine, dremel tools, Mothers Mag Polish.
Please help.
Thanks

Cigarbum

 

[WOB]

I suggest you leave it alone. What you are asking for is the kind of finish that master metal polishers produce when they work on newly made guns at factories like Colt and S&W. They have many different types of polishing tools and many years of experience that allow them to produce a mirror finish without changing the shapes and contours of the gun. Flats remain flat, sharp edges remain sharp, hole aren't saucered, lettering is not pulled, etc.

With your tool list and lack of knowledge, you have no chance. In the old days it was often said that it takes 10 years of experience to make a master polisher from an apprentice. Better that you be happy with the superficial polish that you have done. If you want perfection, send it to Hamilton Bowen or one of the other custom pistol smiths. They can do what you want but it will be expensive.

 

[pokute]

To even begin, you need to do some real research, learn how to handle files and stones, and then practice. Before carving up your GP100 further, I recommend getting an old junker revolver from your local dealer, and learning to handle the files and stones on that. Careful, slow going can make a neat job of it even for an inexperienced worker. You have to start somewhere. A steel flat and some parallels can go a long way as holding fixtures to take some of the uncertainty out of the work. Don't try to file without using chalk (or soapstone, available as welder's chalk) on your files. Work slowly, files can take a lot of metal off very quickly. Polishing is the FINAL step, and very little metal should be removed when you get to that point.

You will mess SOMETHING up before you succeed. In my case I was lucky to only have bunged up a 1911 barrel hood. A friend who does micro-welding welded it back up, and on my second try (working much more gently with the file, and with some simple fixturing made from oak) I got very good results.

 

[[email protected]]

I can't argue with knowledge and experience. I will quit while I am ahead. The gun was a beater to begin with so I had nothing to lose. I will go ahead and give it a final polish and clean it up. I will post some pictures once I get it cleaned so you can see where I ended up.
Thanks to all.

Cigarbum

 

[rugerguy]

It all depends on just where the marks are, and to what degree (how bad) they may be..I'm guessing you are talking about a stainless steel version?? relatively soft and easy to work with,stay away from power tools and only use small ,,fine , like 'Swiss' files to remove any 'marks', and of course stay away from any and all roll marks, serial numbers etc......... once the marks are out, you can blend in with fine emery paper, then Scotch brite pads to ;'replicate' the factory or original finish......once it is ALL evenly blended, NO marks ( tool marks, pitting, nicks or scratches) THEN if you ewant , you can "polish" it out, make it SHINY...if the marks are NOT "gone" all you will do is make it ALL shiny, with marks remaining in the finish..........as noted above, it takes "practice" and a keen eye, yes "neatness counts".I've been doing it since the 1960's and have seen about any and all 'boogers, goobers, FUBARS" and can get most out, even those that fell out of a truck, dragged on concrete, been in fires, and left in rivers and lakes.......... 8)

did I say "stay away from power equipment..."? :roll:


and YES "draw filing" is an art.... :wink:

 

[roylt]

First off welcome. Second, if you think it is a junker GP go for it. It is yours so why not. Do post pics when done.

 

[Flash]

I've polished many stainless guns and used up to 2000 grit with beautiful results. I don't go under 400 grit since the cut would be too deep and make marks of it's own. I use gray, red and green rouge on a bench buffing wheel in that order and the finished product looks like stainless flatware when I'm done. There isn't any special technique to polishing metal other than not causing more scratches with the grit you're using. I use kerosene as a lubricant on the silicon carbide paper so it doesn't load up and cause more irregularities in the finish. The grits I mainly use are 400, 600, 1000, 1500 and 2000 in addition to the rouges.
Shop here www.supergrit.com

 

[TINCANBANDIT]

keep going at it, it will get better, use Mother's or Flitz (Mother's is cheaper) and polish the gun while you watch TV in the evenings

Here is what I did to my Security Six, S&W Model 65 and S&W model 629 Classic

http://tincanbandit.blogspot.com/2013/10/polishing-your-gun.html

 

[The Blackhawk Kid]

I would keep polishing with Flitz. When I start polishing I use files and stones to get the rough machine marks out. Then I go to the Tampico wheel to blend the surface to a even blended finish. Then I go up on the polishing wheels, 400 grit, 600 grit etc. Whenever it suits you stop! You can't screw up a GP-100. (unless you round off surfaces on the cylinder.) Keep on shooting! BHK

 

[Precision32]

Polishing alone will not remove the machine marks. Use 600 grit wet/dry sand paper as a start and work your way down the line. Each change of grit will make smaller and smaller scratches until the polishing step will leave it without the tooling marks.

 

[Jimbo357mag]

I found this article online that may help folks.

http://www.teslamap.com/public/polish/index.html

 

[pokute]

The article that Jimbo357mag references mentions the possibility of a passivated finish. I discovered that my new SS SBH has some kind of slightly warm-colored finish when I made some mods to the grip frame and then brushed it and put the gun back together. The grip frame now has a relatively neutral cast compared to the warmer frame and barrel.

 

[SteelShooter]

Don't think Ruger uses a passivisation process on their stainless guns or parts.

Basically it is dipping the parts in an acid solution to remove "contamination" during the machining process.

 

[woodsy]

Don't think Ruger uses a passivisation process on their stainless guns or parts.

Basically it is dipping the parts in an acid solution to remove "contamination" during the machining process.

Yes, there are acid solutions, but the first ones (sulfuric and hydrochloric) are to remove surface contaminants. The last bath (20% nitric acid) is to form a "passive" surface on the stainless. It's an easy process if the industrial plant has set up the "passivation line". Subsequent re-contamination (with enough force to erode the passive layer) of an iron-bearing material requires re-passivation. This was part of my career/life for more than ten years, in the surgical industry.