I have a 57mm case that seems like it has been coated in lacquer at some point, and is all sorts of discolored and with tape residue, etc… I don’t think it is anything too rare, and the projectile is likely a stuffer, so has anyone ever sandblasted or otherwise cleaned anything like this to bring it back to looking new? I realize we normally avoid this, but this piece will be for decorative display, not so much for collecting, and I don’t mind it looking new again. Anything would be an improvement over its current state.
Matt, you may try a simple paint remover (solvent based) and see what is below that current coating.
Sand blasting usually destroys/removes the original metal surface and before knowing what you have there (might be in perfect condition below) it might be worth to find out,
Sand blasting is only recommended with items which have a heavily corroded surface.
Ok, so sandblasting could destroy the smoothness of the surface and leave it gritty or blemished I take it? I will try some various solvents which I have at work and see what happens.
This is the case in question:
Yes, this will be it! As you say the surface will be destroyed/removed.
Sand blasting brass cases is not recommendable at all.
Just in case you were not aware, that’s a Canadian manufactured case - CL/C - Canadian Motor Lamp Co, Windsor, Canada. They also manufactured 25 Pr cases - all of which were recalled. The story goes that an Inspector didn’t understand his role and passed every case presented to him, needless to say a lot of the cases were far from perfect.
If your paint stripper or solvents don’t work you could try a less aggressive blasting media such as Walnut shell or Peach pip. If you do, then test them on a small area first. I have used these on Aircraft components over the years with very good results. Reduced pressure on the airline (supply) will limit the “wear” factor on the component but I say again “test a small area first”
Just thought I better add; you buy them already crushed and graded to a mesh size to suit, its not the whole shell :)
I can add some pictures of a brass 12 bore case that has been blasted if you want?
No sand blasting or bead blasting. Paint remover and then clean it with ISSO case cleaner https://iosso.com/products/case-cleaner-case-cleaner-kit/ followed by a good rub with some extra fine bronze wool. http://www.ebay.com/itm/Bronze-Wool-3-Pad-Pack-Fine-/380316364516?hash=item588c9f2ee4
Matt- Looks like the projectile is more or less correct for that case. As an Armor Piercing shot, the normal color would be black.
With brass case like that it is most likely a prior owner who polished it once and then added a coat of lacquer or varnish. That should strip off pretty easily with some sort of paint remover or solvent stuff, so no real need to sand/bead/walnut blast.
If you were talking about one of the steel 57mm recoilless rifle cases with all the holes, that would be different. Those, and many other U.S. cases were steel, and given some sort of paint type finish, usually a sort of translucent honey to dark brown color. If those start to get rusty underneath they get ugly in a hurry and it would be perfectly okay (in my opinion) to sand blast and repaint in the original colors.
Type A before blasting, circa 90 year old case in fair condition.
Type A Head Stamp before blasting.
and a Type B case, slightly newer case with a different disfigurement.
These are the results of a very light blasting with Walnut Shell (from memory at 40 to 50psi) with the gun held about 6" from the object. This is what I would describe as a very light blasting and the gun was not held for any length of time at a single point. More severe results are achieved with higher pressures, longer times, etc. etc. This media would have been pre-used and not brand new as I would have used the blasting cabinet after a run of components. The example was done about 10 years ago.
Type A side view after blasting.
Type A head stamp after blasting,
the same result was achieved on the type B case.
Somewhere I have some examples of harder media but cant find them at the moment so I have not added any comments.
Let me add that I would NOT do this to any cartridges (shotshells) in my collection unless it was 100% necessary. These were done purely as tests as I had 100’s of that type of case and it gave me an indication of what could be achieved,
I bathe them in lemons brause tablets 1-2h and then polish with steel wool
The condition of the lacquer was so bad, and no solvent would touch it (we have some nasty stuff at the RV dealership), that I have resorted to scrubbing it with a polishing compound called Colonel Brassy, and also using 1000 grit and 2000 grit finishing wet sandpaper. It is working really well so far, I am about 6 rounds of scrubbing / sanding into it and have 80 - 90 % of it clean.
Will have to try that, thanks for the info! Tom from MN
It’s too late now, but for future reference, usually gel type paint stripper will remove lacquer.
True on the gel-type paint strippers, I have used 5F5 before with good results on other painted metal. This shell was so nasty though that it probably benefited from the abrasive scrubbing. I have it 100% clean and I just need to do a final buffing to get the tiny sanding lines gone.
I have had good results using some fine sand in a tumbler type case. I then follow it with tumbling in corn cob or walnut shell media, with a little brass polish added. I would try the chemical paint remover, first. Then, depending on the results, you might be able to eliminate the step with the sand. If you don’t have a case tumbler (or a rock polisher), try to find an acquaintance who is a reloader, as most reloaders have such a tumbler, and would probably let you use theirs. In my opinion, actual sand-blasting would be overkill. Good luck