Cleaning up a rusty M82 scope and mount

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12-28-2020, 09:54 PM
Harlock

2 Attachment(s)

Cleaning up a rusty M82 scope and mount

I got a group of scopes on auction recently, and while 2 of the 4 are in decent shape, I could use some help and advice on the other two.

The main one is the attached M82 scope with a mount for a M1C Garand. The crosshairs look fine, but the scope and mount are covered in rust. I was considering just using some nylon brushes with oil and a lot of elbow grease, but not sure if thats the best bet. Hoping to get feedback here about how others with more knowledge than me would approach this project...

Side note, if you have a M1C Garand serial # 3,447,468 you should contact me....

The 2nd damaged scope is a M73B1 with broken crosshairs - anyone have any recommendations for companies that could do a good job replacing those?
12-28-2020, 11:03 PM
ssgross

surface rust is removed by a good penetrating oil and fine steel wool. I have found Kroil or Birchwood Casey Barricade work very well. That said, it is a general rule never to use such types of oils on any scope as it would work its way inside. In fact, all the reproduction scopes from Hi-Lux, including their M82 repro, warn against this specific thing.
Just go very slow, don't slop it on, and work on a small area at a time, wiping away the oil frequently so it doesn't accumulate.
As for repair, check out https://www.vintagegunscopes.com. I have not done business with them personally, but they frequent my search results when looking for all things old scope related.
12-28-2020, 11:34 PM
butlersrangers

First, protect the lenses, a cleaning patch and swatch of tape could work.

A pad of #0000 steel wool, soaked with Hoppe's No.9 solvent, will remove light surface rust and not harm patina. Go slow following any 'grain' in the metal finish.
Use paper toweling to occasionally remove the 'rust slurry' and monitor progress.

Hard rust scale can be moistened with solvent or oil and broken-up & lifted with the edge of a real "copper" penny and bit of pressure. (Kind of a shaving or 'wood-plane' action).

A slurry of linseed oil and rottenstone can be worked with the edge and flat of a popsicle-stick, once again, respecting original metal polish lines and wiping rusty liquid off, to check progress.

The goal is to remove rust, leaving blue and smooth 'brownish' patina.

Good Luck and keep us posted on your progress!
12-29-2020, 08:20 PM
Harlock

Thanks for the input! I'll hopefully try rubbing some of the smaller rust spots down with some hoppes tomorrow, and thats a good heads up about the glass. I actually was trying to remove the scope from the mount today and discovered 2 of the 4 screws are badly stripped.

I was talking with the folks at columbus machine works who repaired an op rod for one of my garands and they said they could probably handle restoring the worst of it without too much handling. I'm going to send them more pictures since I don't want to get a screw stuck in the mount...
12-30-2020, 03:45 PM
Harlock

3 Attachment(s)

Updates: I started with the two easiest of the scopes. An M84 that had 1 bad patch of rust (should be obvious which is the starting state) and the M73B1 that doesn't have broken crosshairs. The 73 just needed some gentle scrubbing, especially around the serial plate. The 84 took more intense active scrapping, but I think it looks pretty good now (closeup is of the same rusted spot). Tomorrow I'll start the fun ones...

I also realized why 2 of the screws are so damaged on the 82 mount. Looking closely, they are staked while the other two were not. Who know why. Previous owner went to town on them, and I think I'll just leave it mounted to clean around it. Under the bracket I got off, there really wasnt any additional rust.
12-30-2020, 04:13 PM
Salt Flat

Harlock, That looks pretty good. I think you went to the right level of cleaning without going crazy on it. Salt Flat
12-30-2020, 04:21 PM
ssgross

looks a lot better. I've had several older weaver rimfire scopes that got this treatment - much heavier rust than yours. I like to cold blue the corroded areas and pitted areas where the finish is removed. Not only helps to preserve from future rust, but makes it look less neglected while keeping its beauty marks. The cream type works best for this since it won't run everywhere. I think BC perma-blue is too bluish to match - Brownells oxpho matches up great. After final cleanup, I rub with RIG - leave it on for a few minutes and buff away the excess. It melts as you rub. Renaissance wax is another great choice if they won't be handled often.
12-30-2020, 08:14 PM
rcathey

I think I was bidding on this lot too.
Looks like the scopes found a good home though!

Nice work so far.
12-30-2020, 10:51 PM
Harlock

Quote:

Originally Posted by rcathey

I think I was bidding on this lot too.
Looks like the scopes found a good home though!

Nice work so far.

Ha, so far I've run into folks on the cmp board as well who were bidding on it. I think I just got lucky in the live bidding as it seemed like most people put in absentee bids.
01-01-2021, 02:30 AM
Surpmil

I have cleaned objects like this with fine stainless steel brushes in a Dremel tool. Of course you need to be careful: test on an inconspicuous area first, go slowly, and use a good magnifier and plenty of light so you can see what you are doing. A soak in a penetrating oil is good to soften rust scale first. Care must be taken not to brush over any sharp edges are they can be worn "white" very quickly. Used carefully I've never had a problem. The brushes are available cheaply on eBay. The biggest danger is to the eyes!

Steel wool is effective, but the fragments tend to get into every nook and cranny, not to mention carpets, socks and the soles of one's feet. Of course wires from wire brushes are even worse, and the offshore brushes tend to shed wires quite a bit at 5000rpm or so!

Probably best done inside a small blast cabinet or a cardboard box with a piece of glass or perspex sitting over the open top, a hole cut in each side for the hands, and maybe one for a light. I guess a plexiglass box would be ideal and if one really wanted to get clever, a couple of heavy rubber glove cuffs over the hand openings for a bit of a seal? Which reminds me that I've got such a box sitting around here...
01-01-2021, 07:59 PM
browningautorifle

Quote:

Originally Posted by Surpmil

I have cleaned objects like this with fine stainless steel brushes in a Dremel tool.

I've used some of those on occasion too and have been blown away that all the rust was gone and no damage or removal of anything else...the brushes didn't last long but they worked great.

I just do the work out in the shop where small detritus doesn't matter.
01-09-2021, 02:22 AM
ssgross

Quote:

Originally Posted by browningautorifle

the brushes didn't last long but they worked great.

my experience as well. I resorted to this on that Enfield named Doug - think it was my first milsurps post, and first serious milsurp cleanup ever. The spot where the barrel contacted the forend had thousands of deep tiny pits I couldn't get the rust out of...so I started with dremmel and fine brass wheel, no go. switched to the stainless one and out it came, with whatever was left of the finish underneath still intact on the ridges between the pits.

Quote:

Originally Posted by browningautorifle

I just do the work out in the shop where small detritus doesn't matter.

I made the mistake of not putting my leather apron on over my sweatshirt...for the rest of the day I would randomly feel little pricks or sharp tingling all over my chest and stomach...thought I was becoming ill, rash or something. After several dumbfounded minutes a magnifying glass showed hundreds of tiny wires poking into my clothes.
01-10-2021, 10:03 AM
Harlock

Yeah, depending on what happens I may try a brass dremel brush first and then stainless steel for the M82. Waiting to hear back from a machine shop about them getting the staked screws out to start, as just due to the rarity of the scope I don't particularly want to to try it myself....

Speaking of "metal wires everywhere" I used to use cheap brass wool for cleaning light surface rust. I regretted it when that stuff fragmented everywhere, and I was feeling it in my socks for weeks. I recently discovered brass velcro brushes at a tack shop, and they have been lifesavers: Velcro Brush - PBS Animal Health (just as an example) super cheap, and they don't flake everywhere.

Other updates - I sold the M73B1 with the broken crosshairs to another collector who wants to try and do a full restoration (sourcing a correct tube alongside fixing the crosshairs themselves). The other M73B1 and M84 are completely cleaned as I posted pics before. I'm considering swapping the M84 onto my 1903A4 as its easier to remove and store without the scope that way. Right now I have a Lyman Alaskan B series on it. Maybe one day I'll track down a Lyman M73 or M81 marked scope to fill those holes in my collection...