MG81 before

MG-81 Flash Hider Restoration for Nick

I’m officially geeking out right now. Another stellar commission project to work on. And another one that I thought I’d never see in person. It’s surprisingly heavy and solid feeling for how rusty it looks. And of course I’m going to compare my replica to the real thing, take a look at this. Mine is one of the very early Todd’s Costumes, which has some inaccuracy around the scalloping.

Other than the height, the Todd’s Costumes flash hider is pretty accurate. I’ve heard that the DEC flash hider has the same height issue. The diameter of both ends match up perfectly.

Condition and Restoration

There is a lot of build up on the surface, so much so that I’m not sure what the condition of the metal underneath is. It’s not only rust, there is something else there, and it’s hard and doesn’t come off with picking. I’m just going to do what I do with rusty things and put it in the electrolysis bucket over night.

electrolysis 1st round
electrolysis 1st round

Day 2

The electrolysis didn’t do that much overnight. I think that there are several factors as to why, using RODI water and not enough washing soda, very small contact point between the hanger and the flash hider. I mean a little bit happened, just not the dramatic effect that usually happens. After thinking this through a bit, I decided to do another round of electrolysis. The theory I had was that not enough electrical current is able get into the flash hider and travel to through the water. This time I used tap water, a lot more washing soda (enough to make the water cloudy), and I used a piece of copper wire to make a hanger (also I wrapped the copper wire around it for a lot more contact). Pure water isn’t a good conductor, and the RODI was pretty close to pure. It’s all the stuff in the water, salts, minerals, et. al. that make the water more conductive. Copper is a better conductor than the metal fly swatter handle I had fashioned into a hanger, and more pliable so I could wrap it for more contact area. Anyway, I did all of this, more washing soda, tap water, and more and better contact on the negative pole. It worked, and it didn’t take long to see that, even though I couldn’t actually see the flash hider because the water was so cloudy. I could tell by the amount of bubbles coming up and all the stuff that was coming to the surface of the water. After a short period of time the water looked like a vat of chili, orange and foamy with rust. A couple hours it ran before I stopped it to check the progress. The build-up on the surface was just crumbling off. I gave it a quick rub down with my hands to knock as much off as I could.

The surface build up coming off the MG-81
The surface build up coming off

The electrolysis was working pretty well, but there was still a lot of crap still firmly stuck to the surface. I decided to do another round of electrolysis but start over with clean water and washing soda, it was pretty amazing how gross the water had gotten. Round 3 was almost as beneficial as round 2, the water was very orange. I decided that what build-up remained at this time I would have to remove with tools.

Electrolysis 3 MG-81 side view
Electrolysis 3 side view
Electrolysis 3 MG-81 cone
Electrolysis 3 cone
Electrolysis 3 MG-81 back
Electrolysis 3 back

The next step was to hit the surface with light filing in all of the flat non-knurled areas to get any remaining build-up off. I barely had to put any pressure to make the build-up fall off. It really looked like it was cleaned up afterward, but looks can be deceiving.

After filing the flat areas on the MG-81
After filing the flat areas

Since the inside still had a lot of build up and some of the pitted areas likely had some loose surface build up that could be removed easily, decided to wire-wheel the entire surface. It did work pretty well, I was hoping that it would have removed more build up in the knurling and threads on the inside. It really polished up the surface and cleaned a lot of stuff out from the inside of the MG-81. Read more about my rotary tool,

A lot shinier MG-81
A lot shinier
A cleaner MG-81 cone
A cleaner cone
a little build up in the MG-81 threads still
a little build up in the threads still

The next thing to tackle was filing the knurling valleys with a triangle file to get any build up out. I knew it would be a very tedious task that would need a steady hand, and the fact that it’s a round object doesn’t help with the steadiness. I could have put it in a vice and rotated it occasionally but that didn’t sound like the best idea either. So I decided that I would make a cradle to hold it that I could set it and clamp it into the wood vice. It’s working out so well, I wish I would have thought to build one sooner.

cradle for the MG-81

I finished half of the knurling before I stopped, it really makes your fingers hurt.

Very long video

Day 3

Several days later I was finally able to sit down and work on this again. I finished up the last half of filing the knurling. Looking at it I decided that I would try some rust remover gel. I’ve not used this stuff before but I had had some difficulty getting the rust to come out of the valleys between the knurls. It looks like that pink slime you see in Ghostbusters and smells slightly like vinegar.

rust remover gel for MG-81
rust remover gel for MG-81

It worked pretty well, but it did take several treatments to get the result I wanted. It also made the metal want to flash rust very quickly. It’s funny because the direction say to remove as much rust as you can before using, the directions don’t inspire confidence.

Flash rust
Flash rust

Because the rust remover gel caused the metal to re-rust so rapidly I didn’t want to risk letting it sit over night to get worse. It was late at night and I really wanted to go to bed, but I know that I would not be able to sleep if I didn’t get it into a state where it wouldn’t rust more, which meant finishing it that night. Full speed ahead on getting it wrapped up. Another round of wire-wheel treatment really showed dramatic results.

Final wire wheel
Final wire wheel

No hesitation, I went straight from the wire-wheel to applying blueing. Only one treatment was needed to get the coloration correct (in my opinion). And then immediately coated it in Barricade.

Covered in shiny oil
MG-81 Covered in shiny oil

I let it soak up the Barricade over night and checked it in the morning. It was completely dry, it completely soaked up all of that Barricade, so I gave it another spray down. When I got home from work it had soaked up most of the second coat too. I wiped off the excess that was left and it really looked the part once that excess sheen was gone.

MG-81 Final Laying
Paint me like your French girls
MG-81 final standing
MG-81 final standing
Real MG-81 Compared to Todd's
Real MG-81 Compared to Todd’s
Before and After Standing MG-81
Before and After Standing
Before and After Laying
Before and After Laying

2 Replies to “MG-81 Flash Hider Restoration for Nick”

  1. mugatu says:

    Very nice. I was doing something very similar in tediousness removing JB Weld from the threads of a booster. It made it look like the threads had been worn down.
    I screwed it into my complete barrel jacket to try to revive the threads, if appearances were correct. I must have done that 100 times. I can’t image doing that with a hand file.

  2. […] never thought I would ever see one of these MG-81’s in person, they are that rare. Then Nick sent me his to restore and I thought that would be the last one I would see. I definitely didn’t think that I would […]

Leave a Reply

Your email address will not be published. Required fields are marked *