Rust removal on an M40

[MAP]

Gents,

I purchased a rusted out shell of an M40 to convert into a lamp shade. Lots of rust flakes, pin holes and areas of very thin metal.

Without using electrolysis or chemical baths I was wondering what the most simple method would be to remove much of the excess rust. I don't care too much if it creates more holes or if all of the liner band falls out.

Was thinking just a bath in vinegar and a brush? Then finishing it with a coat of flat varnish or maybe something else.

Thoughts?

[Rescue190]

A chemical bath in oxalic acid is the easiest solution to your issue IMHO. Nothing to lose and is easy.
John

[MAP]

A chemical bath in oxalic acid is the easiest solution to your issue IMHO. Nothing to lose and is easy.
John

Thanks! I wanted to stay away from Oxalic if possible. Not sure how to use it or how to dispose of it and also not sure if it will take off too much rust. Thoughts?

[RustyRelics]

I've dealt with helmets like these numerous times. Just give it a good ol' spraying down with a garden hose, rub some dish soap on it, and use a steel wire brush to brush off anything that could be loose. Rinse, and check to see if there's any obnoxiously large rust nodules hanging around. If there is, and you don't want them there, gently tap at them with a hammer (GENTLY) until they fall off. Then get yourself a large bucket and put several bags of black tea in water, and soak your helmet in that. The tannic acid preserves the iron, preventing any more rust from eating away at the helmet, and it gives it a lovely brown/black look once it's done. Soak this for about 24 hours.

[MAP]

Thanks Rusty. That sounds simple enough.

[Mordecai]

I have had good results with citric acid mixed in water although you said you dont want to use a solution. I restored a P17 US relic helmet I bought for 20$ with citric acid mixed in water and it removes rust slowly but surely, it doesnt damage the metal at all compared to some other acids. In fact I decided to leave some of the rust on to simulate the sand mixed in with some of the paints to give it a texture while I hand painted a 'Tri-color' camouflage on it using oil based enamel paints. And its a harmless acid to pour down the drain or outside, you can usually find it for sale as people use it for canning tomatoes.

[MAP]

John has been kind enough to put my concerns at ease and gave me some tips and instructions.

Picked up a can of Oxalic acid from Amazon and now have it soking overnight

Will see how it turns out and then give it a tea bath to try to lock in the rust and then drill a hole to make a lamp shade out of it.

Will post boring photos when I'm done!

[AndyM35]

Looking forward to seeing the results Michael.

Not that I would advocate the use of Renaissance Wax on anything but a very relic conditioned item, I’ve found that it does appear to seal the surface and stops further degradation etc. The M35 below was given a dry brushing with a nylon scrubbing brush to remove loose rust and dirt and given a light coat on the rusted areas. Last time was 2020 and it’s still looking the same now.

[MAP]

I was thinking of Ren Wax as an option. Let's see how the Tea bath works. If still flakey I'll think about that.

[Mordecai]

I am quite interested in this 'tea bath' method as I have never heard of it before, looking forward to the results!
I use a mixure of Beeswax and Oil by slowly heating the Beeswax in a double boiler & slowly adding synthetic gear lubricant or really any refined oil to make a 'bore butter' I wipe just a little all over a surface and let it dry. I didnt use it when I repainted my P17 as I was going to paint it anyways but I have used it on relic items before. I also use it to wipe down my bayonets every so often.