Rust Removal From Mateing Machined Surfaces
 

Well with all the talent here I am hoping to get some direction to clean up 2 blistered and pock marked machined surfaces.

They are the 15 degreed angled surfaces that are the fixed and rotating parts of my 1942 Mosler Money chest.

This thing is a beast at 1600 pounds and the 20" round door must be in the hundreds of pounds range. It was poorly stored in a basement and the once beautiful polished surfaces suffered a lot of corrosion. Due to this I can't rotate the door closed, even when it was new anything on the surface could prevent rotating open/closed.

I tried a few things but doesn't make a super smooth surface. So far tried scraping with razor blades than steelwool with WD40 and than a brass wire wheel.

Material is cast steel.

First picture is after I did a clear coat (patina look) and second after I painted the interior gloss white and third is a picture of the opening. I need to get maybe a close up of the area of concern.

Thanks in advance

Sawyer

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How did you get it out of the basement??

WOW! So it's basically just a huge, heavy safe, but with very high tolerances.

I'd say the way to go is reverse electrolysis which is what lots of folks use when restoring rusty old tools, but thats too big and too heavy.

I feel like a solution that should work would be sanding with a very fine grit wet/dry sandpaper. Rather than using water (the norm when wet sanding), I'd use something like Windex (often used when sharpening tools like plane blades and chisels) or a cutting oil, like the oil used in some sharpening systems (like Lansky). I'd probably use the sand paper in conjunction with a block or curved surface to help keep things flat.

Sanding should get you a smooth surface (better than steel wool or a wire brush, I would think).

And then immediately afterwards, a light coat of either oil or wax (wax is often used to protect old tools, but oil should also work).

Oil it.
Wire wheel
Etc

I got a guy to get it on a pallet and drag it up planks with a little Bobcat skid steerer before I picked it up..

I didn't know the weight at the time and when we loaded it in the bed of a pickup it really lowered the back down.

Well I knew it was over 1200 pounds as I couldn't pick it up with my compact tractor.

Lots of cribbing, pry bars and pipes to get it inside my garage.

Oh and the worst part was he rolled the safe over on its side onto the pallet and when I got it close to my overhead door I used my engine hoist and more cribbing to rotate it back on it's bottom. I did take advantage to paint the bottom first.

This thing is 24x24x24 of cast steel.

Sawyer

Try something like Rust-oleum rust dissolver gel, POR 15 also makes some products.

When I restored my drillpress I wet sanded the table portion with a petroleum-based product. I think it was pb blaster I had sitting around. It worked amazingly and has not rerusted in several years.

I'd be concerned that it would be difficult to neutralize/clean afterwards. Maybe the stuff that converts rust to a black coating? But I suspect that would still require some sanding (before or or possible and after application)

I would use pure phosphoric acid to dissolve the iron oxide. Don’t use those “rust converters” because they have an added polymer that builds up and acts as a coating. Once you get the steel good and clean you can use wax or oil to coat the steel and prevent further rust.

I assume you want to be very sure that you then neutralize any acid with a base (baking soda) and then thoroughly rinse any remnants of the acid and/or base away, and then get rid of the water (so it doesn't create more/new rust).

There's also "evaporust" which is a product that gets a lot of press these days for various things.

I'd be concerned with most caustic chemical solutions (acid, base). I believe that using an acid will potentially cause new damage (in addition to what was caused by the rust).

The acids are going to cause a lot of problems for the newly painted interior. Wet sanding should be pretty safe.

I use the Rust oleum rust dissolver for paint touch ups on my truck and other cars, really not that strong, has not affected the nearby paint. Not like it's going to eat a hole through anything.

I'd sand blast it then strip it down to get all the bits clean then refinish it.

I’m sorry. I don’t think I was clear. By “pure” I didn’t mean high molarity, I meant unadulterated by polymers or other protective finishes. I don’t know the molarity of pre-paint acid washes is, but use something like that. It will convert the iron oxide to a softer, more easily removed compound. Basically you don’t want the product to remove the rust that obstructs free movement just to replace it with something else that will obstruct free movement of the door against the jamb. You want to remove the rust, then add your own protectant that is also lubricating.

First. This is super cool. Second. You either need abrasives or chemicals.

What about dry ice blasting? A wild shot.

I do know that I cleaned up my rusted table saw with green scotch bright and wd40. Then cleaned off with simple green. Wiped super clean and waxed with Johnson’s paste wax (RIP! Miss that stuff). Table top was worse than what you have and has been great for years.

If you don't have a sand blaster: Mild acetic acid (vinegar) is where I'd start. Wire brush to remove the loose stuff, soak with vinegar, wait a day, repeat. This will remove quite a bit of it without damaging the surrounding metal. Once it's mostly clean, move to a red Scotchbrite wheel and some phosphoric acid metal prep.

Is laser rust removal affordable and widely available yet?

I'm on an "old tools sales" group on Facebook, and cans of old Johnson's paste wax go for $50-75. It's crazy.

We prep our our cast iron table saws with a simple 3-400 grit wet and dry sand paper (we just use WD40) wrapped around a block of wood to get surface rust out. The wood block keeps everything flat. We aren't removing a lot of materials here just surface rust.

Wow thanks for all the current input. I did try to razor blade the blisters off and it does take it down to see the factory grind marks, Not very smooth but was a start.

I can't use any rust converters as they will fill in the rotating gap.

I have most of the products mentioned here kicking around so I'll start there.

I did the paint as this thing is sitting in the way and where I need to move it I can work on the door opening.

This is Cast Steel and not Iron, amazing as it is cast together than opening is machined, the inside and exterior have rough mold marking and chisel marks all over while removing the casting material.

I think maybe I'll try blade scrapping, than oil (wet) sand and see if vinegar would help clean the craters. I have lots of 3M wet o dry from 320 - 3000 so I'll use 320 - 400 grit and see where that gets me.

I did try a wire brush by hand and one on my die grinder and they really didn't have much impact

I'll keep you all posted as I throw whatever I can at it.

Sawyer

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Good luck, and definitely keep us posted. That thing is cool!

If you need to sand a curved surface, wrap the sand paper around a dowel or something round.

You could also try using balled up aluminum foil to rub the surfaces. It'll act like a clay bar does on paint.

Laser rust removal would work! Cost or availability? ... Who knows?

Nothing to add, sorry, but what a terrific project - I can’t wait to see how this turns out.

Hi all, Made a good progress on this beast. I took some of the ideas here and here is the result.

I used the razor blade method to remove the surface rust. Didn't ever try this before but this portion for cleaning worked. The machined surface was harder than the blade and the blistered oxidized surface was softer. Scrapped it until no resistance was felt and sounded smoother.

Than I made up paper towels folded to about 1 3/4 wide soaked them in 5% white vinegar and held them on the surface with magnets. The vinegar/towel patch stayed on for 2 hours and turned the surface black. Next treatment was a steel wool and WD40 scrub which cleaned up the surface to a dull steel color.

Final was a WD40 wet sand with first 320 grit and followed up with 600. Came out good but the pock marks which are very minor still are slightly darker than the rest of the surface. Followed with a light coat of sewing machine oil.

When I first tried to rotate the door it never did, After the razor blade it rotated about an inch, after the polishing it finally rotated to the fully closed position.

The other process was to separate the door from the hinge (250# +/-) to clean the old 84 year old grease and give it a fresh lube. The tolerances are so tight that when I used regular chaulk to check for any rub points the chaulk actually filled the gap enough that I needed to really put some pressure on the handle to rotate back open.

I decided to keep the patina finish on the exterior and gloss white the interior as it was so dark in the original dark green color.

I still need to paint the lug area of the door silver and refurbish the combination lock.

Thank you all for the suggestions.

Sawyer

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Great job. Glad that you got it licked. Thanks for updating us.

I'll give you $20 for the safe if you can ship it for less than $50! :D ;)

I'll stick a Forever Stamp on it drop it off and when you receive it the Post Office will expect you to make up the difference.

It is just under 1600# but the over 12 inch package might be the upcharge issue.

Curious...what did you use for the pivot lube? I'd have suggested superlube...same synthetic grease that snap-on uses in ratchets.

I tested 3 different greases, Valvolene wheel bearing, Magnalube and a white colored teflon based grease with no label.

Hillbilly testing was hot (warm oven), cold (fridge) and dirt (saw dust) Just to see what stayed in place and didn't get too thich when cold. The white teflon grease held up the best so that is what I used on the rotating door.

The door hinges and handle have oil cups, the type with a spring loaded center. I first used Kroil, than flushed with WD40 until it was seeping out less rusty color and than white lithium.

The machined surface I used sewing machine oil as I figured it would not gum up and attract dust. There are many cases of these safes not opening due to oil drying up.

If I had some 0 weight auto oil I might have tried that but in either case I'm not sure what happens in time that might glue the door in place. The door ramps it self in such tight tolerances to prevent any liquid making its way inside it really creates a metal to metal seal.

Yearly maintenance as per the tag on the door will be followed at minimum. Or if during use I feel a bit more drag it will be done than.

Sawyer

This?

https://www.super-lube.com/silicone-lubricating-brake-grease-with-syncolon

About $8-16k+ for non professional. Dang.

Yep. Good stuff. Some months ago, I cleaned & then relubed all my old Craftsperson and New Britian ratchets with it. Really smoothed them up.

Also not to mention if I tried that I wouldn't have anything left to secure in it.

pwd72s I looked closer at the deteriorated label on the container and I can barely make out Permatex and Teflon. It is a white almost Vaseline viscosity and it seem to be the least thick of my off the shelf stock.

Sawyer