How can I polish and rust-protect a steel file cabinet?

I asked a question on how to sand a steel file cabinet down to a mirror finish a couple of weeks ago and got a lot of great answers. I tried some of the suggestions. What worked best was an orbit sander, starting at 60 and going up to 400. At 400, I could see a pretty good reflection of myself with no scratches.

I could have made it perfect if I had kept doing that all over the whole file cabinet.

Unfortunately, it would have taken forever to get all the scratches out because while I was learning how to sand it and trying out different tools, different sanding techniques, I made too many scratches. For example I used a belt sander on one entire side, thinking that would be faster. It was faster, but it left deep cuts all over.
I had started by sanding off some of the paint with those metal brushes that you attach to a drill. Then when I tried to sand that section with the orbit sander, I couldn't get all the scratches out. Even using really coarse hand sandpaper didn't get the scratches out.

So instead of giving it a mirror finish, I decided to go over the whole thing with the metal brushes attached to a drill. See what it turned out like below. I am going to leave it like that.

So now I need to know how to finish it. I had been following these instructions but they are not working.
The rubbing compound does not disappear when you rub it. It is just smearing brown stuff all over the file cabinet. I do not know what the purpose of this is. It's not appearing to polish anything. It just makes a mess. So after rubbing it with cloths didn't get rid of it, I tried to wash it off. But that was an even worse mistake because now there are small rust spots all over even though I dried it with a dry cloth after washing the file cabinet. Also, washing it made it look dirtier. There are water streaks all over it now.

I went to Home Depot but I don't know what to buy. I don't want to ask any of the floor staff because they could just say anything and it might make things worse.
A guy at Parts Source told me I should use Metal Polish. He actually told me to go to a jeweller and get jewel polish, but then he suggested this Blue Magic Metal Polish Cream. I don't know if he's right or wrong.

So my questions are: How can I remove the brown rubbing compound? Washing didn't get all of it. Am I supposed to buff it off? Apparently you can't use water at this stage.
How am I supposed to clean off the mess I made when I was only trying to polish it and make it perfectly clean and shiny before coating it?
Assuming I can get it cleaned off and make all the rust spots disappear, what am I supposed to coat it with? How many coats?
Is there something you're supposed to do after you coat it? Such as do you polish it then? With what?

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jtobako7 years ago
Any of the polishing creams or rubbing compounds are very, very fine abrasives and won't take out scratches. They tend to be wax based, so you need a solvent to clean them up, something like acetone or kerosene (or soap). When you get what you want, you can seal it with some lacquer or other clear spray paint. Light coats, quick passes, and spray past the edges so you don't stop or slow down over the surface or you will get drips. Keep the area free of dust or you end up making sandpaper ; ( If you do end up with drips, you can sand them down and polish the sandpaper marks off, but it's a pain in the XXX.
i work with jewelry/metal. To get any metal to a mirror polish, it works in steps. Not gonna use fancy #'s and words, but in a nutshell: you start with a heaviest (roughest) grit sandpaper for metal. (it has carbide in it), then medium, etc...going down to lightest grit. Big scratches form, then medium grit erases big scratches, then lighter grit erases medium scratches etc. If you can't get a scratch out, then go back a step and forward again. Last step is the finishing...the mirror. using 3 types of compound (same idea as carbide sandpaper idea), use 3 different buffing wheels for each compound....critical you don't use same buffing wheel for all three compounds cause it would be like using 3 grits of sand paper at once...all jumbled. The compounds we use are solid...sort of like clay/ chalky soap consistency...come in bricks...last forever. a little goes a long way. I use a glorified dremmel doo dad...similar to what dentists use to drill. They are high speed. I sand by hand and buff with doo dad, thinga ma gig. Careful not to scald my fingers since metal gets hot from buffing. In a proper studio, i'd have a buffing wheel....machine with a giant buffing wheel...wheels are interchangeable for each compound. Oh and almost forgot....direction of sanding. important tip to know. Think wood...you don't sand in circles if you want and even finish...you sand with grain in one direction. With metal...it's different...you don't have grain and you can change direction between steps, but you always work in one back and forth direction at a time which "levels" the surface a little at a time. For example: I'm on the first step grit (roughest)...start sanding in one direction. I'm creating scratches all in one direction....suppose there is one deeper scratch that either pre-existed or formed as i'm sanding in that same direction and it's not coming out...solution is to then sand vertically to the horizontal deeper scratch....this action "erases" the groove by forming new ones that counter that one "grain" so to speak. Think of it like this: Sanding in these steps essentially does this to the surface...think backwards. First you're creating rows of deep grooves like rows in a field. The objective is to created the grooves in order to fill them back evenly. First a plough, then a rake, then a broom, then a brush etc. Does that make sense? Now soil is a poor analogy, but the process is the same. You are basically furrowing in scratches in an even direction with rougher/bigger grains of sand on a paper, then you switch to smaller grain in opposite direction which then start to "shave" off the tips of the tops of those even valleys you just created and the reason you work backwards is because the smaller/finer rocks can't burrow deeper/wider than the larger/rougher rocks did, they can only skim off the tips of those valleys which in turn then create newer valleys...only these are now less deep and the walls surrounding the spaces = (scratches/negative space) are closing in tighter and tighter. So you just keep cross hatching in this downgrading way till the valley is leveled and the soil is even with only positive space. The polishing part where you use cloth buffing wheels that are embedded with the compound which is basically made up of tiny abrasives or 'grains" held in a binder material b/c they are too small to stick to a piece of paper like the sand paper works since these grains are also invisible to the naked eye. Visible or not, they are there and work in the same step method as the sand paper, only difference is that the grooves they form are not visible to the naked eye. What you do see is a high gloss finish, getting glossier and glossier the more u work on it. Now keep in mind, i'm talking about small scale pieces so to apply this to furniture requires a lot of time and elbow grease especially if you'll be sanding by hand. When i sand, i am covering a lot of ground at once with the sand paper, so doing this evening on larger pieces of metal is what i see as a dilemma. Just so happens, that I am, for the first time, going to attempt to sand down an industrial metal piece of furniture. (dresser style/bin) I don't want a mirror finish ...i want it matte, dull and even. As to doing it by hand sounds crazy to me given the steps, so i'm trying to figure out what power tool would make this go faster. I have a mouse sander and i'm wondering if this would work. This piece also has surface rust and it was badly coated with a patina solution that gives it a rust-colored look. So i don't know if i should use a solvent first to remove that stuff or to just sand till my hand falls off. Any ideas? All i know is that if you sand a surface of metal using some sand paper rigged on to my dremmel, it ends up gouging it. So i too am trying to find out power too. works best.
Tamer,i'm new to this site and it's been a while since you asked about the furniture.Have you finished the piece to your liking? Would you still like some info on refinishing the piece?
noahbody_ (author) 7 years ago
Varsol got off most of the rubbing compound but some of it was stuck in the grooves. So I sanded off what the varsol couldn't get to. Then I sprayed it at least 10x with Tremclad Clear (Gloss). It took almost 3 cans. Now I have a lot of files to put away Photos of finished product
Re-design7 years ago
Get the swirls like you like it then spray the heck out of it with clear acrylic. That will seal it and keep if from rusting without adding any color to it. Acrylic won't yellow over time unless you really abuse it. It's looking much better than it was the last time you showed it to us. I'll bet you've put a ton of time and elbow grease into this project.
noahbody_ (author)  Re-design7 years ago
So clean it up, then redo some of the swirls if solvent doesn't get all the dirt/rust off. Then seal it immediately before too much dust settles on it. I worked on this on & off for over 2 weeks and am still not finished. It would probably have only taken 2 days if I had known exactly how to do this from the beginning. I'm reasonably happy with the way it is turning out.
That, my friend, is often how things work when you're doing restoration work. I'm just now finishing up a restoration that took me about a month and a half to complete, between stripping out and replacing a rotted porch floor header and its fascia, resetting and the flooring near the entrance, rebuilding new a new staircase, rebuilding and refinishing a porch door, its storm insert, the door framing, and a nearby window and the structure that supports the window.... Last coats are going on the storm insert today... it's tedious but rewarding work. The swirls look pretty cool btw.
And before you chide yourself too much, remember that you originally thought the case was stainless steel, which would imo be just cause for polishing to a mirror finish :-)
Sounds like you need a good solvent, like D-limonene or somesuch. I'd probably spray it with NON WATER BASED PU - otherwise your handiwork will RUST badly. Steve
Agreed on both counts. Multiple coats with the Poly once you have the finish clean again.. the more the better, with a very gentle sanding and dusting between each coat. I'd shoot for at least 4 or five coats with enough time between coats to allow the surface to tack (almost dry but not quite). Personally, I wouldn't stop until I've applied about 10.
noahbody_ (author)  seandogue7 years ago
So what do I do to get the finish back to the way it was before I tried to polish it? Am I supposed to re-sand it? Or is this what the solvent is for? Is solvent the same as PU/poly? Should I use varsol or CLR or something like that?
PU is, I believe, Shorthand for PolyUretheane, but Steve will need to confirm.

The solvent is whatever the place that sold you the compound (that you put on the surface, that won't come off) says will remove it. I'm not sure if it's wax base or what. But I wouldn't try sanding until you get it off, since it will likely just gum up the sandpaper.

If there's rust after you remove the compound, then you'll need to do a bit more sanding, then clean it off with a non aqueous solution like acetone. allow it to dry (acetone dries very rapidly), then give it its first coat of clear acrylic or poly, as soon as it feels dry to the touch, see if there are any bumps. If so, sand it VERY gently, then dust it off and apply the second coat..repeat.... Re-design makes a good point about clear acrylic not getting color with age, but ime it's abit more brittle...not sure which is *better. There always seems to be a tradeoff.
yup polyurethane. Steve
noahbody_ (author) 7 years ago
You've got some promising patterns there, how about giving-up on the polish and going for engine turning instead?

On a WHOLE cabinet. Ouch. Nice effect though. I thought about it for my Landrover. Steve
Big job there, but that's aluminium isn't it? L
I don't think the metal makes much difference, its making all those little swirls. Steve
Your vehicle isn't going to rust if it's non-ferrous. I fear this cabinet will go red/brown if it's not properly sealed. Do you think that some fine abrasive on the end of a drill (bit of sorts) would do it? Polishing it is looking like very hard work from what has been posted so far. L
Yes its ali, I thought you meant its harder to do on steel than ali, and there's nothing in it really. You stick ScotchBrite (tm) on a pieces of dowel and chuck it in an electric drill, and you're away. Steve
noahbody_ (author)  lemonie7 years ago
Thanks for the suggestion. I just found out what engine turning meant. That's basically what I'm trying to do here but of course I don't have the right tools or experience. I like how it came out anyways. After I figured out which tools I was going to use, it took something like a day to get it looking like shown in the photos. I hope I don't have to redo it to get the dirt and rust and water streaks out.