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I bought an old metal cabinet that needs some restoration work, maybe not the best idea for a guy with no DIY experience and two left hands. So first I asked at a paint shop how much it would be to do this professionally , but for the quoted price I could have bought two already restored cabinets of the same type, so that's not going to happen. I did some research on how to best approach this, and ended up with three different options.

  • At my local equivalent to home depot they said I should thoroughly remove all rust, sand to get an even surface, apply a primer, and then paint it in the color of my choice.
  • A shop that specializes in paints recommended that I should remove all loose material with a wire brush, and then paint the whole thing with paint of the "Hammerite" brand, which apparently includes rust protection and does not need a base coat.
  • basically every DYI site I found on the topic insisted that I would have to strip the cabinet to the bare metal to get an acceptable result.

Now that I have three opinions on how to prepare the cabinet for painting, I need to solicit a fourth to help me decide. I have already resigned to the fact that I cannot do a perfect job, but this will go into a living area, so it should look at least decent. I am not afraid of work, but my neighbours will probably kill me if I spend the next three days making noise with a sander, so if can get away with not removing the old paint completely it would be some relief (if not I will risk their wrath). Picture of the cabinet is attached. Thank you for any hints.

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    Do you have access to chemical paint strippers in your location? They're fairly nasty chemicals so not available everywhere. – Criggie May 3 at 11:41
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    @Criggie, I can get them, but I would be worried about disposal - I'm not allowed to put household hazardous waste into the garbage can, and for the foreseeable future I cannot get to any facility that collects chemical waste. – Eike Pierstorff May 3 at 12:33
  • First thoroughly degrease it. Then either sand the rusty areas down to bare metal, or (probably better) lightly sand to remove the loosest rust, then apply a "rust-converting primer" before painting. – Hot Licks May 4 at 21:16
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OK, so this is a classic prep-paint situation, on a metal thing which has alkyd (that's what its mom calls oil paint when it's in trouble) or possibly LPU paint. Definitely not latex, so we dodged that bullet. shudder

Latex paints are not for metal equipment like this. They will fail very quickly. However alkyds are very stinky. If you can't paint somewhere vented, then use a waterborne alkyd with synthetic for-latex brushes... but those are new, weird and I don't trust them.

Paint prep is a generally miserable job, and the picture postcard for a very basic rule about tools: Always use hand tools until you've achieved mastery of the hand tool. Only then, look at power tools, since you now have a well-caibrated sense of how you want to automate the job. I own a ton of power prep tools. That particular piece isn't bad, and I would probably leave them in the cabinet and go at it with hand wirebrushes and sanding blocks. I would go for a power wirebrush if there was determined rust there.

But based on the fact that this isn't very rusted, I'm guessing it lives in a low-rust-risk location, so you don't really need SSPC-SP10 surface prep; any residual leftover rust probably won't break out. You just need it aesthetically smooth.

Prep is about

a) Removing and neutralizing rust. For a low-risk situation like yours, I would use hand or power wire brushing and/or sanding, til very little remains, then hit it with a rust converter, which you paint on.
b) Smoothing the surface. That's what sanding is all about. Dry-sand, or wet-sand if you're worried about lead. Now, you also can use primer as a "filler", to fill in the low spots. Primer -> sand -> primer -> sand -> primer is SOP around my shop, and they make high-build primers specifically for this purpose. For deeper fills, you can use fairing (commonly called Bondo).
c) Roughening the surface. Fresh paint cannot stick to a glossy surface.
d) removing dust and dirt. Mostly dust from the above lol.
e) removing contaminants. Anything that'll mess up the paint - especially silicones, linseed oil, latex paint. I prefer to take the primer I'm applying and use its own diluent (the stuff you thin it with, i.e. paint thinner for Rustoleum).
A double-cloth wipedown works best, cloth #1 is wet with thinner, and cloth #2 is clean and dry and picks up the contaminants. Keep refreshing cloth #2, I prefer to graduate it to cloth #1.

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Now you prime that sucker. You need to coordinate the primer to be compatible with the topcoat, both chemically and aesthetically.

Decide whether brush or roller stipple is something you can live with. If not, you'll need to skill up on rattle-can spray jobs. They are easy to mess up with runs etc.

Rustoleum 7769 Rusty Metal Primer is the stuff you want. It performs WAY better than you'd expect for consumer tier stuff, it's available everywhere, and it won't kill you*. When I can't get a surface quite to SSPC-SP10, I use Rustoleum 7769, and then apply my industrial tier coatings. You still need the unit quite dry, so drive humidity in the room down as much as you can.

Despite Rustoleum's "Stops Rust" slogan, Rustoleum 7769 is the ONLY product that will do that, and only over fairly good prep.

Rustoleum is an alkyd and is Very Stinky stuff. There is no way to avoid it. Water-based paints just won't perform on metal machinery like this. And hardware stores are now trying to push you into a "waterborne alkyd" - hissss! booooo! Avoid!

Paint outdoors. Lay down and weight down a tarp first, and don't overspray anyone's car!

You only need Rusto 7769 on the bare metal or formerly rusty areas. If the old paint is solid, priming is not so urgent.

Nothing wrong with hand brushing. You must use a natural bristle brush, not the synthetic brushes for latex. Either buy a good'un and fastidiously clean it after every use, or I get cheapie "chip brushes" and just watch for bristles and pluck them out of the coat as it goes on.

With spray, you'll need to multi-coat the first layer (if you try to get it in 1, it'll run). Brush might not need a 2nd coat if you coat it well the first time.

If you're after a smooth finish, you can re-sand after the prime. But if you blow through to bare metal, you'll have to re-prime at least that area.

Now think about topcoat.

Rustoleum 7769 is too good not to use, but it leaves you with a deep brown. If you want a light finish, prepare for 3 more coats. Normally I use Rustoleum 7780 for the next coat, but I gather you don't want to buy yet another can of something, so I just say use a 3rd coat of topcoat. There is no such thing as a 1-coat topcoat, because a) it's opacity isn't that good, and b) your application isn't that perfect. Marketing lies!

Since you don't need to Rusto everywhere, you might make your first topcoat just over the brown areas.

Since this is equipment not a house, your topcoat should be an oil-based alkyd (i.e. not a "waterborne alkyd", yuck). Rustoleum's topcoats (the alkyd "High Performance Protective Enamel" ones, anyway) are perfectly adequate. On one hand, color choice is very limited; but on the other hand, a second can will match. Sherwin Williams will custom mix, but their second can will be a bit off. That's just a fact of small-scale color mixing.


* Unlike the 2-pack "have to wear a moon suit" mil-spec stuff you see on new airplanes, which is loaded with PBA or isocyanates, and doesn't work in cans, since you have to mix 3-4 chemicals and then spray it within an hour. It's pretty good primer, though.

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  • It depends on what the base metal is (e.g., galvanized: needs special paint), what type of paint was used and what you will use (can't paint oil over latex). Follow the directions on the specific can of paint you purchased knowing it's specifically for this application. - There's only two questions: what's it made out of, and what's on it now. – Mazura May 3 at 18:49
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    @Mazura That's non-galvanized steel, and it currently has an alkyd, LPU or powdercoat which is sufficiently aged that chemistry isn't going to matter. It's had a rough life, but not a rusty one. – Harper - Reinstate Monica May 3 at 19:02
  • If that helps narrowing down the type of paint, according to the seller the cabinet was made between 1920 and 1930 (to me it looks more like a 50s thing, but that's what he said), and it was made in Germany. – Eike Pierstorff May 4 at 10:12
  • If it's that old I would be very careful not to inhale any of the paint dust, it might contain lead, cadmium or other evil stuff. Wear a mask if you can get one. – alain May 4 at 17:19
  • I'd recommend removing the glass pane (and seal) from the door if possible before doing any of this. While you might be able to protect it from being painted with tape, it can be quite tricky to do that accurately enough without causing it to peel when removing the tape later. Also if you're using power tools for sanding, the vibration could cause it to shatter if it's old enough. You'll probably want a fresh seal around the glass anyhow, that stuff degrades over time. And it'll be a lot easier to prime and paint when you're not worried about it getting on the non-metal parts. – Darrel Hoffman May 4 at 17:58
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You don't need to go to bare metal on paint that is well adhered.

Hammerite has a particular "look" (a deliberately uneven, uniformly) surface which can help to hide surface defects under it - if that look is what you want. It's a common machine tool or toolbox finish - less of a common choice for the living room. But if you look at some and like it, that works.

Rather than annoy your neighbors all that much, hand sanding (mostly with some sort of block between your hand and the sandpaper) would be less noisy and unpleasant for you, not to mention them. It's also harder to go horribly wrong with "no DIY experience and two left hands," though use of a power sander can speed things up (but at the cost of noise, dust more aggressively spread around, and all the bits that are not quite reachable with the power sander, as well.)

The main secret to painting is that the preparation work is 90% of the work. If you get the surface smooth and clean through sanding (or wirebrushing followed by sanding) the paint job will go well. If you leave some bits rough and think that they won't show, they almost certainly will show (Hammerite modifies that slightly)

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    While one can mess up a job by hand, a power tool just gets you to the messed up point quicker... :) – Solar Mike May 3 at 11:36
  • I was aware of the "hammered" finish, but not that this applies to all hammerite paints (thought that was an option like e.g. the choice between matt and gloss), so I will have to look at this. Also yes, mechanized failure is always an option, so I will sand by hand. – Eike Pierstorff May 3 at 12:37
  • Some collaborating evidence: Where I worked, they had about a hundred green metal filing cabinets from the 1960s. About 40 years ago, without stripping the old paint, they painted them beige. They still looked great when I retired recently. – Mattman944 May 3 at 15:18
  • I suppose it's possible that Hammerite makes paints without that feature. The only times I've seen the brand, it's also been that finish, so they are linked in my mind. Presumably your paint store could tell you more. – Ecnerwal May 3 at 15:29
  • @Ecnerwal they make a 'smooth' finish, which doesn't have the hammered effect. The smooth paint is still quite thick like the hammered one, and still covers defects due to the thickness. I'd use it on a railing or something in the workshop rather than on something for the living room. – Pete Kirkham May 3 at 22:55
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If this is a personal project and the cabinet will not be on display in a public location at your business or something, I would recommend listening to the advice from the pros at the paint shop.

  • The "pro" support at Home Depot (or equivalent advisor) is employed by the biggest A-Z home improvement supplier; they give good advice and if you end up using (purchasing) additional products/tools rather than the minimum needed then they are doing their job properly.

  • The writers on the DIY sites may or may not be skilled and experienced craftsman, but whether they are or are not they have to assume that their readers have three left hands and experience in demolition rather than construction. They also have to worry about subscribers and reviews and clicks for ad revenue so they should error on the side of advising more work than is absolutely necessary in order to do the job properly rather than potentially viable "shortcuts" which could result in complaints.

  • The paint shop knows more about paint and painting then home depot and the DIY guys put together. They also are more familiar with new products and technologies before that knowledge trickles down to distributors and contractors. The fact that they are advising you to use just one type of paint indicates that it's really good stuff that does what it should; if you needed to strip the cabinet and prime it before painting they would gladly sell you on the rest of those supplies as well. They know that you aren't restoring the cabinet to sell as new or as part of a larger job for a customer whose expectations you need to satisfy; if the method they suggest isn't 100% as good as the longer route it's probably at least 90% (for a new DIY with two left hands that's not bad at all) and it might take significantly less time and effort especially for a beginner.

Disclaimer: I have 20+ years experience with home improvement and in the past have operated my own general contracting business. Painting is NOT my specialty I am just advising based on my experience dealing with the three sources of information you mentioned.

Good luck!

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    IME the Home Depot gang has no idea what they're doing, because contractors and trade specialty retailers troll Home Depot constantly and hire away anyone who's any good. On the DIY sites, the writers are usually random people like you or I, except there's no reputation system to detect and inoculate the site from horrible advisors. It's either chatroom noise, or it's optimized for Amazon affiliate revenue. – Harper - Reinstate Monica May 3 at 17:22
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    Hey, they are good at directing you to the correct DIY page on home depot dot com! Usually, at least – AmishNick May 3 at 17:33
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  1. remove loose/flaky/unsound existing paint and all rust/corrosion by scraping/wire-brushing/sanding
  2. sand smooth to desired level of appearance, de-gloss any glossy painted areas. NOTE- there is no need to remove all existing paint. Sand existing surfaces to the level of appearance needed. If you spend time sanding completely smooth then that will improve the final appearance. If you do not sand completely smooth, that will show under the new paint layers (especially if a glossy paint is used; glossy paints will make imperfections easier to see)
  3. apply primer. NOTE- primer is not necessary unless bare metal is showing after sanding
  4. apply new paint. TIPS- always use professional quality paint applicators if you want the best looking finish and follow paint manufacturer's directions.
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I can only copy on other suggestions.

I will just add that if this is your first project and you want to restore it nicely, it is really good to practice on something else in similar condition what you are willing to throw off.

Local scrapyards or garage sales/giveaways are quite good sources for training material.

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