Hello there,

Phosphoric acid H3PO4 is your best bet, since it turns iron oxide (rust) into ferric phosphate (kind of black coating which prevents oxidation,you can scrape it off if you want), this method is mostly used on rusty motorbike gas tanks, since it prevets oxidation from happening again.

For smaller stuff like screws i just use plain vinegar, tho this will eat away any kind of paint or shiny coating, same as phosphoric acid.

And for something that cannot be seen i use just use mechanical way of removal, and then clean the area with vinegard and isopropanol.

And for the "will it oxide again question", yes but it will propably take a lot of time(depends on humidity and salts in air) rust proofing paint is your best bet, like rustoleum. Or use something oily, way cheaper works, the same but will attract nasties. 😊

Agreeing with most of the above. Phosphoric acid is what the pros use. There are prepared solutions, usually sold under names like "Rust Wash" etc. The ferric phosphate residues can usually be wiped away with a wet rag.

At home I prefer citric acid over vinegar. It's easy to get hold of (the spice rack at the grocery store), doesn't smell as bad as vinegar, and if you heat it to close to a boil, it'll be incredibly efficient. The ferric citrate residues are slightly soluble in water, and pretty easy to get rid of.

When it comes to proofing against future corrosion, I'd also just use regular motor oil or something equivalent, when it's sheet metal in an indoor environment. A few drops on a rag and some rubbing will leave an oil film enough to prevent corrosion.

As for phosphoric acid, save your money and just use cola (light or zero, as you don't want sugar in it). Cola is mainly made of phosphoric acid and works great for removing rust.

Most ISA/PCI cards that I get have some degree of rust/scuffing on their metalic brackets and on the shell of their D-Sub connectors. In most cases, paste polish works wonders, either by hand or with a felt wheel attached to my Dremel. But when there's too much rust, the above method cannot remove it all, so thanks for the tips - next rusted backplate will go directly in my Coke glass 😀

Vinegar heavy hot sauce works for mild rust. It's handy for some applications because it's thicker and more persistent than most alternatives.

So... I do a lot of auto detailing for fun, and there is a product called Sonax Full Effect that i use on my wheels. It's designed to bind with iron particles in brake dust. I've soaked rusty bits in this stuff (just spray it on and let it sit for a while) and it does a great job.

Sorry all for necro'ing this thread but I've been looking for a solution to my question all day without any clear advice.

How do I clean the rust off of the actual vga port of a pci video card? It works but it's getting rough to plug into and i don't want flakes to get into the case or pins etc.

Should i protect it somehow after?

Clean it off like they say then there are a couple of things you can do to protect the port afterwards. Some machine oil on a cloth and a thin coating on the area per Violett'Blossomand kaputnik instructions will stop the rust. If you want something less sticky though, then you could spary it with these https://www.amazon.co.uk/s?k=clear+coat+spray … s_ts-doa-p_1_13. Just cover up the parts that dont need it with paper.

If we're going necro a question on my part:

Options for rusty iron are clear. What about copper? I have some old heatsinks that are pretty tarnished. I tried phosphoric acid. So long as the copper was underneath the surface it looked beautifully rejuvenated, but the instant it made contact with atmosphere it started discolouring again. I'm aware of Brasso-type stuff, but a bit worried of using that on things that go into a computer case, and it needs to be rubbed in, which is hardly practical in between the hundreds of vanes of a heatsink. Any suggestions?

vinegar should usually be fine for copper, don't expect to always get the shine back though.

Bar keepers friend is good for brass and comes in small white granules, you could make a paste with it I suppose and a tooth brush for scrubbing it down.

https://www.amazon.co.uk/Bar-Keepers-Friend-S … sc=1&th=1&psc=1

For copper, I find that ketchup works best 🤣. I clean my copper CPU waterblocks and heatsink bottoms that way. Makes them look brand new and shiny. I saw it in a few different articles on how to clean copper about 10 years ago. I guess the combination of tomato acidity + vinegar + salt in the ketchup is a near perfect formula for getting rid of copper oxides. Lemon juice + salt also works, but it is a little more harsh and should only be used if the copper is in really bad shape. For the ketchup method, I just smear it all over the copper, let it sit for 20-30min, then rinse it off. Sometimes a toothbrush helps if you're cleaning something that has a lot of ridges like the inside of a copper waterblock. For some delicate Zalman coolers with a ton of fins, I take the fan out, then soak it in ketchup for about an hour.. rinse it off and it looks new again.

wiretap wrote on 2021-03-11, 15:55:

For copper, I find that ketchup works best 🤣. I clean my copper CPU waterblocks and heatsink bottoms that way. Makes them look brand new and shiny. I saw it in a few different articles on how to clean copper about 10 years ago. I guess the combination of tomato acidity + vinegar + salt in the ketchup is a near perfect formula for getting rid of copper oxides. Lemon juice + salt also works, but it is a little more harsh and should only be used if the copper is in really bad shape. For the ketchup method, I just smear it all over the copper, let it sit for 20-30min, then rinse it off. Sometimes a toothbrush helps if you're cleaning something that has a lot of ridges like the inside of a copper waterblock. For some delicate Zalman coolers with a ton of fins, I take the fan out, then soak it in ketchup for about an hour.. rinse it off and it looks new again.

Wish I could say the same when I spill tomato sauce down my white T-shirts. 🤣

wiretap wrote on 2021-03-11, 15:55:

For copper, I find that ketchup works best 🤣. I clean my copper CPU waterblocks and heatsink bottoms that way. Makes them look brand new and shiny. I saw it in a few different articles on how to clean copper about 10 years ago. I guess the combination of tomato acidity + vinegar + salt in the ketchup is a near perfect formula for getting rid of copper oxides. Lemon juice + salt also works, but it is a little more harsh and should only be used if the copper is in really bad shape. For the ketchup method, I just smear it all over the copper, let it sit for 20-30min, then rinse it off. Sometimes a toothbrush helps if you're cleaning something that has a lot of ridges like the inside of a copper waterblock. For some delicate Zalman coolers with a ton of fins, I take the fan out, then soak it in ketchup for about an hour.. rinse it off and it looks new again.

Second this.
Only use I've found for that sugary stuff the kids like to eat.

That turned out nice. The first time I covered a heatsink in ketchup, I was like wtf am I doing. haha

wiretap wrote on 2021-03-11, 16:42:

That turned out nice. The first time I covered a heatsink in ketchup, I was like wtf am I doing. haha

All good until you try to eat it . 😉

Seriously, that's a good trick . I remember when I was a kid and we would leave pennies in a mix of vinegar and salt for a few minutes to "rejuvenate" them .
You basically get hydrochloric acid (diluted, because vinegar is usually not very concentrated) .

See https://www.chemicalaid.com/tools/equationbal … 3COO%29+%2B+HCl

bofh.fromhell wrote on 2021-03-11, 16:21:

Second this. Only use I've found for that sugary stuff the kids like to eat. […]
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wiretap wrote on 2021-03-11, 15:55:

For copper, I find that ketchup works best 🤣. I clean my copper CPU waterblocks and heatsink bottoms that way. Makes them look brand new and shiny. I saw it in a few different articles on how to clean copper about 10 years ago. I guess the combination of tomato acidity + vinegar + salt in the ketchup is a near perfect formula for getting rid of copper oxides. Lemon juice + salt also works, but it is a little more harsh and should only be used if the copper is in really bad shape. For the ketchup method, I just smear it all over the copper, let it sit for 20-30min, then rinse it off. Sometimes a toothbrush helps if you're cleaning something that has a lot of ridges like the inside of a copper waterblock. For some delicate Zalman coolers with a ton of fins, I take the fan out, then soak it in ketchup for about an hour.. rinse it off and it looks new again.

Second this.
Only use I've found for that sugary stuff the kids like to eat.

That's exactly my use case. Time to get some ketchup 😀