Let's talk rust removal (chemicals, electrolysis, etc)

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noob5,000,000
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Let's talk rust removal (chemicals, electrolysis, etc)

Post by noob5,000,000 »

During the restoration of my RX-7, I've encountered innumerable cases where I've had to remove surface rust from parts. For large, relatively flat parts, a wire wheel on a bench grinder is king, but for parts with many nooks and crannies that can't be accessed easily, submersion in rust-removal liquids is great.

I've had great success with a product called Evapo-Rust, but unfortunately it is pretty expensive when you have to use large quantities of it. I did a little research and discovered many people have had success with using citric acid dissolved in water. Anyone done that before and have advice to give? I also saw a video of a guy removing rust with a molasses and water solution :shock: :? .

Another method that interests me is electrolysis. Anyone done that before?

Any other rust removal methods to discuss?
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by six »

Have you tried Cola? I'm being serious.
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by potownrob »

six wrote:Have you tried Cola? I'm being serious.
Pepsi FTW :!:
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by theholycow »

I was going to write up an epic post but my situation is different, I'm more worried about frame rust and large parts.

I'm glad to hear that Evapo-Rust works but bummed about the cost. I wish I had some idea what can be used more cost-effectively. I'm surprised that it is costly when used as a dip; can't you keep re-using it?

What about doing as much mechanical removal as possible with all manner of wirebrushes and maybe sandblasting, then using naval jelly? Naval jelly (phosphoric acid gel) converts rust into a stable oxide material; if the rust was thick then supposedly you can just knock the resulting black oxide off and apply it again, until it doesn't come off anymore and that last trace of rust gets converted and seals itself into a protective layer ready for paint/undercoating.
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by theholycow »

Oxalic acid, electrolysis, and molasses described well in one thread:
http://www.survivalistboards.com/showth ... p?t=197299
Nice.
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by Rope-Pusher »

theholycow wrote:Oxalic acid, electrolysis, and molasses described well in one thread:
http://www.survivalistboards.com/showth ... p?t=197299
Nice.
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noob5,000,000
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by noob5,000,000 »

six wrote:Have you tried Cola? I'm being serious.
I have heard of that, but haven't tried it. I seem to recall it being tested on an episode of Mythbusters and being successful. I wonder how aggressive it is, though. I have a few parts that have rust scale buildup, I wonder if the cola would be acidic enough to remove it. I'll pick up a 2-liter one day and see what happens.
theholycow wrote: I'm glad to hear that Evapo-Rust works but bummed about the cost. I wish I had some idea what can be used more cost-effectively. I'm surprised that it is costly when used as a dip; can't you keep re-using it?
You can, but it eventually loses it magical powers. I once found out the hard way that if left alone for a long time (weeks-months), it turns into an incredibly thick black sludge :lol: .

it really is great, though. I'm not exaggerating when I use the term 'magic'. :lol:
theholycow wrote: What about doing as much mechanical removal as possible with all manner of wirebrushes and maybe sandblasting, then using naval jelly? Naval jelly (phosphoric acid gel) converts rust into a stable oxide material; if the rust was thick then supposedly you can just knock the resulting black oxide off and apply it again, until it doesn't come off anymore and that last trace of rust gets converted and seals itself into a protective layer ready for paint/undercoating.
I do have some naval jelly, but honestly haven't used it much. I'll work that into my routine as well.
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Re: Let's talk rust removal (chemicals, electrolysis, etc)

Post by Rope-Pusher »

noob5,000,000 wrote:I do have some navel jelly, but honestly haven't used it much. I'll work that into my routine as well.
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I'm sure this would help you get rid of that navel jelly. I heard that they really don't check anymore to see if you are a fan.
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