white vinegar derusting disaster

[ScrapMetal]

That is scary, the way vinegar destroyed your calipers/dividers! Thanks for posting that.
I have a good collection of calipers/dividers, some vintage Starrett. I only oil them or use ScotchBrite.
I take ultra care of my tools so any information on their care and maintenance is always welcome.


Evap O Rust looks interesting. Does anyone know what it is?
I've used white vinegar and lemon juice to remove mill scale from steel parts
but would never use it for tools. Too corrosive.



Thanks

This is from Evapo-rust's FAQ page:

EVAPO-RUST® works through selective chelation. This is a process in which a large synthetic molecule forms a bond with metals and holds them in solution. Most chelating agents bind many different metals. The active ingredient in EVAPO-RUST® bonds to iron exclusively. It can remove iron from iron oxide but is too weak to remove iron from steel where the iron is held much more strongly. Once the chelating agent has removed the iron, a sulfur bearing organic molecule pulls the iron away from the chelator and forms a ferric sulfate complex which remains water soluble. This frees the chelating agent to remove more iron from rust.

If you look at the MSDS this stuff is about as dangerous as cow's milk: :biggrin: http://www.evaporust.com/docs/MSDS Evaporust.pdf

I've seen the reason for the "etching" on a piece that isn't fully submerged as, and I paraphrase, "The line where the metal goes in to the liquid but is still in contact with the air continues to rust due to the moisture/air exposure. The Evapo-rust continues to remove the newly formed rust resulting in an "etched" line."

Another thing to watch out for is that it will remove bluing from guns (bluing is just a form of rust) as well as any paints that have iron oxide in them (haven't personally found any yet). Other than that, if used in accordance with the directions, the stuff is about perfect.

JMHO

-Ron

 

[sk1nner]

I work in a plating shop (specializing in landing gear) we deal with H.E. all day long (literally ) bake parts at 275 for a few hours after vinegar and that will relieve the hydrogen.

 

[sk1nner]

I also should ad that using electrolysis to de-rust can also cause H.E. Any springs that are being exposed should be done so in their un-sprung form or as close to it as possible. H.E. is usually only a problem with harder steels. Most plating specs call for a bake if the part is harder than 34(ish) HRC. A 375 bake can be used if you are 100% sure it is not carborized, that temp can ruin carborization.

 

[cazclocker]

+1 on Evapo Rust. It has become my no-fail go-to for rust removal. It does seem to leave a blackish deposit, though. But it buffs off easily. If I'm in a hurry, I have been using Ex-Rust by Kano Labs (same people that make Kroil) to dissolve rust. It works in UNDER a half hour, sometimes in around 10 minutes or so. It works so fast I always babysit it - I'll stand there and just set a timer or something and watch it work - you can see bubbles, like from the bottom of a champagne glass. But whether I use Evapo-Rust or Ex-Rust, I always follow with a thorough cold water rinse, followed immediately by 99% isopropyl alcohol, and compressor air blast to dry.
...Doug

 

[EmilioG]

+1 on Evapo Rust. It has become my no-fail go-to for rust removal. It does seem to leave a blackish deposit, though. But it buffs off easily. If I'm in a hurry, I have been using Ex-Rust by Kano Labs (same people that make Kroil) to dissolve rust. It works in UNDER a half hour, sometimes in around 10 minutes or so. It works so fast I always babysit it - I'll stand there and just set a timer or something and watch it work - you can see bubbles, like from the bottom of a champagne glass. But whether I use Evapo-Rust or Ex-Rust, I always follow with a thorough cold water rinse, followed immediately by 99% isopropyl alcohol, and compressor air blast to dry.
...Doug

What about files with rust? Whats the best way to remove rust without dulling them?

 

[cazclocker]

What about files with rust? Whats the best way to remove rust without dulling them?

Just soak them in Evapo Rust. It will dissolve the rust, and then stop when it hits the metal underneath. Whatever degree of sharpness was there on the file will still be there. Evapo Rust won't magically deposit new metal into pitted areas, but the pits and the rest of the metal will be rust-free. After removing rust from your files, maybe consider making a change on how you store them. You can keep them in drawers lined with VCI paper, or keep little absorbent packets in with them, or just do what I did - move to Arizona. Also, get a piece of plain chalk (steal it from your grandkid's teacher) and chalk up your files before using them. Stops them from loading with metal chips, because they're already loaded up with chalk. Then clean out the files with a file card.
...Doug

 

[Cobra]

Sorry for your luck. Make me think I will stick to the Evapo-Rust, even with the little extra cost.

 

[jpfabricator]

"Evapo-Rust is as harmless as cows milk"
But how does it taste when poured on Rice Krispies?

Jake Parker

 

[sdmuleman]

I'm surprised no one suggested electrolytic rust removal. I've done it on a few small parts and it's worked well - something like that I just get one of the 1 gal empty pain cans from the hardware store and use that as a tank, add water and some washing soda or whatever (I use boax since I haven't found washing soda locally), then suspend the part in it (make sure it's not touching the can) and hook up to power. Haven't tried any spring steel, but I'd expect it would work fine.

 

[John Hasler]

I'm surprised no one suggested electrolytic rust removal. I've done it on a few small parts and it's worked well - something like that I just get one of the 1 gal empty pain cans from the hardware store and use that as a tank, add water and some washing soda or whatever (I use boax since I haven't found washing soda locally), then suspend the part in it (make sure it's not touching the can) and hook up to power. Haven't tried any spring steel, but I'd expect it would work fine.

That is at least as likely to cause stress corrosion and/or hydrogen embrittlement as vinegar.