remedy? rusting rescue knife

Advice
#41

Thanks for keeping it classy down there
in Texas. They need people like you calling others ‘tools’ to keep their image bright. Good work patriot!

#42

It would take a LOT of Coke…
…as you would have to keep renewing it, but given enough time (months or years) you could probably dissolve an entire knife if you really wanted to.



FWIW, I often use a citric acid solution for removing rust from old tools (planes, chisels, etc.) I’m restoring. It does a great job of removing rust without damaging the underlying metal. An hour or two of soaking is usually enough to clean tools down to bare metal. Citric acid powder is available at brewing and wine making suppliers.

#43

That was lame.
I’m embarrassed FOR you.

#44

Brian, that’s a good tip – citric acid

#45

Vinegar - Practice
Two points here, one a reply and the other an ahah.



My Gerber River Shorty was showing moderate rust and I looked to the Internet for answers. I found a recommendation to use vinegar for rust removal. Wrapped the blade in a vinegar-soaked rag and left it in a baggy overnight. Most of the rust wiped off easily the next day. The remaining rust came off with vigorous scrubbing.



An ahah that hit me while I was doig this is that one side of this knife is blunt. I need to practice taking out this knife while under water and make a cut. Otherwise it isn’t going to be much good when I really need it


#46

I’ve tried other methods…
…such as electrolysis, but I found that to be too complicated, messy and slow, plus you have the dual dangers of using electricity around water and you’re creating hydrogen gas in the process.



With citric acid, you simply mix the powder with water, stir it for a minute and drop the parts in. The solution is pretty benign and you can even drink it, before using it to clean tools of course (it tastes like Sweet Tarts). For parts that are heavily rusted, I’ll brush or scrape off any loose rust before soaking them. An occasional brushing while soaking will remove loosened material and allow the solution to get deep into the surface and remove all traces of rust. Once they’re rust-free, I rinse them under COLD* water then immediately hit them with WD-40 or a similar product to protect the clean and highly-reactive surface.



BTW, with any rust removal method, you should remove grease and oil before beginning the rust removal process.




  • If you use hot water, the metal will begin to rust again immediately (especially with cast iron) and you’ll actually see the surface turn yellow. It wipes off when you oil or wax it, but it’s a bit disconcerting to see the immediate change.
#47

remove grease and oil with?
Soap and water? Or a wipe with a cloth?

Just asking in case this is something tricky and not obvious.

g

#48

Acid must be the key
That must be why vinegar worked for me. Vinegar is acidic, right? Interesting that citric acid is available as powder. Who’d a thought?



~~Chip

#49

Any degreaser will work
Soap and water will work in some cases, but I typically use solvents like lacquer thinner, white gasoline, acetone, etc. Just don’t use paint thinner (mineral spirits), as it leaves an oily residue that inhibits cleaning.



Maybe next time I’ll try a citrus cleaner, since they’re good degreasers, environmentally friendly and they’re acidic, so they will jump-start the rust removal process.

#50

Exactly

– Last Updated: Aug-19-10 2:41 PM EST –

Any mild acid will probably work. Citric has the advantage of working quickly and it has almost no odor, unlike vinegar. Vinegar is certainly easier to find, however.