Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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How to best clean rust off a knife
Q. Hi
A couple days ago I found a knife that my father used to really love but it got all rusted and had all this dark stuff on it....I managed to get some of the rust off it by sharpening it but I can't get the rest off because they are too tough.....is there any household chemical or tool that I can use to finish cleaning the stains? Or anything that can help me remove it?
student - Fall River, Nova Scotia, Canada
2003
A. See letter 23762, except you'll probably have to start with a coarser grit sandpaper (220?), and BE VERY CAREFUL! Many a person has went to the hospital for cuts, severed fingers, knife thrown through leg by buffer, etc , trying to do exactly what you want to do.
Jason Aube- Flint, Michigan
2003
A. I too found a very old knife a few years back that was very rusty but I didn't use any chemicals, I just simply stuck it into the ground, blade first, about 20 times and it removed just about all of the dust I then got some course sandpaper for the tough stuff and then enabled it to get a mirror finish by using the finest sandpaper I could find! good luck with your knife
Andrew Stabler- Durham, England
2007
A. Go at it with vinegar ⇦in bulk on eBay or Amazon [affil links] and baking soda [in bulk on eBay or Amazon [affil links] . It works too.
Amy Alken- NYC, New York
January 11, 2008
A. Years ago there was a product out called Naval Jelly. I used it to fix the rust on my SCUBA truck. There is a similar product today in auto parts stores. I don't know what it is called but I assume it's the same kind of thing.
You paint it on, let it get gooey and then lift it off along with the rust which it goo-ifies. Then repeat until the rust is gone.
- Raleigh, North Carolina
March 27, 2009
Hi, Robbie. Some things haven't changed much. Here's a hot link to naval jelly
⇦ this on
eBay or
Amazon [affil links]
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 27, 2009
A. Another trick that works really well is to put the blade into a potato. Let it sit for a few days and then the rust will come off with a bit of steel wool.
Jonathan Tinsley- Belle Fourche, South Dakota
September 6, 2009
Q. I was given a nice nice set of forged knives for my kitchen. By accident they were put in the dishwasher which caused rust to each knife. How can I clean these without ruining them?
Becky McCurleyhomeowner - Newborn, Georgia
December 28, 2009
A. Regarding the forged kitchen knives.
Clean them with ultra fine steel wool, wash with warm/hot soap and water, dry immediately, and a light coating of an edible oil (mineral oil is what I'd suggest).
If there are any heavier corrosion deposits you're going to need to CAREFULLY sand those spots down with 500 and then 1000 grit sandpaper then clean and oil.
- Boone, North Carolina, USA
March 16, 2013
Q. Refinishing old M3 commando knife. Is it possible to plate the rusted blade of this knife with a layer of steel? What are the waste by-products? Would it be better to plate with zinc, buff then refinish with bake on paint finish?
Anthony zeller- mine hill, new jersey
March 14, 2013
A. Zinc !!
What a terrible thing to do to an old knife that did nothing to offend you.
You cannot plate steel.
To plate anything, you have to get rid of the pitting. The only practical way is by surface grinding. And when the pits are gone you have a practically new knife. Oil it and stop there.
Geoff Smith
Hampshire, England
First of two simultaneous responses -- March 16, 2013
Second of two simultaneous responses -- March 16, 2013
A. Regarding the M3 knife, firstly if it's a real antique, DON'T DO ANYTHING.
Find a proper company with experience in antiques take it to them and get them to give you options.
If it's a knife you like but don't want to sink a lot of money into then you're going to be better off cleaning and re-polishing it, then getting a good nickel or chrome plate done by a reputable shop, this also means that you're going to have to disassemble the knife.
If there are any parts where the corrosion has gone too far you will likely need to have them filled with a welder, ground flat annealed, and go through the heat treatment again.
None of which I'd suggest to a novice.
I'd highly suggest going over to
http://www.knifenetwork.com/forum/
and posting your question with pictures. The guys there will offer up a great deal of advice on how to take care of it, or might offer to help you do it yourself if you're nearby.
- Boone, North Carolina, USA
A. Hello Anthony,
You can't plate steel as steel. If you want a professional restoration you may want to seek out a Electroplating job shop in your area. Depending on the condition of the knife it may just need some rust removal, Electropolishing, sharpening and buffing. If it does need plating a semi bright Ni may be a good choice. Keep in mind once you plate the object it affects the authenticity and value if you ever want to sell it. Good Luck.
Process Engineer - Mesa, Arizona, USA
March 18, 2013
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