Removing Rust from Dive Knife

[Camerone]

You should never use steel wool on a stainless blade. Small pieces of steel will embed themselves into the surface of the stainless and cause it to rust. Bronze wool or stainless wool may be acceptable but the best material to use is green Scotchbrite.

Agreed. Trying to use steel wool to clean off a stainless part is about the worst thing you could do to that knife, and will only cause more rust in short order.

If you did make this mistake and used steel wool, you will need to passivate the knife to prevent future rust. The first step is cleaning thoroughly with a degreaser, like Simple Green, and then a thorough rinse. Wear gloves so you don't get skin oils on the blade.

Then, for stainless, passivation is done with a warm/hot solution of nitric acid. Depending on the grade of stainless used in making the knife, you could also do this in a strong citric acid solution (more environmentally friendly, and, generally, easier to obtain.) However, the citric acid passivations don't work nearly as well as the nitric acid ones and are still prone to rusting.

The folk rememdy of "Coca Cola" may work due to the phosphoric acid in the soda, but it's not particularly proven, and the concentration of acid is quite weak. It will take a very long time to be effective, if it works at all.

If you haven't damaged the stainless with steel wool, yet, stick to the Scotchbrite green as captndale suggests...

 

[HenrikBP]

My vote is for Coca-Cola; it takes time, but it's cheap, safe and easy to get your hands on

My cheap dive knife had gotten *very* rusty on a trip. Shop was supposed to rinse my gear, but I'm wondering ...

However, when I got home I dropped the knife in a Coca-cola bath and just left it there. About 24 hours later, I could wipe some of the rust stains off. It took about a week to remove it all, but I did get all of the rust off. Granted there was some pitting here and there, but not much at all.

Gave it a shot of K9 after giving the knife a final wash, rinse, dry.

I think Camerone's got it right about degreasing first. Don't know if Coca-Cola causes passivation - although that's what I've heard.

Henrik

 

[mikeyjoe]

Wow, this is great - everybody has their own way..... Learning some things.

Never would have thought about the steel wool issue.

My method is super fine sandpaper. My knives are working tools - if there are some fine scratches on them, I don't really care.....

I finish with a light coat of graphite lube/silicone lube/WD-40.....whatever happens to be closest to me at the time.

Don't forget to take the whole knife apart - you'll likely find rust under the two halves of the handle.

 

[Diver560]

I've not used it on my dive knife, but my golf clubs are like new after using some "Bar Keepers Friend". It took hardly any effort and was almost scary how good it actually worked. I bought this originally for my aluminum clad pots and pans (again "scary" good results).

Has anyone any bad results with this stuff for use on a diving knife? If no one say different, I would certainly try this product..... its cheep and available at places like Walmart, Bed Bath & Beyond, etc.

 

[mts0628]

I use WD-40 and a green scratch pad. As others may have said, even though the oxidation is gone, there will always be a weakness for re-oxidation if not properly cared for. Simple enough though.

But, if after all of your time, troubles, and elbow grease fail you or the results just aren't up to your specifications, not to fret. Just make a new one! I have made them (and I have two from Tobin); it's just a matter of which one I grab before diving. I don't store mine in the sheath though and they seem to last forever. if they didn't though, just throw it out and NEXT! DIY.

With kind regards,
Thomas

 

[SDAnderson]

So, I have a deep sea supply knife in a holder on my bc harness. It has rusted as I don't take it out of the holder after every dive after rinsing out my gear. Now it has rusted. I tried soaking it in vinegar, but it doesn't really seem to work, as the rust is still there.

What have folks done with normal household products to get rid of the rust?

Having failed at the whole ounce of prevention thing, are you actually going to try the pound of cure? Once rust starts it never stops so you can plan on an ongoing project keeping the knife rust-free - which is how you got where you are.

Ditch the knife and invest in trauma shears. They will cut anything a dive knife will and some things (spiderwire) a knife won't. If you want to fool around with coating them with Vaseline/WD40/Crisco/whatever, go for it, but they're cheap enough to throw in the trash when they start to rust. EMT shears don't work very well as a prybar but neither do most knives and what the heck are you using a prybar for while you're underwater?

 

[JLambus]

My 2 cents.....

I dont care how stainless it says it is, unless you are rinsing the knife separately from the sheath then allowing them to dry separately the coating the knife with silicone before replacing it... a stainless knife will pretty much always rust. Replace the rusty one with titanium... or H-1 ive heard is the knew wonder material... soon to replace titanium.

 

[pacchill]

I just toss mine out, and go to Chili's and get a new one. Apple wood bacon burgers, Margaritas, and dive knives.

 

[mustang_5l]

I simply used a wire wheel on my bench grinder. Took all the rust right off and there was no damage to the metal part of the knife. Even if you hit the plastic portion of the handle (for a quick blast) it shouldn't damage it too much. Just take it slow and steady and keep it at a light angle to the brushes. Don't press too hard. When you have removed all the scale coat the blade in a thin layer of WD-40 and wipe it off with a cloth. You can put it back in the sheath now and not have to worry about rust. Just keep rinsing it after your dive and treat it every now and then with the WD-40. If it is heavily pitted, just replace the knife.

 

[E.C.Hansen]

I use this stuff on anything that shows rust, and any metal I want to protect.

ballistol - The World's Most Use-ful & Environmentally Friendly Lubricant