Knives rusting...

(Having nothing to do, I decide to irritate the ETS folks...)

As an intro - I'm from Guyana, South America. It's a poor 3rd world country that's struggling to come to the internet age - oh wait - we're struggling to feed ourselves sometimes.

More than 80% of the population live on the coastal plain and this poses certain problems for carbon steel knives. I've read all over about the advantages of carbon steel and the fact that it'll rust easily, but could not really find anything about how much and how fast this rusting will occur.

I purchased a basic carbon steel mora knife (from Ragnar) and decided to check out this rusting problem with the knife. I know that this does not confirm to the standards of a scientific experiment, so please do not treat it as such. This is purely a result of me having too much time on my hands and a digital camera.

Please comment. If we could have a comprehensive post about carbon steel knives and the rusting problem it'll be a great help to beginners or persons who never handled these knives before.

Also, please feel free to copy/distribute/etc. if you wish. Remember the reason I did this was that I couldn't find any similar info online and I had no idea about carbon steel's properties related to this rusting problem.

http://rapidshare.com/files/93732436/Carbon_Steel_Kinfe_Rusts.pdf

Nas.

Welcome to the campfire Naseem!!!!

For an average joe like me living in the middle of the U.S., the chance to chat with someone in Guyana is really pretty exciting. I like hearing from all my fellow ETS'ers around the globe.

As others have said, carbon steel knives have been in use on our small planet for centuries and folks have made them work. Personally, I prefer a high-quality stainless steel, such as Doug's Rittergrips.

My best advice is to keep the blades coated with oil or wax. If you're using them to prepare food, then a THIN coating of light high quality mineral oil might do best for the body - as opposed to oils with who-knows-what in it.

Ken K.

Hey Naseem, welcome to the campfire.

I found a product that works pretty darn good for protecting carbon steel knives in wet climates.

http://sentrysolutions.com/welcome.shtml

They seel a product called tuf cloth, which is a cloth impregnated with a substance that bonds to the metal molecularly and is pretty durable. I don't know how difficult it is for you, but you can order from their website, and it is not terribly expensive.

None of my best fixed blade knives are stainless, and some have rusted. Since I started using this tuf cloth stuff, I have no more problems with rust/corrosion on them or my blued firearms.

As an alternative, you can season carbon steel knives much the same as you would cast iron cookware. Simply coat the blade lightly with vegetable oil, shortening, lard, or beef tallow. Using a torch, lighter, candle or small flaming fire, you can scorch the fat on the blade. It will turn brown, then shiny black, and will seal the metal well. You can season the blade all the to the edge, just be prudent about how you apply the heat so you don't hurt the temper of the steel at all. You'll have to do this after heavy use, as the coating will wear and open up to expose the metal, and even at that the coating is not entirely impervious, but it will help a lot.

I had a former shipmate that used to use gun-bluing on his carbon steel knives. Seemed to work well. I switched to msotly folders, when I began working mostly brown-water. So, I never tried it.

I use Fluid Film to weatherproof my blades. If it's good enough for submarine ballast tanks (and available at the hardware store) it's good enough for me.

Good looking "non scientific" study. I remember seeing a similar study done on another forum. Its purpose was to test which oils work best. I don't know if anyone has a link to it, but it showed how long it took for a carbon steel ingot to rust when coated with various substances.

I find that after a carbon steel knife builds up a good patina, it resists rusting more than a virgin steel blade. It still isn't rust proof though, if it sits in water it will start to rust. Really though, the best way to keep rust as bay on a carbon steel knives has always been keeping it dry with a light coating of oil or grease. Even a light coating of melted animal fat works.

In modern times more expensive carbon steel knives are often sold with some kind of Teflon based coating. This coating has basically the same purpose as the oil, coating the blade and resisting rust. Then all you have to worry about is the edge rusting until the coating fully wears off (which in my experience takes a long time if the coating is good).

Another modern option I've seen is a blade with stainless on the outside and a carbon steel core. They're probably the most expensive of the three, but are very rust resistant (except on the edge) and you don't have to worry about a coating wearing off.

With all that in mind, if you spend a lot a time around water it's tough to beat a blade made of a good stainless steel. It may not be able to do that cool sparker thing with a rock and it may not be as easy to sharpen as a carbon steel blade, but it can do everything else as good, or better, and it's low maintenance. Most of the blades I use now are made of stainless or a semi-stainless steel and I don't feel I'm really at much of a loss versus a carbon steel blade.

Stainless for on- and near-water, food prep. Carbon for general purpose where oils and coatings in food not an issue.

There's government "safe" then there's safe.

Each to their own.

I have used vetable oil on knives before but never seasoned them, I apply it fairly thick and leave it. The vegetable oil will form a sticky coating but will with stand long term storage without rusting. The down side is that you can use your knife with the caoting but it is better to clean the blade before use. The pro for this is the knife can be used on items that are going to be eaten.

I also have had good luck with Sentry Solutions products. Good results after a single use of a Tuf-Cloth and with repeated use the protection seems to get better. They have a complete interlocking system that is quite effective in tough situations. Like vulnerable carbon steels in salt water environments.

Use a thin coat of any vegetable or petroleum based oil/grease. It's really that simple. Experiment, find what works well for you. I use vaseline on my axe heads when putting them up for the season and canola oil on my knives. Again, just a thin coat works very well.


-JRJ

Good advice - I had heard about this but couldn't find how it was done. I remember something about using vinegar to coat with a patina - any idea about this and how the coating compares with the "seasoning" method?

I use stainless steel most of the time though. It works for everything I want to do. It's just that all the recommendations for carbon steel made me excited enough to spend some money...

Nas

Didn't mean to be too negative, but then, what is the minimum amd maximum daily allowance for teflon?

Naseem,
You can use vinegar, a potato, almost any acidic fruit or vegetable, lemon juice, etc., to form a "patina" on your carbon blade. I have spotty patinas forming on some of my carbon blades, but I have only done it on purpose for one knife (unfortunately, that knife had to go back to the manufacturer for a repair and they buffed it off! ). I kind of liked it when it had the patina, but it really looks nicer without. Maybe my method wasn't up to par....

Some say that this patina will help prevent rust. I can't vouch for that, but I would at least think that it helps prevent rust from settling in and pitting, giving you a little more time before you have to clean the blade well.