What To Do About Blemishes Made From Blades In Sheaths?

[countyholster]

Hi folks! I'm a leather worker in Eugene, Oregon and have run across a problematic situation a couple of times with leather, making marks under or on the surface of fine steel blades. It's happened with a lower end production knife called 'The Seguaro Survival'. That time the rust was appearing before my eyes. It literally was like a viral growth and took considerable work to stop it before it did serious surface damage. I chalked that up to the quality of the blade.

Lately I had another blemish appear on a blade. This one was a high end custom knife. The customer called after having the blade in the sheath for a month and said two small blemishes have shown up. He tried using a metal surface polisher to no avail. In this sheath, I cured the constructed sheath in a low heat oven for plenty of time. I'd hoped this would take the offending chemicals or interaction away. The sheath is lined with a 3-4 Hermann Oak. Outer is 7-8 HO. I used Eco Flo brown on the outer and on the lining. At this point I must assume the fault is with the Eco Flo. My mentor, Dave Shelgren suggested not dying sheaths and only Neetsfoot them. This would stop it, but would lend to a restricted product offering. Any thoughts? Thanks in advance, John.

[barehandcustoms]

Tell the customer to oil their blades before storing them for months in a leather sheath..... I doubt your dye is causing the problem. To me it just sounds like two cases of improperly stored high carbon blades. Some of the expensive high carbon blades will grow a rust forest overnight if not stored properly. Ive seen Mora blades rust up in hours when I leave them wet.

I might be missing something but I really don't think your sheath is the problem unless you are using some funky product not mentioned in your post.

Edited July 23, 2014 by barehandcustoms

[Northmount]

Probably part of the reaction between iron and the tannin in the leather - helped along by your humid climate. Like vinegaroon. Do black/dark blue/grey spots form on the surface of the leather inside the sheath against the steel blade?

If so, I wonder if chrome tanned lining would prevent it. I think you have the opportunity here for a few experiments. Let us know what you learn.

Tom

[electrathon]

This would be a great question for Paul Zalesak (who ironically was teaching in Eugene last weekend). His knives are some of the best anyplace and being an obsessive compulsive university professor he will likely be able to explain it.

[tatsumi]

Barehand is right, Always good practice to not store the knife in the sheath for long periods or if you live in a high humid location its best to keep it out until use.

Obviously brings a storage issue for the user as in "so where do I put it then" but when all said and done knife owner ship is down to the owner, not the sheath maker and providing you have done all you can to prevent the issue there is little more you can do other than advise on good storage.

Proper oil for the blade is a must, one that's food safe as the last thing you want is some nasty oil which protects the sheath but ultimately rots or breaks down the leather. worth looking into for what's available near you to advise your customers.

[mtroyalguy]

Could you use Neets on the blades? We know that wont rot the leather lol.

[barehandcustoms]

Long as you aren't using it to cut food then you can use it. Keep in mind *most* neatsfoot oil now is just a mineral oil mixture and not actually the oil from cattle shin bones anymore.

Usually its a bit of actual neatsfoot oil with a bunch of mineral oil plus who knows what as an additive.

I have always used olive oil or regular vegetable cooking oil on my BK2. Never had any issues with it hurting the leather other than darkening it a bit on the inside.

Edited July 24, 2014 by barehandcustoms

[rawcustom]

First off a knife should be stored with it's leather sheath, not in it. Even stainless steels can rust and the chemicals from the tanning itself can lead to this, so leather treatment effects would only be secondary. The rate of oxidation on the blade will have to do with the steel composition, level of finish and surface treatment. A "high end" custom knife speaks nothing as to the steel used. Many knifemakers use basic high carbon steel such as 1095 and many of those would be labeled "high end". O1 is another very popular custom knife steel, and although it has a dash of alloy it will rust like crazy, the same as 1095. The sanded finish will play a major role as well. A mirror polished blade will resist rust far better than a belt sanded finish blade. Although it won't rust as fast, high carbon blades with a mirror polish still tend to stain, and will rust over time in the right environment. Lastly some of us will acid etch our non-stainless blades to mitigate the oxidation issues. Acid etching is the same as gun bluing whereas it requires an oiled surface to fully work.

Despite all the extra ramblings, you should NEVER NEVER store your knife in a leather sheath, or your rifle in a leather scabbard. Add or subtract the NEVER's on that statement depending on if you call "Rust" "Patina" and if you call "Stains" "Character".

One last note, I prefer waxes on blades over oils. I think you get longer wearing protection from a wax.