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Post by theforestninja on Sept 2, 2024 8:05:10 GMT
Hello, figured I'd share some rust prevention information I've read about while online.
Carbon steel has one big issue that one has to contend with to protect it and that's oxidation (aka rust). Keeping the metal dry from water and a light application of oil is the normal procedure. I've been using food grade mineral oil from the beginning and recently found improved alternatives.
People in Japan sometime use a special oil for their valuable Katanas called Choji oil. It seems to be a mixture of mineral oil along with a small amount of Clove oil added.
I found an article in which they made 2 types of mineral oil mixtures. One being made mineral oil, clove oil along with basil oil (CLB) and other with mineral oil, clove oil along with atlas cedar oil (CLA). They used the different mixes in varying concentrations of 0.5%, 1%, 1.5%, 2% and 2.5%. The 2.5% version being the most effective. The reference to that article is just below.
So I decided to make my own version of CLB 2.5% using:
Basil Essential Oil, Clove Essential Oil (Madagascar) and Mineral Oil (food-grade).
For acids, some people like professional Japanese sword polishers use a pinch of Sodium Carbonate in the water to keep the pH above 7 to reduce rusting. After doing some research I found an article on Sodium Citrate being excellent for slowing down rust on Carbon steel. It's what I use in my water when I sharpen and/ or polish my blades.
I hope this helps somebody protect their blades.
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mrstabby
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Post by mrstabby on Sept 2, 2024 9:04:59 GMT
I am skeptical that these additives work that much better in oil. Those were tested as additives in aqueous solution with an inorganic acid not as an oil stuck to the surface or versus plain mineral oil, petroleum jelly or wax. LINKI have seen choi oil tested against pure mineral oil and there was pretty much no difference under normal conditions. I am also wary of such essential oils since they are themselves often hygroscopic and contain compounds that can corrode steel (or even skin).
As to adding citrate to polishing solution, as I read the text it says they form a protective layer by adhering to the surface, while polishing you will constantly kick them off negating a lot of the effect. You can see in point 3.2 that it takes time to get this layer up, and if you disturb it all the time it's basically not better than leaving it out Putting the pH over 7 with baking/washing soda or using the citrate as buffer (for pH7 with Na2HPO4 for example) would likely help more than the citrate itself.
I don't mean any disrespect or want to be a nuisance. These are just my thoughts towards these publications. They are more about protecting water pipes and the such than they are about protecting bare steel blades, that's where museums have a lot more experience and they mostly use wax or lacquer.
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mrstabby
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Post by mrstabby on Sept 2, 2024 9:35:50 GMT
Oh, I forgot to say be careful, I found too basic a solution of citrate stains steel. At pH 7,5 I found it began to stain the steel greyish black. I am not sure if the same happens with a weak base since I use NaOH, just be careful. I have been experimenting with rust removing since it is a chelator like EDTA. Up to pH5 or so it pretty much behaves like an acid, at ~6,5 the orange complexes begin to form. I just don't have enough rusted samples to experiment...
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Post by larason2 on Sept 3, 2024 2:16:36 GMT
I have some choji oil, and it performs quite well for preventing rust. I'm not convinced it's better than ordinary mineral oil, but I use it on all my nihonto as it is traditional. I'm a bit suspicious of the other additives, as they are not traditional. Not to say they can't work, but I'm not sure it merits the extra cost. Usually just the oil soluble components are added to oil, any water soluble components migrate out with the water layer and are typically removed, at least as far as I'm aware!
Usually Japanese polishers only add sodium citrate to the water if they have acidic water, and only for steps they use hato. Hato are mildly acidic (in my tests 6.5), and many polishers have the slurry on the sword for an extended period. My tap water here is quite basic (8+), so I never bother with this. If I had acidic water though, I would. Virtually every other stone used for polishing is very basic, so there's no point using it for any other stone. Since you have a build up of clay and clay like particles on the sword's surface with Japanese traditional polishing, that inhibits rust pretty effectively. Still, the choji oil is used for protection.
So, I would agree with Mr. Stabby. Save yourself some money and trouble and just use mineral oil. Petroleum jelly is also sensible depending on the sword and your environment. Some swords have very acidic surfaces, where oil tends to bead and they will rust in a second. Peroleum jelly is sensible there, particularly in humid environments.
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Post by bwaze on Sept 3, 2024 8:34:47 GMT
I used Ballistol for all my uses - arms and armour protection, for nearly two decades. It is much better in rust prevention and ability to stay on steel surface than simple mineral oils. I also used Renaissance wax, but I hate the application process, so I don't use it very often.
But lately I grew weary of the smell of Ballistol - it lingers and is hard to get rid of it. So I started using Fluid Film - which also doesn't smell particularly nice (it is lanolin based, so it smells like sheep). But at least it dissipates quickly when using it in vented area. And I think it works even better than Ballistol.
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mrstabby
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Post by mrstabby on Sept 3, 2024 9:02:31 GMT
Yeah, Ballistols smell is pretty strong and has lots of staying power. It is one of the best rust protecting oils as long as it does not get directly wet since it creates emulsions with water and gets washed away relatively easily in my experience. It also tends to gum up if it collects anywhere (like if it forms a drop over time while the object is just laying there). One thing I found out recently, do you know hardwax oil for wood? It also works on metal! It creates an extremely hard coating on stuff. I have honestly not tested it longtime yet, but it's basically carnauba wax and linseed oil, it also sticks to steel relatively well (you can scratch it off but rubbing alone does nothing). It's much easier to apply than Renaissance Wax since it's a liquid but drying time is between 2-7days for full hardness, it is "hard enough" after 24 hours.
If you want to go crazy rust protection mode you can use transparent polyurethane lacquer (the 2 component version is tougher than the normal solvent based one but all are a lot more resistant to damage than normal lacquers), that's what the latin machetes come with and it's basically non removable without using solvents or a grinder....
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Post by bwaze on Sept 3, 2024 9:49:29 GMT
Yeah, Ballistol can gum up a bit if it collects, but it's easily removable, it doesn't dry hard. Hardwax and other drying oils, varnishes, lacquers are much more problematic in this regard. I once coated two polished helmets with some hard drying oil, after a few months it started to yellow really ugly (might have been dirt sticking to it, not actually yellowing). Fortunately it went off with the acetone, wasn't looking forward to removing it with abrasion.
Fluid Film is stable in wet conditions, and is even used as rust inhibitor on oli rigs and other salt water exposed environments. But yeah, it's still just an oil film, not hard protection, and has to be reapplied after handling.
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mrstabby
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Post by mrstabby on Sept 3, 2024 10:05:29 GMT
The hardwax oil didn't yellow so far and it isn't sticky at all - I have covered a bit of a stainless steel tang and guard of a knife by accident about a year ago while redoing the grip scales.
Personally I only use petroleum jelly for the blades since it's cheap, sticks well (even surviving some cutting use), doesn't dry and barely has a smell. But I use wax for carbon steel pommels and guards since it doesn't make them slick when handling.
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Post by eastman on Sept 4, 2024 0:49:21 GMT
If you aren't going to cut with it, then go with lacquer. I have a DelTin which has been protected by the factory lacquer for 35+ years.
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mrstabby
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Post by mrstabby on Sept 10, 2024 10:32:01 GMT
Yeah, Ballistol can gum up a bit if it collects, but it's easily removable, it doesn't dry hard. Hardwax and other drying oils, varnishes, lacquers are much more problematic in this regard. I once coated two polished helmets with some hard drying oil, after a few months it started to yellow really ugly (might have been dirt sticking to it, not actually yellowing). Fortunately it went off with the acetone, wasn't looking forward to removing it with abrasion. Fluid Film is stable in wet conditions, and is even used as rust inhibitor on oli rigs and other salt water exposed environments. But yeah, it's still just an oil film, not hard protection, and has to be reapplied after handling. Just thought I'd follow up. I have been testing out waxes and there are definately some that would collect a lot of dirt over time since they are a bit sticky especially when it gets hot.
I am impressed by the hardwax oil though, it feels at least as abrasion resistant as RenWax but also leaves a bit more of a visible layer, less visible than lacquer more visible than RenWax. I am pretty sure I could do better with more experience and better polishing.
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LeMal
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Post by LeMal on Sept 10, 2024 14:45:50 GMT
If you aren't going to cut with it, then go with lacquer. I have a DelTin which has been protected by the factory lacquer for 35+ years. Or spray shellac. Easily applied, easily removable.
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