The Chairman
Chairman of the Board
I heartily agree with Joewr on the composite knives issue. I have have seen two where the owners have asked me how to re-affix the edge. I merely told them to sharpen the carbon base, and use that... :tease:
Knife Care
- Thread starter jimbo
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Grajan
Contributor
I have a Wenoka that I foolishly assumed would not rust so it is now in horrible condition - I will use a Dremel polisher to get it back.
For me a knife is a very rarely used emergency tool and I would dearly love it to be maintenance free - enough other stuff to do as it is. So how about dipping the whole blade in hot wax?
The wax will not interfere with cutting and should protect the blade the rest of the time. That way you should only need to clean/recoat it after you have used it (hopefully never).
Will this work?
For me a knife is a very rarely used emergency tool and I would dearly love it to be maintenance free - enough other stuff to do as it is. So how about dipping the whole blade in hot wax?
The wax will not interfere with cutting and should protect the blade the rest of the time. That way you should only need to clean/recoat it after you have used it (hopefully never).
Will this work?
FredT
Guest
420 SST is a good material that holds an edge well, but it will rust a bit, and that rust does stain the metal.
One method of cleaning is mechanical removal. This is relatively fast but takes elbow grease.
The easy way is to simply soak it in Phosphoric acid for a while. Coca Cola has a fair amount of Phosphoric in it. A couple hours in a non-metallic container of Coke will clean up most light rust on any stainlesss.
Rustproofing of old black powder guns used in wet environments was done with wax floating on a vat of boiling water. The boiling water heated the metal and caused rapid drying, the very thin hot wax coating applied as the metal was removed from the vat protected the metal until the next cleaning.
If you just have to do things the hard way the polish route works. I have other things to do besides polich metal so I use the chemical method.
FT
One method of cleaning is mechanical removal. This is relatively fast but takes elbow grease.
The easy way is to simply soak it in Phosphoric acid for a while. Coca Cola has a fair amount of Phosphoric in it. A couple hours in a non-metallic container of Coke will clean up most light rust on any stainlesss.
Rustproofing of old black powder guns used in wet environments was done with wax floating on a vat of boiling water. The boiling water heated the metal and caused rapid drying, the very thin hot wax coating applied as the metal was removed from the vat protected the metal until the next cleaning.
If you just have to do things the hard way the polish route works. I have other things to do besides polich metal so I use the chemical method.
FT
Grajan
Contributor
I like the chemical approach. coke sounds good (if a little worrying - I tend not to routinely drink metal cleaners....).
I really like the hot waxing method - much more efficient than a bowl of wax. I will try it and let you know how it goes.
I really like the hot waxing method - much more efficient than a bowl of wax. I will try it and let you know how it goes.
Green_Manelishi
Contributor
Regardless of the cleaning method, alloy used, sheath
material, etc. it is NOT a good idea to store a knife in a sheath.
CARRY the knife in a sheath (or your hand)
STORE the knife on a shelf or somewhere OTHER than inside
the sheath.
material, etc. it is NOT a good idea to store a knife in a sheath.
CARRY the knife in a sheath (or your hand)
STORE the knife on a shelf or somewhere OTHER than inside
the sheath.
A good set of 4 steakknives is about $4.00 at the dollar store. When they get too funky, toss away. My "good" knife has been on the shelf for two years. Gotta put it on Ebay one of these days.
Stainless steel does not rust. It gets surface stains from free iron on the surface, if this condition continues, due to repeated exposure to salt water, it can pit the surface.
Stainless comes in three broad categories - -
300 Stainless - - 303, 304, 316 are the most common. Some older forms are called 18-8. This is what the flatware in your kitchen cabinet is made out of. Great corrosion resistance because of the amount of nickel and chromium, but it wont take a sharp edge to save its life. 320 is the most salt resistant of the lot, mostly used for lab hardware and pipes.
400 Stainless - - Hardenable stainless. Not case hardened, but full hard the whole way through (at least in something as thin as a dive knife). This will hold an edge, but not the sort of razor sharp edge we would expect. These grades are very prone to 'corrosion' and 'staining' especially when near salt water.
Precipitation Hardening Stainless - - things like 17-4PH and the like. Full hard the whole way through. Corrosion resistance like the 300 series. A little pricey for dive knives, if anyone has seen one let me know.
FredT was on the right track with the Coke trick. Stainless won't rust, but if there is any 'free' iron left on the surface that is where your staining comes from. The Acid eats away the iron and leaves behind a layer of chrome or nickel oxide. I normally use a 1:5 mixture of white vinegar and water. I have to try coke. What you are doing is called 'passivation'. There is a diferent 'pickling' mixture for every grade of stainless, do a google search but most of the mixtures will be hell on earth to brew up at home. Stick with Coke or vinegar.
You need to do this when you pull the knife out of the package, and then after every couple of dives. After you let it soak for ~30 minutes, rinse it thoroughly. Don't worry about the acid eating the knife, once the free iron is removed the process stops itself. You then want to coat the surface with silicone gel or jelly, this is your added insurance. You also need to be very diligent about rinsing your knife after every dive!!
You should also acid soak the knife after it is sharpened. It can pick up iron from the last thing you sharpened. Try not to take a wire wheel or grinding stone to your knife becuase you run the risk of really coating it with free iron (and it will stain in a heartbeat). If it has started to pit a Dremel with a cloth wheel and a little rubbing compound should bring back the shine, be prepared to invest an hour.
Be especially careful anywhere there is metal to metal contact on the knife (i.e. hilt to handguard). Even if they are the same grade of stainless there is slight diferences in the exact composition. When dissimilar metals touch underwater they are prone to galvanic corrosion, which is a form of rusting. Look for a stainless knife that is just a metal blade with a plastic handle and nothing else, this will eliminate this problem.
The long and short, if you want a pretty dive knife, mount it above the mantle when you pull it out of the box. If you want a workable stainless knife, be prepared for maintenance after every dive. Are you thinking that the $70 for a titanium knife isn't that much now???
Stainless comes in three broad categories - -
300 Stainless - - 303, 304, 316 are the most common. Some older forms are called 18-8. This is what the flatware in your kitchen cabinet is made out of. Great corrosion resistance because of the amount of nickel and chromium, but it wont take a sharp edge to save its life. 320 is the most salt resistant of the lot, mostly used for lab hardware and pipes.
400 Stainless - - Hardenable stainless. Not case hardened, but full hard the whole way through (at least in something as thin as a dive knife). This will hold an edge, but not the sort of razor sharp edge we would expect. These grades are very prone to 'corrosion' and 'staining' especially when near salt water.
Precipitation Hardening Stainless - - things like 17-4PH and the like. Full hard the whole way through. Corrosion resistance like the 300 series. A little pricey for dive knives, if anyone has seen one let me know.
FredT was on the right track with the Coke trick. Stainless won't rust, but if there is any 'free' iron left on the surface that is where your staining comes from. The Acid eats away the iron and leaves behind a layer of chrome or nickel oxide. I normally use a 1:5 mixture of white vinegar and water. I have to try coke. What you are doing is called 'passivation'. There is a diferent 'pickling' mixture for every grade of stainless, do a google search but most of the mixtures will be hell on earth to brew up at home. Stick with Coke or vinegar.
You need to do this when you pull the knife out of the package, and then after every couple of dives. After you let it soak for ~30 minutes, rinse it thoroughly. Don't worry about the acid eating the knife, once the free iron is removed the process stops itself. You then want to coat the surface with silicone gel or jelly, this is your added insurance. You also need to be very diligent about rinsing your knife after every dive!!
You should also acid soak the knife after it is sharpened. It can pick up iron from the last thing you sharpened. Try not to take a wire wheel or grinding stone to your knife becuase you run the risk of really coating it with free iron (and it will stain in a heartbeat). If it has started to pit a Dremel with a cloth wheel and a little rubbing compound should bring back the shine, be prepared to invest an hour.
Be especially careful anywhere there is metal to metal contact on the knife (i.e. hilt to handguard). Even if they are the same grade of stainless there is slight diferences in the exact composition. When dissimilar metals touch underwater they are prone to galvanic corrosion, which is a form of rusting. Look for a stainless knife that is just a metal blade with a plastic handle and nothing else, this will eliminate this problem.
The long and short, if you want a pretty dive knife, mount it above the mantle when you pull it out of the box. If you want a workable stainless knife, be prepared for maintenance after every dive. Are you thinking that the $70 for a titanium knife isn't that much now???
I've been a cutlery nut since I was a young boy. Have always believed that a knife should be able to CUT to be worth carrying.
One of the best aspects of diving is the opportunity to buy a new type of kinfe!
Ever since I was able to master the craft well enough to do it, I've tried to keep at least one blade of my pocketknife sharp enough to shave with.
Some great info has been shared here. Thanks.
I'll have to try the Coke/vinegar trick on some Leatherman pliers that picked up some rust stains.
KYDan
One of the best aspects of diving is the opportunity to buy a new type of kinfe!
Ever since I was able to master the craft well enough to do it, I've tried to keep at least one blade of my pocketknife sharp enough to shave with.
Some great info has been shared here. Thanks.
I'll have to try the Coke/vinegar trick on some Leatherman pliers that picked up some rust stains.
KYDan
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