Rusted after FIRST dive!!!

[jplacson]

I have a Bluetang and it did rust as well... but then, I opted for the 412SS instead of the 316SS. It rusted bad... I just used a rock to scrape off the rust... it actually doesn't rust more than it initially does. Soaking it in Coke is supposed to work, but I haven't tried that yet. Wiping it with WD-40 or the famous TV product "Dura-shine" works well to prevent rust.

 

[TRit21]

Most knives that stay sharp are made of a 400 series alloy steel. That is the same alloy that high grade pocket knives are made of. The reason for this is that is retains a sharp edge very long and will cut for a long time without losing this edge. Some knives are made of 300 series alloy steel which will not hold an edge long (softer,easier to machine) but is more resistant to rusting. So it is a trade off, sharp for a long time or no rusting. If you clean the knife after every dive I would opt for the 400 series, if you don't like doing maintenance then go with the 300 series. Titanium is nice because it does not rust but is expensive and also is not made to hold an edge for a long time. The harder the metal, titanium, the more likely to chip also.

 

[Tom Winters]

Bummer about the Blue Tang rusting - try to take it back for a Remora. I don't understand it - but the Remora just does not rust up on me. And it's waaaaaaaay cheaper than even the cheapest titanium knife.

 

[simbrooks]

Hydroalloy is claimed as a SS that has the sharpness of 416, but the corrosion resistance of 316 - according to UK. I have the fusilier and it hasnt rusted so far in a few salt dives - including being left in the car and gear box unwashed for many hours of driving home.

 

[IceBergSlim]

I don't think EMT (Emergency Medical Technician) shears are designed for contact with water - they're designed for contact with blood, bone, denim, skin, etc. So for the primary purpose of EMT shears, the fact that the pin isn't SS isn't a big deal. That's why.


Thanks!
Next time I do a "bone dive" I will keep that in mind! (I am only jivin, I understand your thought.)
Thanks for the info, Dg

 

[velazques25]

Technically speaking (I have a degree in chemistry) stainless steal doesn’t rust is the impurities in the forging process. The main culprit is carbon that is added to the iron alloy to give it tensile strength. SS is a very hard material but is has a very low tensile strength and will brake or split very easily if the carbon content is low. There are 2 basic alloys of SS in the scuba equipment in the market is 420C and 320C SS. The 420 has excellent edge retention capability ( harder to dull but harder to sharpen) it’ takes longer to rust but it is a little more brittle(sharp point brake off easily). The 320 allow is a softer alloy that is a lot easier to sharpen is not as brittle as the 420 and basically cheaper to manufacture so you will find it in cheap gear and some name brands with fancy names and it will rust more easily.
Titanium has the advantage of having“no rust” or “0” maintenance capability. The bad news on this material is that is very hard material that doesn’t maintain a sharp edge very easily and you will need to use a special diamond hone to sharpen it and after that you have to used a special technique to do it.
Personally I own a 420 scuba max BC knife (that had some pitting in the first dive) that works great every 10-15 dive I disassemble it and clean it thoroughly with clean water a little soap, then I polish it with aluminum or magnesium metal polish paste (the kind use to polish car rims) and the use a little Teflon lubricant grease, it is better that silicone grease because it doesn’t washes away very easily then after every dive I clean it with fresh water and rinse it’s holster. I also own a Larry Ramey titanium knife that will a lot of work with the bench stone and good quantity of patience I have been able to give a nice edge that is capable of cutting open a can of beans a still remain sharp. Not an easy way to with a titanium knife.

More on knives: http://www.ameritech.net/users/knives/index.htm

 

[velazques25]

The pin on the EMT Shears is maned of heat treated steel with high carbon content for durability. I will rust very easily in salt water. It was never intended salt water used. I recommend to by shears that where made with a salt water environment in mind like sport fishing shears or scuba shears sold my TRIDENT scuba equimp. co

 

[Firediver]

Coat in petroleum jelly before each dive and when storing... works for both my knifes.. both are 420 SS

 

[jonnythan]

I've had a 415 Blue Tang since my first dive. It's only been on maybe 30 or 35 dives, but it's spent a lot of time sitting in the bin in my trunk soaking wet, and I don't have any rust on it yet. I think it's strange. Salt water dive?

 

[bebo]

I've done several more dives with it. After I cleaned it w/ a metal polisher, the rust hasn't come back. After every dive I disassemble it, wash it, and give it a good spray w/ 4WD. I guess a couple of "rust appearings" might be on the way, but so far, so good.
I also give a good spray to the sheath.