Dive Knife

[RiverWatchForge]

New to the site here. I've looked around the site and used google with no luck on an answer.

I spend quite a bit of time free diving during the summer and am on the ocean water in general quite a bit. I am wanting to make a few dive knives for myself and some friends that aren't prone to rusting. So my question is what can I make my knives out of/ finish them with to make them less prone to rusting?

Thanks.

[MastaStan]

If you make a knife from carbon steel, you are going to have to look after it well esp if using in water......cleaning, drying and oiling your knife will help keep it maintained.

If you want an easier knife to maintain opt for stainless steel and out source the heat treatment if you can't do it yourself. Saying this, no steel is 100% rust proof! You still need to look after it, albeit not as stringently.

Also I would suggest a plastic handle, most woods wouldn't cope with the repeated water exposure.

Hope this helps a bit.

There are wipes (I forget the brand) that put a protective film on knives for storage.

[Will W.]

I think Stan pretty much covered it. Stainless steel with a synthetic handle. 440c, 154cm, nitro-v, and cpm s90v come to mind as good blade steels.

For a handle, you may be able to use micarta, but im not sure how salt water would affect it, so i would recommend acrylic.

Stainless steel pins and hardware would also be advisable, i would go with a 303 series stainless for them, but ive heard 416 has comparable corrosion resistance if heat treated. 

I am not sure how epoxy is affected by salt water and if some are better than others. Worth looking into. 

[BIGGUNDOCTOR]

Depends what you would e cutting with it, but some use titanium for dive knives - light, rust proof, extremely tough. Won't hold an edge like a steel knife, but it depends on what you are looking to cut with it--kelp? Sharks?

[Joël Mercier]

Zknives database has interesting info on H1 steel. Spyderco uses it for their diving knives. According to them, it has the best corrosion resistance. From my understanding, it has to be work hardened to obtain useful hardness. 

It's a shame H1 isn't made available.

[ThomasPowers]

Second on Titanium, especially the alloys for a bit more hardness.  No magnetic signature either---just in case you run into any WWII stuff...

[MastaStan]

I was thinking titanium....but is it easy to work with?

[JME1149]

When it is at the correct temperature, titanium moves very easy. Problem is, it doesn't stay at the correct temperature for very long. 

[MastaStan]

1 hour ago, JME1149 said:

When it is at the correct temperature, titanium moves very easy. Problem is, it doesn't stay at the correct temperature for very long. 

How about stock removal...I'm thinking about beginners trying a titanium knife?

[Daninghram]

I know nothing about titanium but a good dive knife should be able to cut wire, rope, anything a diver could get wrapped up in. The knife should match the type of diving, Sport, wreck, Salvage. Good wire cutters on a lanyard make a more useful tool most times.

[HammerMonkey]

About 30 years ago I was diving in Puget Sound, just off the north side of San Juan Island. I came across another diver hopelessly entangled in a huge gill net that was wrapped around a huge rocky outcrop. he was in full blown panic and had consumed almost all of his air by the time I came along. I never found out if he had a dive partner that left him behind for some reason, or if he was just diving alone. My dive knife was always kept razor sharp and I was able to cut him free pretty quickly. It was lucky that I came along when I did.

I've tried to cut net out of the wheel (prop) of fishing boats with serrated, not very sharp  knives and found that nearly impossible to do. Titanium sounds cool, but if it couldn't hold an edge, I would probably pass as you never know when you will need a sharp blade.

[SLAG]

Mr. McGrady,

I have found that a good quality pair of robust kitchen shears works way better than a dive knife or k-Bar knife. That is when breaching netting of fish net entanglements.

The disarticulating(come apart),  shears are the most useful of that genre.

The lever action of the shearing blades of those shears is vastly more effective.

A good quality pair of kitchen shears usually ha plastic handles and the blades readily come apart (disarticulate), for cleaning or wiping dry. It does not matter that the blades are stainless steel. (i.e. extra rust resistant).  

They are not bulky nor get in the way.

Also, their lever action compensates for slightly 'blunt' blades.

It worked for us:   and I am certain that it will work for you, and all the other i.f.i. citizens.

Regards to all the gang.

SLAG.

[HammerMonkey]

Thank you Slag. I'd say that my days of underwater exploring are largely behind me. And it is even more unlikely that I will have the opportunity to rescue anyone again from a sunken fish net entanglement.

But it is good to know the scissor trick if, for some reason, it does come up.

[Charles R. Stevens]

The theory behind trauma shears, their Master Slag

 

But I don’t think you will be prying an abalone off the real with a pair of scissors.

[SLAG]

Charles,

Many thanks for your input.

Yes trauma shears will work very well. The single extended arm (one of the shear's arms) increases the leverage wonderfully.

And the blunt end saves cutting skin.

Those deceptive shears look surprisingly flimsy. But they are NOT.

They can cut through a U.S. cent!

We used similar devices for often heavier tasks hence the resort to more robust tools.

But Mr. Stevens is correct. Trauma shears will suffice for most uses, in the field.

Many thanks, Senior Stevens.

SLAG.

May I suggest an oyster knife for prying said abalone off the rock. But a K-Bar should also work.

[HammerMonkey]

The blunt tipped dive knife worked very well for prying them off the rocks...If there is anywhere that still has any decent size abalone that you are allowed to harvest! Used to be a good amount of nice ones up here in Puget Sound, but over harvesting decimated them. now they are tiny and limits are just as small.

 

[RiverWatchForge]

Thanks for all the input. I'll look further into it with what you guys gave me.

[Daninghram]

They make trauma shears for diving. google dive rite trauma shears.

[Will W.]

If your going to go with titanium, get yourself some nice dark glasses, like the kind used when plasma cutting, #4 shade if my memory serves me. The sparks that titanium throws off when grinding are extremely bright white, nothing like the orange/yellow sparks of steel.