remedy? rusting rescue knife

"…we’d all use carbon steel knives…"
Last year I asked people where I might find carbon steel knives, and expressed my belief that carbon-steel knives hold an edge better than stainless steel (that CONTINUES to be my experience, by the way), and that they can be sharpened to a finer, sharper edge in the first place. That was the longest discussion I’ve ever sparked on these boards, and I don’t think there was anyone here who agreed with me about carbon steel holding an edge better than stainless, though some conceded it was better for woodworking. Still, there are a lot of custom knife-makers using old metalworking files and junk car springs as material stock, and that tells me something about how those guys feel about carbon steel.

Never use steel wool
You should never use steel wool to clean rust from a stainless steel knife. Knife steel has tiny pores on the surface, and fragments of carbon steel from the steel wool will lodge in the pores and rust, causing the surrounding stainless steel to begin rusting. Use bronze wool, which can be found at most hardware stores in the furniture refinishing section. It will work best if you first treat the rust spots with a penetrating oil like WD40.

Question for Brian; appreciation for all
. . . ideas offered here by you guys. Lot I didn’t know anything about such as . . .

Bronze wool. Likewise TufCloth. Good to know both.

As for the rescue hook suggestion: yes, that would work great for me. One thing I like about my Bearclaw knife is that it’s so small – no larger than a rescue hook. Takes little room on my PFD and stays out of the way up high on the strap.

QUESTION FOR BRIAN: How do you wear the rescue hook? Is it easily grabbed off your PFD? I couldn’t tell based on the picture.

Folding knife versus fixed blade: I feel I can’t go with something that has to be removed from a pocket and opened in a tough situation such being entangled and upside down. I feel – and this is just me – that I need something to hand that is ready to use. I did, however, see a cool folding knife on the Diversdirect site where a rope-cutting hook on the back side of the blade stood proud of the sheath. Assume you could use the hook without opening the knife.

Re carbon steel knives, I love them and use them in my kitchen. When I’m not too lazy I can easily put an edge on them that will shave my arm dry. Great parlor trick. I don’t keep them that sharp, though.

Thanks, everyone! I learned a lot here. Right now I feel likely to keep working on my Bearclaw knife with bronze wool or tufcloth until I can’t stand it anymore or the serrations in the blade are rusted or I feel filthy rich. At which time I might buy a titanium Pilot Knife with blunt tip and rope-cutting hook. (And bottle cap lifter of course!)


edge schmedge
Reef is right. A rescue knife presumably only sees occasional use, so maintaining and edge shouldn’t be as important a factor.

Someone told me that titanium knives have carbide steel content. I’m not sure if this is true, and perhaps only true when it comes to cooking knives, a whole 'nother world.

I know cooks who won’t bother with newer, ultra hardened steel. They prefer the ease with which traditional stainless sharpens.

I wonder how long it’ll be before we see ceramic dive knives?

Was it a Comp?
“I did, however, see a cool folding knife on the Diversdirect site where a rope-cutting hook on the back side of the blade stood proud of the sheath. Assume you could use the hook without opening the knife.”

Was it a Comp in Titanium? I bought two of those, one for my paddling PFD, one for my diving BC.

Since I don’t do whitewater, paddle Galveston Bay and the Gulf of Mexico exclusively, I don’t need to deploy my knife immediately to extricate myself from a situation, but I do think with the comp you could use that ropecutting hook that is on the spine of the knife without having to open it up. Since the knife has a clip on the handle, you could have it clipped to your PFD, so it would be there to use.

Incidentally, I did use the titanium comp folder I keep in my PFD this weekend. I found an abandoned crab trap, its buoy line went down into the water, and I could not figure if it still had a buoy on it or not, but it seemed stuck under a geotube breakwater. Shredded fabric from the geotube was tangled up in the chicken wire of the trap, so I had to use my knife to cut through the shredded fabric, and also to cut the buoy line. It cut through just fine, even though I don’t think I have ever sharpened the thing - titanium works when you need it to. I pulled the trap up on top of the geotube breakwater so a park ranger would see it and dispose of it (I was at the edge of Galveston Island State Park) since I couldn’t haul the thing back on my kayak. Was able to free a juvenile flounder that had gotten trapped inside.

I want them instead actually. it’s on
my list.

Yes, a Comp I think
The titanium folding knife had “Armor” on the handle but the identical looking one in steel said “Comp” on the handle.

Glad you found a use for yours, RM. I’ve cut through fishing line tangles and hanging lines with fishhooks with my Bearclaw and odd strings hanging off my own or others’ paddling clothes – but never to free myself from entanglement. Better to have it and not need it . . . . Mine rides conveniently far out of the way.


Titanium Knife
Ti6Al4V blade. End of issue. Ask any Navy SEAL…or commercial diver.

Wrong steel
Benchmade offers many of their knives in more than one type of steel. For salt water use, you need to order the “H2O” model of a given knife or rescue hook, as the X-15 steel is highly rust resistant. The standard stuff won’t hold up against salt water.

You can mount it on a lash tab…
…which is what I assume you’re doing with your current knife. That’s what I do (it’s attached with zip ties), though some people prefer to mount it to a shoulder strap. It depends on the layout of your PFD and your personal preferences.

It’s just as fast and easy to deploy as a sheath knife; you just grab it and yank it from the sheath.

IMO, a folding knife in a PFD pocket is nearly useless as a rescue tool. It takes way too much time and fumbling about to deploy it and depending on the nature of the situation, that could be critical. As with my radio, I want my cutting device mounted where I can easily and rapidly access it with one hand, either hand.

Yeh, i know that now…$ spent and
i am a little pissed that my paddle shop carries this style …i called them 1st and told them it rusted and questioning why they would sell this type of knife for people sea kayaking etc…a kid @ the shop told me about Tuf-Cloth but the owner knew nothing about it. Hmmm? Not happy with them and now am making the best of what i purchased.

I guess I don’t stand corrected >.>
“Titanium alloys do have a higher strength-to-weight ratio than virtually all other metals. While you would have to have thicker cross-section titanium knife to have the same strength as a steel knife, that titanium knife would still be considerably lighter than the thinner steel knife.”

At least you understand this point. But you’re missing part of the equation. All knives (apart from trainers), necessarily come to as thin (fine) an edge as possible. You can make a spine as thick as you like, but as I said, ultimately it’s not going to make a difference, as I said, when used for a knife. That’s not the weak link.

“If edge were the most important quality for a dive or paddling knife to have, we’d all use carbon steel knives, because they have far better edgeability than stainless. Corrosion-resistance is more critical than edge-retention, and stainless, while better than carbon, is still vastly inferior to titanium.”

I guess we’re just going to have to disagree here. Edge retention is absolutely important to me.

“Before I got a titanium dive knife, I would spray my ss Tusa (not a low-quality knife)”

I’m a diver too, with certs from nitrox to advanced wreck diver (TDI all the way). Tusa is crap. And trust me, you don’t go to a dive company for a good dive knife.

“If you want to stick with stainless and do the extra work to maintain a piece of equipment that doesn’t get used very much, I have no problem with that, but there is no need to disparage those who have come to appreciate the benefits of titanium.”

My dive knife isn’t stainless. It’s a hard chromed O1 tool steel knife by Kevin “Mad Dog” McClung. I have no problems with it.

I will reassert: The benefits are corrosion resistance and non-conductivity. First benefits the masses, second benefits people with very sensitive jobs.

Commercial divers?
Ti? I have met more than a few commercial divers, and without a doubt they are using steel like a Green River.

SEALs? Not so much. You’ll find more SEALs walking around with a Glock knife than any other single brand. Marketing folks care more about which knives the SEALs are carrying than the SEALs themselves.

Cutting through thick aramid rope is a big task for any knife, Ti just isn’t up to it.

I know use Ti on the job as it is not magnetic and is inert in salt water. Agree it doesn’t hold an edge as well, but it serves well enough to cut anything a kayaker needs! Commericial divers I know also like it for the reasons above but agree it needs regular edge work.

coke is it

About coke . . .
Beckt, are we sure it won’t dissolve the entire blade as well? :slight_smile: Remember when people used to dissolve chicken bones in Coke?



wow…good to know, i learn so much
from P.netters!

Let me get this straight -

– Last Updated: Aug-16-10 3:59 PM EST –

You have a knife made of O1 and you're claiming that edge-retention is "absolutely important" to you? Pfft. If you really want a steel that has edge retention, why don't you have a blade made out of A2? Sure, it's tougher to sharpen, but it keeps its edge a lot longer and is a little more corrosion resistant than O1. So why don't you have an A2 blade? Maybe because you're making some tradeoffs?

How many knives have you had break? I personally have never had a titanium knife break, I haven't talked to anyone who has had a titanium knife break, but I have broken the tips off steel knives or chipped the edge a handful of times in all the years I have used knives. I'm not saying this means titanium is better, just that knife breakage isn't very common, but when it does happen, it can happen to any knife material.

"I'm a diver too, with certs from nitrox to advanced wreck diver (TDI all the way)."
Wow, I'm so impressed. I only have my NAUI through Rescue, and I also have EANx, as well as S&R, Navigation, and Deep. We could flex certs and log books at each other some more, but I don't know what that has to do with knife material.

Tusa isn't crap, many of their models get top marks with Rodale's Scuba Diving's Scubalab and other gear raters. You're either trying to be a gear snob or hoping to score points with people who aren't familiar with dive equipment.

That Tusa wasn't my first dive knife, by the way. that would have been the surplus Navy Mark III. I suppose now you'll say the knife used by Navy Seals is crap. That knife did have two issues which were apropos to this discussion. The first, it was heavy as anything. I might as well have been diving with an acme brick attached to me. Another plus for titanium.

The second, it was AUS-8, with a black epoxy finish for corrosion resistance. Problem was, that finish got worn off in places where the knife contacted the sheath, as well as along the edge. That's a problem I have with relying on surface-coatings to keep knives from rusting - those coatings can wear off - they WILL wear off, HAVE to wear off along the edge, where you sharpen them. That leaves the edge vulnerable to rust and corrosion. Use of a knife edge isn't the only thing that is going to dull the edge - rust along the edge dulls it, too. It's often going to be the first place on the knife to get corrosion, even corrosion you can't see, but which dulls the edge, because of the edge getting worked so much. If you have ever seen a Scanning Electron Micrograph of a properly sharpened knife edge, you know that there are all sorts of tiny ridges and grooves that increase the surface area and make all sorts of nooks and crannies for oxidation to occur. So while your chromed finish keeps the very rustable O1 looking pretty, it isn't doing anything to protect the functional part of your knife - the edge.

So again, for knives for diving and for saltwater paddling, it's going to come down to corrosion-resistance. In this environment, even edge is about corrosion resistance.

You’ve never used a differentially heat treated O1 knife before. I have some A2 (and others) knives by custom makers, the O1 from Mad Dog wins.

You’re out of your depth here. Sorry if that sounds patronizing. But I have spent way too much time talking knives with people to even be motivated to “debate” steel vs. Ti, it’s that ridiculous.

And, Tusa is crap. They make a decent entry level mask, that’s it. It’s in dive stores everywhere because it’s higher margin massed produced Japanese gear made in pretty colours.

That’s okay
I’m feeling a little relieved that I am “out of [my] depth,” in your estimation. I think I should need to start worrying about myself if I found I was taking myself as seriously as you take yourself. Knives are just tools, as are you.