Dull diving knife?

[Damselfish]

If you get a dive knife that is not sharp, it sounds like a manufacturing/QC screw up to me and I'd return or exchange it. A knife shouldn't be unsharpened when you buy it, unless maybe they advertise it that way for some special reason. If never heard of knives being sold unsharpened for legal reasons, sounds like an urban myth.

People are going to expect knives to be sharpened and I don't think a manufacturer is going to expect the average person to have the tools or knowledge to sharpen a knife properly, especially if it's pretty much an initial sharpening rather than something like honing your already basically sharp knife.

 

[rdolmat]

I agree! This puppy's goin' back today!

 

[pasley]

Back in 2001 when I bought my knife, it too was dull. I took it to a sharpening place and for a very reasonable fee it is now very sharp. In 300 dives I have never used it. I also carry shears, cuts line with one hand (a knife requires two, one for tension, one for the knife), which I have also never used. But it is safety equipment, you may never need it, but if you do you will really need it.

After every dive I completely disassemble my knife and soak it in fresh water, dry it and spray it down with silicone spray. 300 salt water dives later and it still looks brand new. I can't say the same for my dive buddy, his dive knife is all kinds of rusty from lack of proper maintenance.

 

[HenrikBP]

I spoke to an SP rep at BTS a couple of years ago when their new Mako knife was announced (nice knife btw.). He said that they are not allowed to sell knives that have both edges sharpened. So they were to sell the knife with the serrated edge sharp (much more difficult to do yourself), and leave the other edge (the back if you will) tapered but not sharpened. Could be something like that going on.

As for maintenance ... my inexpensive knife got quite rusty during a trip - lack of rinsing no doubt (so-called valet diving ...). I put it in a Coke bath for a week and the rust wiped right off. Other than a few minor surface pits, the knife is like new, and probably more rust proof than when I bought it.

Henrik

 

[ScubaSteve]

.......I put it in a Coke bath for a week and .....

.....now it tastes great with Rye and Lime

 

[bottomfeeder22]

Know what else is really rust-proof? Titanium! Put it away wet, doesn't matter. I'll never buy another SS knife again.

 

[sglake]

I'd take it back and check the new one before you left! More people get hurt or have problems with a dull knife than a sharp one!

 

[mudhole]

Hi folks!
newbie diver here...just getting my 'kit' together.
I bought a dive knife today (brand new) and when I brought it home, the non-serrated side of the blade is as dull as a cotton swab. Is that normal? perhaps a safety issue? Or should it be razor sharp? (ie: the safest knife is a sharp knife?): pirate5: cheers rich

You seem to have the right idea about knives. . . they are tools to solve those problems a knife can solve. Diving knives are sometimes fashion items and not tools. There are diving knives made out of many materials. Most knives have an iron base blended with carbon then mixed with other metals to give them some resistance to rust. There are mixtures that include nickle, (300 series steel) reduces rust, and cannot hold a sharp edge, because nickle is a soft additive. (400 series steel) is a mixture of iron, carbon and chromium. . . these are the most popular knife steels. A little care will keep these rust free. Titanium is a new knife material, Titanium is soft and won't hold a sharp edge, so knifemakers coat the core with Titanium nitride which does hold an edge. They are expensive, and should not be resharpened too often.

A knife is a tool. . . and good tools are safer to use.

When shopping for a knife, consider only those makers that identify the steel. Many of the diving companies buy their "branded" knife from someone else, and more are cheap steel than good steel. Knives I have experience with and respect are Kershaw, Riffe, and Scubapro. There are others that I haven't tried, but they should identify what steel they use. Good quality knife steel, should be sharp in the box. . . and should stay sharp for years. Poor quality steel will usually be dull in the box, and when sharpened will go dull, just sitting in the box.

Some divers choose EMT shears. . . They have some advantages with some cutting jobs, and disadvantages with others. Not all EMT shears are the same. Again, choice of steels makes some good, some junk. I was an EMT and Have found a few good ones, I kept, and some junk which I threw away. . . check out the Pivot pin, a weak point for cheap shears.

 

[Spearo]

Some knifes are just like that! Maybe you bough a clam/oyster knife, I never seen one sharp.
If the tip is pointy then the knife should be more or less sharp or you make it sharp but if it is flat/blont tip they're not sharp at all.

Will your knife "hold the edge"? The El Cheapo types do not!

 

[rdolmat]

Some knifes are just like that! Maybe you bough a clam/oyster knife, I never seen one sharp.
If the tip is pointy then the knife should be more or less sharp or you make it sharp but if it is flat/blont tip they're not sharp at all.

Will your knife "hold the edge"? The El Cheapo types do not!

Ah! yes...it's a blunty tip! The serrated edge is sharp, but the other edge is dull...in fact, half the people I talked to lately (at the LDS, online etc) say it's normal...

oh well, if I need to cut, I'll use the serrated edge..if I need to scrape, pry I'll use the other edge.

I prefer to not pull the knife out too quickly and chop my arm off!