Knife sharpening

[camillio]

Last week I bought a new knife - Technisub Mini Zak Alfa. It arrived perfectly greased, but TOTALLY dull, making it practically useless. My question is: how sharp do you prefer your dive knives? I sharpen my kitchen knives until they shave my hairs. Is the same preferred here?

Sorry if the question is dumb, I'm a newbie in this field.

 

[foxfish]

I keep mine razor sharp, if you have a knife then it makes sense to keep it sharp
If you ever need it to cut rope or a net you want to do it fast.

 

[Pinniped72]

Definitely as sharp as possible, same for any serrated sections to the blade.

 

[camillio]

Thank you guys, that's what I originally thought. It's a big shame of Aqualung that it sells sharpen-it-yourself dive knives. I'm going to make it a razor

 

[Mr. X]

I have read a case made for sharpening (e.g. with a coarse stone) but not refining the sharpened edge (e.g. with very fine stones or stropping). The idea being that the roughness of the sharpened edge act as micro-serrations that are better for cutting rope/net/....

I used to do that, however, these days I do the the same as Pinniped72 - don't neglect the serrations.

 

[Willieboy]

I use the convex method to sharpen all my knives. It is accomplished using various grades of sandpaper, a computer mouse pad, and a leather pad with some sharpening compound. Once sharp, it's easier to touch up your knives rather than bringing them back from dull.

You can look up convex sharpening on the net to see how it's done.

 

[Mr. X]

...It's a big shame of Aqualung that it sells sharpen-it-yourself dive knives. I'm going to make it a razor

I know what you mean, the initial sharpness of a knife is an important part of your first impression. However, sharpening a blade is an important (once essential, now neglected) life skill and you will need to sharpen you knives from time-to-time, so might as well just do it yourself. Although Chinese labour rates would suggest that might be the more cost-effective place to do the sharpening.

 

[Willieboy]

I know what you mean, the initial sharpness of a knife is an important part of your first impression. However, sharpening a blade is an important (once essential, now neglected) life skill and you will need to sharpen you knives from time-to-time, so might as well just do it yourself. Although Chinese labour rates would suggest that might be the more cost-effective place to do the sharpening.

I learned to do it myself because I didn't have a choice. There wasn't anybody with the skill to do it for me. I tried various gadgets they I bought online and the all worked to some extent, but I was never really satisfied until I learned the convex method I wrote about.

I have a considerable collection of really well-made knives and it's nice to be able to tune them up when necessary.

 

[camillio]

Mr. X - I do personally sharpen my knives until they easily shave my hairs. However, the dive knives are not designed for cooking, but for saving lives. Are we going to pressurize new fire extinguishers and solder new AEDs in the future? What if I loose my knife on travel? Buy a new one plus a sharpening steel, or simply do a suicide mission with the dull toy? (no offence, just philosophizing )

 

[Mr. X]

Hi camillio, yes I can see from your earlier posts that you know how to sharpen, I was making a general point. Good point, replacing equipment on a trip is real possibility.I carry a small diamond file (round on one side, flat on the other) that looks a bit like a pen in my dive box, so I am equipped for basic sharpening, if necessary.

Willieboy. I have several motorized sharpening & honing wheels, japanese waterstones, diamond plates, etc. but you know what, a £7 combination oilstone by the likes of Draper or Faithfull with a drop of baby oil works as well as anything and I actually find oilstones less messy than waterstones. That said, the waterstones work exceptionally well on stainless steel (e.g. kitchen knives, filleting knives & dive knives).

 

[Pinniped72]

I have three dive knives, a standard swimmers knife, a cressi super totem and a beast of a dive knive from Lalizas, which is a full tang, thick blade rescue type knife and every one needed sharpening when I bought them, it seems to go with the territory.