Knife Maintenance

[grahamfoster]

I've got a couple of knives that need a bit of TLC and was wondering what the best way of restoring them to thier former glory was:

My dive knife is very blunt and is going to require a bit of work - I've got access to a grinding wheel...

My filleting knife is starting to loose its edge - what's the best way to keep it razor sharp? I will go out and buy a tool to keep it sharp but i don't know what the best one is (stone, file, electric gadget?).

Any advice will be much appreciated

 

[crusty]

Go the Stone
Get one if you can that is Double sided Course/Smooth they take a little bit of skill to use but once you get the hang of them you can get your knife razor sharp.
I have tried a few knife sharpening gadgets but allways go back to the stone
there is something medieval about them i love.


Crusty

 

[Huan]

My advice to you is either do as crusty says and get a good water stone and learn to use it, or take your knives to the local butcher and ask him if he could sharpen them for a small fee(maybe buy some sausages or something too).
For maintenance, I keep a thin layer of silicone grease on my dive knives especially where the blade meets the handle , this minimises corrosion.
DO NOT under any circumstances use a grinding wheel the use of a grinding wheel will probably necessitate the purchase of a new dive knife in rapid order. they remove material very fast and heat the blade ruining the temper.

 

[Amphibious]

listen to Huan and Crusty - they're on the right track, it's very easy to kill a good knife on a grinder.

Butchers can do wonders with beat up knives....

 

[grahamfoster]

Thanks for the tips guys - I'm gonna go get me some stone. I suppose a hardware store/diy shop will be the best place - unless anyone knows a specific source?

What's the technique for the best results? Do you fix the stone and move the knife over it or the other way round? I get on well with the local butcher so I might ask for a sharpening lesson next time I go in for BBQ supplies!

I won't go anywhere near a grinding wheel :duh

 

[SurfnSpear]

....more importantly you've obviously blunted your knife by cutting up too much fish! :ban rofl

 

[Alison]

Graham
Try this place for stones

 

[Fondueset]

For sure the stone. I also have a nice little wood block with a couple ceramic posts in it - this is very good for on-the-fly sharpening - particularly for the fillet knife - though most dive knives have soft steel and it is quite good for that. This is more for a quick tuning of the edge however - a course stone and a fine stone (some have two sides - one of each) is what you need to restore the edge. Grinder is only if you are completely rebuilding a thoroughly decimated edge - risky though.

 

[sickbugs]

grinders are bad, destroy the temper of the knife very fast, as mentioned earlier. even belt sanders will do that, so stay away from the high speed stuff.

if you just want them sharp, get a good stone, oil or water it doesnt matter, but dont use any honing oils, they will clog up any stone out there then you have all hell getting them clean, a stone will knock a decent edge onto a knife.

if your like me, and keep every blade within sight razor sharp (literally) then you need something better than a stone, and that something is sandpaper. 220 grit to shape the edge, 400 or 600 grit to get rid of all 220 scratches, then 2000 grit for the final polish, especially useful on fillet knives, aint nothing nicer than using a razor sharp fillet knife.

those handheld sharpening tools are bad too, they give you the wrong edge geometry, stay far from them.

as for sharpening, different strokes for different folks i guess, i like thin blades for filleting, i have one angle straight from the spine of the knife to the edge, this takes a lot longer to maintain than holding a knife at a few degrees from the stone/paper and giving it a slightly thicker edge, which is how i keep my diving knife. some smiths reccomend about 15 degree angle. even if you use a stone, i'd still use some 1000-2000 grit sandpaper after, it leaves the knife looking a lot better than if you just rubbed it against a rock

 

[grahamfoster]

Thanks guys and thanks for link Alison.

I'll get on the case and practice the proper technique - sounds like one of those knacks that when you get it right it 'feels' right. Even with the correct technique though my dive knife is going to take an awful lot of elbow grease!!!

 

[sickbugs]

the technique definately needs practice, ive been a knife fanatic since i was 4 and only a few years back when i actually started making them did i understand how to properly sharpen them, point of interest, to tell when your knife is sharpened properly, point it at a light and look down the edge at a slight angle, if you see any silver spots on it, they are dull spots, resharpen the entire edge to get rid of them, if you just sharpen the dull spot, you will end up with a slight concave (cant think of a better word) on the edge, and the next time you sharpen the knife this point will not be sharpened along with the rest of the edge.

 

[Mr. X]

Re: Knife Maintenance -- quick methods

grinders are bad, destroy the temper of the knife very fast, as mentioned earlier. even belt sanders will do that, so stay away from the high speed stuff.
.... i'd still use some 1000-2000 grit sandpaper after, it leaves the knife looking a lot better than if you just rubbed it against a rock

Sickbugs seems to have covered the pukka way to sharpen a knife (I always wondered -- so thanks for that). However, if you have a $10 dive knife off ebay and/or are in hurry (i.e. closer to the "rubbing it with a rock" end of the spectrum), you might want to consider using a small mill bast*rd file. This is standard procedure for maintaining ice axes. It will create a sharp edge very quickly, with no heat tempering issues, even on a blunt, flat tip dive knife -- in seconds. For ice axes & dive knives, you usually don't want a thin razor sharp blade -- it is better to have a slightly wider, stronger edge angle to stop the edge folding or bending.
Downside: it is easy to slip the file & scratch the knife (the cosmetic appearance of my dive knife does not concern me) and you might remove too much metal off a small knife (not an issue with my current dive knives).

I have 3 stones too. I found the two finer ones too slow for me & the 3rd coarse one performed well but not as well as the previously mentioned MBF and it cause more scratches.

I have used 3 different, inexpensive kitchen sharpeners that worked surprisingly well. The edge produced won't be a fine long lasting edge like Sickbugs of course -- but enough to cut up some veg. - or fish. I tried using one of the traditional carving irons but it did not seem to do anything for me -- perhaps you have to be a butcher. We had one kitchen knife with a sharpener built into the sheath, so that it was sharpened each time the knife was drawn - great idea.

 

[FLRick]

The trick to useing a stone is to keep the blade at a consistant angle to the stone. This is very difficult, & a skill I have not been able to master.

There is a stone sharpining system manufactured by "lansky" its sold at Sports Authority. It consists of a alum. braket that clamps on the blade & some stones that slide in the braket this holds the blade at an exact angle & makes it very easy to get a sharp blade. you will be amazed at how sharp you can get any knife to be. Try it you will not be disappointed.

 

[Spaniard]

http://www.heinnie.com/cgi-bin/heinnie_store/web_store.cgi?page=lansky/fr-lansky.htm&cart_id=

If you are in UK you can buy the Lansky system from the above link. I've not tried it myself but it got rave reviews from some hunting (shooting) friends so I might go for it......

 

[Amphibious]

I work every spring and fall as a Professional Hunting Guide, my knives go through quite a few large animals in a short amount of time. it's very important I keep a sharp knife/knives. the Lansky kit is what i use and have NOTHING but GREAT things to say about it. well worth the investment.

 

[dave]

Another vote for the Lansky
cheers
dave
www.spearo.co.uk

 

[Mr. X]

Another vote for the Lansky...
www.spearo.co.uk

Are you guys all going for the 40 GBP Lansky Deluxe Knife Sharpening System or the 4 GBP Lansky Mini Crock Stick Knife Sharpener? (Seems like ought to be some options between those 2 extremes).

 

[Alison]

Colin uses a Tormek elactric wetstone and Japanese waterstone to sharpen our knives but he had that gear for his work so not really a viable option he says but take a look in Machine mart they apparently have some cheap sharpening systems

 

[dave]

lansky standard kit (£30) for refinishing a blunt edge, pocket crock stick for quick touch ups
cheers
dave
www.spearo.co.uk

 

[FLRick]

I think I am using the standard kit. It came w/ 3 stones coarse, med & fine, 3 rods, bracket, & oil.