How do you sharpen big, thick, heavy, long bladed knives?

P

PFDR

Joined
Jan 16, 2010
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First post, and glad to be here. now to the question.

My lanksy works good for all of my folders, and several of my fixed blades however i plan to get some bigger blades in the near future, and since i like to "do it myself". i would like to know the best way to go about it. there is no way that some of these knives are gonna work in my lansky clamp system. for example, blades with big recurves, also blades that are around the 7-9" blades, 1/4 thick, 1.5-3 wide form spine to blade, and overall lenghts from 10-13.5"(Graymans more specifically).

is there a bench grinder, and or a dremel tool that would work for this. i have been looking and haven't found much. also is there anything(an attachment) that allows you to get exact angles or do you have to eye ball it? i am more of a precision guy, if there isn't an attachment is there some kinda jig that i can get and or make to get the angles that i want?

thanks in advance.
 
Welcom to BF.
I use a variety of sharpening methods. My suggestion for the blades you describe would be to look into using a belt sander. There are some with jigs, most seem to be an adaptation of using a Lansky clamp mounted somehow, but I think you would be better off learning to freehand... with a bit of practice you can get the precision you need. You can get belts in a variety of grits, and a leather belt to finish with. Some use the HF sander it's inexpensive and a good start.

Here's a couple of vidoes for examples

http://www.youtube.com/watch?v=TLjFjT4vYsM
http://www.youtube.com/watch?v=eREokC4MPM0

cbw
 
back in the day I once used my lanski to sharpen a 17" blade, I just had to divide the edge into 2 or 3 different sections. It worked, but I wouldn't recomend it.

I do all my blades free hand these days, it just takes practice and a bit of experimenting to get a good technique down. - if doing a reprofile I like to start out with a good 12" file to get the new angles started then I switch to DMT stones or to sandpaper (for a convexed edge) then finish on a strop.

There are some great machines, and guid systems like the ones already mentioned here, but IMHO free-hand sharpening is a graet skill to learn if you are into knives! :thumbup:
 
For my KA-BAR Kukri Machete I think it is just too big to try clamping in my DMT Aligner - so I took my course (blue) hone and put it into the holder and used that freehand on the blade. It worked pretty well actually.
 
I prefer to convex grind thicker blades with a belt sander. It isn't difficult to learn. It also seems to make the the thicker steels cut more like the thinner ones while still having the added heft behind the edge. I haven't found edge geometry to matter as much with thinner knives. For those, any of the previously mentioned methods should work fine. I would add to those methods the option of hollow grinding an edge with a wet grinder and finishing with paper wheels.
 
On my Desert Dogfather, I pretty much followed the factory bevel, which I almost never do. But in this case it seems to work well for the intended purpose of the blade. Just took it down from a XC to EF then buffed it off nicely on a 1 mic felt strop. It cuts like nobody's business. That being said, my next major purchase in knife tools is a belt sander (thinking about the Kalamazoo one) and once I get confident enough to stick a $200 hunk of steel to it, it'll get convexed. Along with about 4 other blades.
 
I use a 1x30 Harbor Freight belt sander. Cuts like a laser. Ill post a vid sooner or later of sharpening with a grinder.
 
zhangmaster12 said:
I use a 1x30 Harbor Freight belt sander. Cuts like a laser. Ill post a vid sooner or later of sharpening with a grinder.
Click to expand...

Hmmm, *googles* that is a pretty nicely priced knife sharpener - way cheaper than a sharpmaker or aligner. I might have to hunt around to see if there is anything similar at a good price locally.

Where would you get a leather belt for a sander like that? Are they commercially available or do you have to make one from a strip of leather?
 
You can use the Aligner/Clamp

Clamp the Aligner/Clamp twice on the lenght of the blade.
Divide the blade in to thirds
Place the aligner on each of the 1/3rd marks.
Sharpen
Then move it to the next 1/3rd
There will be overlap, but the equal distance will grind and sharpen at the same angle

Important:
Make sure the Aligner is the same distance from the spine to get the same angle grind
So mark with a Sharpie the first position of the Aligner /Clamp and then mark again that distance

I did this on a 1095 7" Kabar
 
Gadgetaholic said:
Hmmm, *googles* that is a pretty nicely priced knife sharpener - way cheaper than a sharpmaker or aligner. I might have to hunt around to see if there is anything similar at a good price locally.

Where would you get a leather belt for a sander like that? Are they commercially available or do you have to make one from a strip of leather?
Click to expand...

Leather belt and micron belts available from a variety of places. LeeValley (leather) has some, Pop's Knife supply, Jantz, Econabrasive (Leather).

I like to use green rouge on the leather belt.

Seriously, this is the best way to sharpen big blades. It takes very little time, and gets your knives very sharp. Not quite hair-whittling (some daimond spray and hand stropping can fix that), but it'll lazer through newspaper, shave with the best of them, and ect.

edit: at least I cant get them hair whittling on the best sander. Maybe some people can, I'mt not be the best sharpener.
 
zhangmaster12 said:
Leather belt and micron belts available from a variety of places. LeeValley (leather) has some, Pop's Knife supply, Jantz, Econabrasive (Leather).

I like to use green rouge on the leather belt.

Seriously, this is the best way to sharpen big blades. It takes very little time, and gets your knives very sharp. Not quite hair-whittling (some daimond spray and hand stropping can fix that), but it'll lazer through newspaper, shave with the best of them, and ect.

edit: at least I cant get them hair whittling on the best sander. Maybe some people can, I'mt not be the best sharpener.
Click to expand...

It should be easier to get hair whittling edges on a Belt Sander than some methods. Sounds like you just need better belts and a tighter/looser tension on that belt.
 
These were all convexed, sharpened, and polished down to CrO2 on leather belts using a belt sander.

1242570065-IMG_0380.JPG


They are also nice for doing a little work on the handles too.

Gary
 
+1 for belt sander to grind your blades. For hand process the EdgePro seems to get the most recommendations for the big blades.

Do not attempt a standard bench grinder or dremel tool. That is called learning the hard way. Especially if you burn the temper out of your favorite knife.
 
Been getting along quite well with a belt grinder, wet/dry sandaper, and ceramic rods setup myself. as a khuk lover, the ability to sharpen large, thick blades with a recurved portion is a prerequisite.
 
I really need to get a belt sander ! the one being used in the 2nd youtube video in post #2 by cbwx34 looks great. i would like to know what it is and who sells them. if you have a sander that you think is just as good or better, i'd like the info on that too.
thanks, eh. roland
 
Same here-I am looking at belt sanders but not HF. How about it guys ? Which ones ? I think most guys are getting belts from Lees Valley ? Thanks
 
ordawg1 said:
I think most guys are getting belts from Lees Valley ? Thanks
Click to expand...

Yep, that's where I order mine. They've got ones specialized for sharpening. The ones around 300 grit or so seem to see the most use for me. Not too rough, and not too slow for touching up dull blades or minor reprofiling on big ones. I've got finer grits, but for the most part I can't be bothered changing the belt and after the 300 grit, I usually just switch to using wet/dry sandpaper and ceramic stones by hand to finish the job.

Been getting by with a cheapo $60 grinder quite nicely for the last few years myself. No complaints. :thumbup:
 
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