Sharpening

Yes, but the leading edge being the leading edge would experience greater friction, would it not? And being thinner than the rest of the blade would take less friction to spike up into the range where damage to the temper can be done.

This is all just conjecture on my part. I know enough to keep my blade cool while sharpening, but beyond that I'm an amateur metallurgist at best.
 
It may well depend on the type of media you are cutting, with or across grain etc. I would think the shoulders would get hottest if anything though, but then during the upstroke and swing of the chop it's cooling off again... I don't know! Does anyone here own an IR camera? My uncle actually does, (he's a commercial building inspector) but I don't actually have anything that really falls into the chopper category... :( :o :( :confused:
 
I usually get it nice and sharp with the belts, work down through a couple different grits, then hop to my DMT plates to clean up the cutting edge. I feel that I have much better control in the final product as I'm forced to go at a slower pace.

After this though, its a surgi sharp leather belt with 6, and then 3 micron diamond lapping compound.

I've never had less arm hair
 
SpyderPhreak said:
The Kalamazoo is a great machine, for SO many reasons, but at how many multiples in cost vs. the HF? Not dissing it in any way, but a lot more folks, myself included, have the much cheaper 3,400 RPM (!!!) HF instead. The HF has a ~4" drive wheel, so it moves those little 1x30 belts at about 40 MPH! :eek: What size is the drive wheel on the Kalamazoo?

You definitely have to be careful not to overheat the edge. IMO, the belt plays nearly as important a role in that as the machine's RPM does.
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Spyder, I hear you about the cost, and your point is well taken. Judging from your edge photos, you certainly have a practiced hand and handle the faster belt well. I do think the Kalamazoo or any slower belt will be more forgiving. Re belt type, obviously the coarser the belt, the more friction and heat. I will try to measure the wheel on the Kalamazoo and get back to you; I don't have that info in my brain ATM.
 
mach 5 said:
Spyder, I hear you about the cost, and your point is well taken. Judging from your edge photos, you certainly have a practiced hand and handle the faster belt well. I do think the Kalamazoo or any slower belt will be more forgiving. Re belt type, obviously the coarser the belt, the more friction and heat. I will try to measure the wheel on the Kalamazoo and get back to you; I don't have that info in my brain ATM.
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Thanks, and yes, the faster belt definitely takes practice. The Kalamazoo will certainly be more forgiving if the belt runs slower (and I'd bet it does). I'm just curious, as a 6" drive wheel at half the speed will still be 75% as fast as the HF. Re: the belt; I was more meaning that in a given grit size, certain types of belts will cut a lot cooler than others based on design and grit composition.
 
I use an Edgepro among other methods, I've had it around four years. It can be very precise and make beautiful mirror edges - but it takes time. And the stones that come with it do wear, and are not what I would consider cheap. I ended up buying the aluminum backers and gluing DMT plates on them so I didn't have to worry about my stones dishing. Also touching up an edge takes time if you didn't use one of the marked angles on the main pole, since you have to find it buy marking the edge and then seeing if you are grinding to the apex or not.

Yeah, I'm that lazy these days. Which means I need to buy paper wheels. Those things look fast.
 
The Harbor Freight 1X30 is an amazing tool but do be careful around them. The first thing I did with mine to make it usable was rip off all of the plastic guards on it. I use my Crapsman 2x42 for grinding metal and the HF for some tighter grinds, sharpening, and leather work.
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I dunno how fast that wheel was going when it flew past my head but it most definitely scared the snot out of me. Put a nice dent in my beer fridge in the garage also. It's such a useful tool though I didn't blink at getting another one. I have a bunch of belts, my leather belt from TruGrit with black BRKT compound is my favorite for finishing an edge.

The EdgePro and Wicked Edge get a lot of high marks, I went with the KME and I wouldn't dream of going to all of that hassle to just sharpen a knife but it is amazing at reprofiling a blade. Once it's got the edge I want I use DMT or more recently the WorkSharp guided sharpener to keep them in line.

This Safety Mutt had some work done by the KME.. I'm not saying it's exactly like a laser scalpel from hell.. but I'm also not saying it isn't.
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A lot of people send out but its definitely worth it to invest in a system. Its always good to learn about the degree you want for specific steels and uses. I think its fascinating and kinda relaxing. I use a Tormek T-3 because I carve and constantly need to sharpen but there are plenty of cheaper systems that do a nice job. stay away from anything electric though you want to stay in control, Tormek being the exception. Good luck with the search.
 
Thought I'd drop this here for anyone who hadn't seen it yet:

http://www.bladeforums.com/forums/s...f-an-edge-during-belt-sanding-initial-results

The OP is experimenting on power-grinding using the WSKO and temp-sensitive lacquers to indicate heat-level at the apex, with a deliberate effort to over-heat the edge. Bluntcut made some recommendations that he should implement - use hardened steel against finer-grit belts - but the initial results are interesting.

I then subjected the blade to aggressive grinding on the WSKO/BGA:

I used the coarsest belt.
I used the maximum belt speed.
I pressed the blade into the belt with much more force than I typically use.
I did not move the blade laterally to grind the entire edge, but instead kept the blade fixed in one position, to maximize heat build-up in the area marked by the lacquer.
I held the blade in place, under pressure, immobile, until the blade became too hot to hold, which was approximately 60 seconds
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I sharpen my larger blades on an HF 1x30, some of my smaller ones as well, though I do have a DMT aligner set for making pretty even bevels or sharpening when not at home. If I'm hurting my edges on the HF, I've not noticed it yet. YMMV?
 
Anyone with leather belts:

What do you do when its caked with used compound?

I'm talking black and shiny. Belt feels slick. I'm having trouble getting the same results as when the belt was fresh out of the box. I'd rather not buy another, so if there's something I can do to get it closer to new, lmk please.



Thanks
 
Hey Tim what I do is use a piece of steel semi-sharp and place it againt the face of the running belt and use it like a scraper.... its a putty knife like 1" wide. I have 2" X 72" belt grinders and I have one just for sharpening and finishing to satin with scotch bright belts. BTW I use the long side of the putty knife not the 1" face width.
 
Here is the simple fact, heat travels faster through thinner metal areas. The heat disperses into the thicker part of the blade and cools down as it does. If a half inch from the edge, the blade feels hot, like say 170 degrees, then the edge could easily be 2 to 3 to 4 or more times that and the very tip of the edge could easily hit 800-900 degrees. I am saying, if you put your finger over the edge and it feels hot, you likely did damage. This may not be the case with INFI as it is very resistant to heat as Busse stated long ago. But with most other steels, it will be an issue.

Chiral, I suggest you speak with Nathan about overheating 3v. Apparently cpm3V can get HT ruined very easily.

In any case, why chance it. You have a nice blade from whomever, why ruin it by regrinding every time you sharpen. You can maintain an edge on stones or strop or even steel for a very long time. A polished edge will last longer and often appear not to cut as well as a coarser edge. I prefer polished.
 
Cobalt said:
Here is the simple fact, heat travels faster through thinner metal areas. The heat disperses into the thicker part of the blade and cools down as it does. If a half inch from the edge, the blade feels hot, like say 170 degrees, then the edge could easily be 2 to 3 to 4 or more times that and the very tip of the edge could easily hit 800-900 degrees. I am saying, if you put your finger over the edge and it feels hot, you likely did damage. This may not be the case with INFI as it is very resistant to heat as Busse stated long ago. But with most other steels, it will be an issue.

Chiral, I suggest you speak with Nathan about overheating 3v. Apparently cpm3V can get HT ruined very easily.

In any case, why chance it. You have a nice blade from whomever, why ruin it by regrinding every time you sharpen. You can maintain an edge on stones or strop or even steel for a very long time. A polished edge will last longer and often appear not to cut as well as a coarser edge. I prefer polished.
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I agree ^
 
tinfoil hat timmy said:
Anyone with leather belts:

What do you do when its caked with used compound?

I'm talking black and shiny. Belt feels slick. I'm having trouble getting the same results as when the belt was fresh out of the box. I'd rather not buy another, so if there's something I can do to get it closer to new, lmk please.



Thanks
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FWIW, I've had the best results using a small square of some 120 grit sandpaper. Roll it into a tube about 3/4" diameter, and lightly drag that across the leather belt while it's running. This will remove any excess old polishing compound. Rolling up the sandpaper prevents you from putting too much pressure against the leather and damaging it.

In the future, don't let the belt get quite so loaded. Just a little bit of compound goes a long way, and gently clean the belt when you start seeing black streaks. HTH.
 
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