RAT-3 Reprofiling with Lansky

S

StretchNM

Joined
Dec 7, 2006
Messages
2,806
OK. I invested in a Sharpmaker. But it was pure hell trying to sharpen my RAT-3. I listened to the experts here and decided I needed to re-profile the edge from 40deg to 30. So...... I invested in a Lansky Deluxe.

I took the Extra Course hone, clamped the knife in well (that was a challenge because of the flat grind, until I learned to clamp it on the 90deg non-ground area near the handle), and started grinding at 17 degrees.

Then, I ground some more at 17 degrees. Then, some more. Several hours and about 300 strokes later, I still had a little of the old profile near the edge! I was so tempted to plug in the Milwaukee 4" grinder but I didn;t want to mess up any of my grinding disks!!!!! Good Lord....either that D-2 is tough, or I don;t know what the hell I'm doing.... or both.

I finally left the tiny bit of old profile on there (especially near the tip of the blade, where it's thickest), smoothed the newly-profiled 17 degree edge out through the Course and Medium stones, then put a 20 degree edge on with the Fine and Extra Fine stones. It still isn't sharp. So I went to the Shaprmaker at the 40 degree setting. It aint sharp.

I'm not giving up....I'll plug in the Milwaukee before I give in. But I would like some input if you fellows wouldn;t mind. Meanwhile, I'm going to join a nearby health spa, pump some iron, and bulk up before I tackle that little RAT 3 again.

Oh. And I've worn that Extra Course down enough to feel it. Should I invest in a course diamond for the Lansky to re-profile edges? I'm thinking maybe if I add some sand-bags to my shoulders, it might give me enough extra weight to bear down and get that edge cleaned up.
 
I mostly use a lansky for the same sort of task, and then sharpen on bench stone.

Does take a while sometimes.
 
If you don't have the Lansky extra coarse diamond hone, go pump some iron. Or just buy one. Even with the X Coarse diamond D2 is a bugger.

Go ahead and sharpen it down till the edge feels rough with that, then polish with the med. and fine.

I usually take mine off the clamp and finish with a benchstone - either a spyderco meduim ceramic, or a arkansas stone if I want extra polish. I like the ceramic for D2
 
I reprofiled the edge angles on my Cold Steel SRK using the Lansky course diamond then worked my way through the other stones. Finished on a hard black arkansas then stropped with leather. That bad boy will shave my fine arm hair now. Very happy with how it worked.

later,

Charles
 
Well, the portion near the edge is the most important, if you leave any of that, you are still not sharpening on the edge, you will see improved cutting ablility because of the thinner profile but in terms of sharpening you haven't changed a thing. This is precisely the reason why many people recomment to pull up a burr. Because only then you know that you have reprofiled all the way to the edge.

Well, now you know why so many complain about the obtuse profiles of tactical knives. Sure you can change the profile yourself.....it is just A LOT OF WORK. And, yes, D2 is very abrasion resistant and hence takes a lof of work to reprofile.
 
Well, I guess I'll get a course diamond.

I went back out in the shop. Colder than hades without a fire. Another 300+ strokes with the Extra Course alone, followed by the Course, Medium, Fine, and Extra Fine. I still have a fine slightly-larger-than-micro-bevel starting where the blade begins its up-sweep all the way to the tip. All 17 degrees. Then I followed with about 15 strokes each side on the Sharpmaker at the 40 degree setting, followed by a few light strokes.

I just can't get this thing sharpened!
 
Have you tried the black marker trick to make sure the sharpmaker really touches the very edge?
 
StretchNM,, do not give up. I had the same problems your having with a Queen D2 slippy. It took *alot* of grinding on a course DMT stone to get the edge bevels where I wanted them. Smoothing them out after that was not to bad and now the blades cut like crazy. Hard work but well worth the effort. Touch ups are not bad as long as I do not let the edges get to far gone.

-DD
 
HoB said:
Have you tried the black marker trick to make sure the sharpmaker really touches the very edge?
Click to expand...

Hob, I tried the magic marker when using the Lansky, that's how I knew I hadn't finished all the way to the edge.... I could still see that tiny black line right at the edge. BUT, I didn;t do it when I went to the Sharpmaker. I figured, most of my edge is at 17 deg, and I'm using 20 deg on the SHarpmaker, so I don;t need the black marker. Hmmmmm. Maybe I should do that, thanks.

DirkDiggler,
Thanks for the support. I won;t give up but I may take a 120V grinder to it! I envisioned 20 minutes....maybe a half-hour, but I've been grinding on that poor thing for several hours! Man, I wish I had half the stamina of D2!!! Now, I aint afraid to work up a sweat in 36 degree weather, but I sure was dissalusioned about how long it would take! I think maybe D2 steel is used for flattening diamond stones when they get dished.

I'm not giving up. What I figured I'd do was just put that 20 degree micro-bevel on it, and do a little more coarse stone grinding whenever I had time, and eventually I'd have the whole edge done. But I can;t even get a nice micro-bevel. I'm going to try what Hob said, the magic marker to make sure the Sharpmaker is getting to the edge.

I appreciate everyone's suggestions. There's a wealth of information in here if it'll just find a way into my head. I've been carrying knives since I was a kid and it's taken me nearly 50 years to decide that I probably ought to learn how to sharpen them. Bonehead.
 
Zip7 said:
If you don't have the Lansky extra coarse diamond hone, go pump some iron. Or just buy one. Even with the X Coarse diamond D2 is a bugger.

Go ahead and sharpen it down till the edge feels rough with that, then polish with the med. and fine.

I usually take mine off the clamp and finish with a benchstone - either a spyderco meduim ceramic, or a arkansas stone if I want extra polish. I like the ceramic for D2
Click to expand...

Zip, I'm going to pump iron AND get a diamond hone. But if it pishes me off any more than it has, I'm going to grind it down to about 5 degrees. I had no idea D2 steel was that tough. All my experience is with woodworking chisels, plane irons, and spokeshave irons. If I'd have ground that much on any of those as I did on that RAT-3, a chisel would just turn to dust. I sharpen them with a jig on wet/dry paper on plate glass.
 
I would use the sharpie marker trick and make sure I set a burr from both sides before moving to the Sharpmaker. Then when you start the Sharpmaker work, be sure the stones are very clean so they will cut and not just smear. Use light strokes on the Sharpmaker since you aren't profiling, just finishing the edge.

Some advise to stop short of a burr with the coarse stones, but if I was having the problem you describe I would show it no mercy. My limited experience is that developing a burr will almost guarantee the darn thing will get sharp.
 
For the same price (or less) of a diamond stone you can get a Harbor Freight 1x30 belt sander and belts. This is the best way for me to work on D2. It will reprofile the edge and get you a burr in just a few minutes.
 
I mess with a lot of slip joint knives, and they tend to come out of the box with bad profiles, et... or people give them to me after they've been severely abused. I find that even a good carbon steel can take a while to reprofile with the lansky Diamond hones.

One of my favorite EDC knives is a cheap Kissing Cranes Trapper w/ carbon blades. Was rather frustrating to reprofile the clip blade to 17 per side on the lansky, but once there, is fairly easy to sharpen on a stone. Queen D2 knives - same way, at least the ones with thicker blades. Thin blades I do on a stone only.

I first heard about Lansky when I was working on an offshore drilling rig in the late 1980's. The Rig mechanic had one, and sharpened every pocketknife on board with it. He told me and I quote, "don't waste your time with the regular kit - go ahead and get the diamond stones." So I did.
 
D2 is really tough, as much as any of the "super" steels. Even with a extra coarse diamond on the lansky, you can expect to be there about an hour. Hell, ATS-34 took 45 mins.
 
Grubbster had some good advice. Invest in a HF sander. Practice on a beater knife first, once you get the technique down, you'll be much happier.

I don't think you'll see much better result from a Lansky diamond stone, partially due to the size. If you don't want to go the HF route, get a large extra coarse diamond or regular stone. You can freehand the initial bevel to get it lower, then set what you want with the Lansky or Sharpmaker.

cbw
 
one thing is if you are actually making it duller you might be only hitting one side of the edge, forming a burr on the other side. This again can be checked with the sharpy trick or checking with your fingernail.
 
Well fellows, thanks for all the helpful advice. I got it done!!!

I now have a nice D2 blade with a 17 degree edge and a 20 degree microbevel. AND, it'll shave hair off my arm the full length of the blade all the way to the tip (well....except for the last half a millimeter or so). I didn;t strop it just took it straight from the flat sides of the Sharpmaker fine stone. Maybe after I get better with the Sharpmaker I'l learn to strop so I can get it "hair-poppin" sharp.

Hehehe. I'm pretty happy. Thanks again!
 
Bill DeShivs said:
Coarse, not course.
Rebevel, not reprofile.
Bill
Click to expand...

Duly noted, thank you Bill.

The "reprofiling" had me stumped a little too, though I didn;t give it much thought... I just used the word without thinking. Then, I saw a post of yours (maybe in this thread) where you made the distinction. Now I see what I was missing:
- reprofiling would be changing the shape and geometry of the blade "profile"
- Rebeveling is what I did..... changed the angle of the edge grind

I joined this forum to be smarter about my knives. I have since been smartened-up on several fronts of the multi-faceted "bevels" of sharp edged tools :thumbup:
 
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