Which angle to sharpen my BM730??

F

Five O

Joined
Feb 17, 2000
Messages
24
Still trying to get an "edge"! I bought a Gatco "Tri-cepts" ceramic hone. Says that it "automatically" sets the proper angle. In about five minutes I had effectively dulled the edge on my new BM730! Argh!

So now I'm going with the Sharpmaker 204 system (should arive in the mail next week)because of the rave reviews here on BF, and because most say its the most "stupid proof" system available. Thats what I'm looking for in a sharpener!

As many of you already know the Sharpmaker 204 sets for a 40/30/12.5/0(flat) degree angle. Which one is the correct for my BM730S?? I keep hearing about "proper angle", even read it in the FAQ's. but how do I know which angle is correct for my BM730S or any othe given knife??

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Repeat after me...

"Gottahava730"..."Gottahava730"...."Gottahava730"!
 
Five O :

how do I know which angle is correct for my BM730S or any othe given knife?
Click to expand...

You keep lowering the angle each time you sharpen the blade until you reach a point at which the blade chips / dents or otherwise doesn't have the functional level of durability you need. You then back up one step and you are done.

-Cliff

 
On my Benchmades, I start with the 15-degree angles, and take the bevel to within 1/32" of the edge, or even 1/64" if I have the patience. Be warned, Benchmade uses very hard steel, and very thick bevels. The first time you try to sharpen in the 15-degree bevels, it might take you half an hour to an hour. Be patient and don't rush it. Once you grind these in, future sharpenings will go quickly and efficiently.

After that, switch to the 20-degree angles, and then follow what it says in the FAQ -- one side only until you get a burr, then repeat on other side, etc.

Joe
 
Five O,

I was trying to figure out how to get it in my schedule today to send the 204 and had almost decided that I had to wait until tomorrow to send it. After reading your post, I realized that I am dealing with a truely possessed individual here
smile.gif
. Your Sharpmaker goes into Priority mail first thing this AM.!!!!!!!
Mark
 
I to needed an "idiot proof" sharpening system and purchased the 204. I was confused at first about the angles of the system untill I watched the video and read the instructions. 30' or 15' per side is for back bevel to thin the blade directly behind the edge. Edge is then ground at 40' or 20' per side. The rods are not very coarse so I have had no luck obtaining a burr with the system. So far my best results have occured following the directions alternating strokes. Hope this helps.


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"Fear the man who has nothing to lose"
 
Troops,
Thanks for the advice! Keep it coming though. Any "techniques" that anyone has found to make the 204 really work would be greatly appreciated.

Joe T,
Right you are about the steel on that BM730S....It's very hard and very thick! The first time I put that ceramic hone to it I thought I was gonna croak! Started to take it down to the garge and put it on the bench grinder!

Mark,
Yes, I've been quite possesed since I got my new BM730S. Its my first "real knife". I've been working on my gun collection for so long, and its become "somewhat complete", so I've turned my attention to picking up some quality knives for different occasions (i.e. self defense, camping, hunting etc...). Next on my list is a fixed blade BM140/154 Nimravus, and I'm also interested in a Kurki style blade by Cold Steel or one of the others.

My dilema is that I don't want to fork-out anymore cash on the knives until I can figure out how to maintain an edge on them! Its frustrated the hell out of me that I've already dulled the edge on my new BM730! I gotta get this sharpening thing down so I can get some more blades! I appreciate you "toss'in me a deal" on your extra Sharpmaker 204. The check is in the mail and thanks for the fast action priority mail.

So, if you'll excuse me I've got to get down to the basement to clear a spot on the workbench for the Sharpmaker, adjust the lighting, and make sure I've got a good suppy of Killians Red in the "shop refridgerator"!



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Repeat after me...

"Gottahava730"..."Gottahava730"...."Gottahava730"!
 
Five-O,

Using the Sharpmaker, you will be successful eventually if you follow Joe T.'s instructions. And he's right about the need for patience. 30-60 minutes might actually be a conservative estimate for a first-time reprofiling job on a Benchmade blade. I've had it take me as long as 2 or 3 hours! The factory angle tends to vary from one knife to another, or even on different sides of the same blade. Like Cliff said, the "correct" angle is the most accute angle you can get and not have the edge chip on you. (Experience will tell). I wouldn't go out of my way to maintain Benchmade's original factory angle, as it's probably thicker than you need, and less efficient than you deserve. As you sharpen, you can get a clear indication of your progress by painting the edge with a magic marker. If it seems to be taking a long time to sharpen the knife, it's because you have to grind away quite a bit of metal before the edge actually makes contact with the stone. When the edge meets the stone, that's when you'll develop the famous burr. Incidentally, I use a "Sharpie" marker, which is permanent ink. The left-over ink can be wiped off easily with Rem-Oil or WD-40.

Good luck, and have fun.

David Rock

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AKTI Member # A000846
Stop when you get to bone.
 
David,
Thanks for that bit of information. I was curious if it was essential that I maintain the "factory angle" on the blade. Apparently not huh.

The "magic marker" sounds like a great idea too! Sounds kinda like using "metal bluing" on a cars ring&pinion gears to get a good set-up (I'm a "motorhead" so I can relate!).

Thanks for the tips!

------------------
Repeat after me...

"Gottahava730"..."Gottahava730"...."Gottahava730"!
 
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