Can't get my CGBJ sharp

E

emt1581

Joined
Dec 28, 2011
Messages
895
I'm not sure if it is the grind or what. I went through a ton of CS, pocket, etc...blades...even a kukri...no problem. But my CGBJ I just can't get a good edge on it. Is there anything I have to do special, again possibly due to the grind, to get this knife sharp?

I'm using a Sharpmaker if that matters. I tried both sets of stones and both angles as well.

I know we aren't supposed to ask about prices here...but does Busse charge to sharpen if I send it back to them?

Thanks

-Emt1581
 
Have you tried the Sharpie trick? It may be that the primary angle is even steeper than the 40* (included) angle on the Sharpmaker. Paint the edge with a black marker, then make a few passes on the sharpener. Look closely at the very edge in good light, even better if you can use a magnifier or a loupe. Are you removing steel at the edge, or behind the edge? If behind, then you need to either remove enough steel to get a new primary grind, or change the angle of your sharpening to remove steel at the edge.

Don't quote me on it, but I think sharpening at the Shop is free, you just have to cover shipping. Call Lexi or Pokey.
 
resinguy said:
Have you tried the Sharpie trick? It may be that the primary angle is even steeper than the 40* (included) angle on the Sharpmaker. Paint the edge with a black marker, then make a few passes on the sharpener. Look closely at the very edge in good light, even better if you can use a magnifier or a loupe. Are you removing steel at the edge, or behind the edge? If behind, then you need to either remove enough steel to get a new primary grind, or change the angle of your sharpening to remove steel at the edge.

Don't quote me on it, but I think sharpening at the Shop is free, you just have to cover shipping. Call Lexi or Pokey.
Click to expand...

Good idea with the Sharpie. I'll try that when I get a chance. And I'll drop Pokey a line. Thanks

EDIT: Something I'm noticing is that the thickness and just overall anatomy of the blade is pretty thick. It's not like a convex grind where it contours in and lets you access the cutting edge with ease. I almost get the feeling (tactile-wise) like the cutting edge is being pushed away from the rods/triangles by the rest of the blade.

-Emt1581
 
No experience with the sharpmaker, but if your having troubles, just ship it back to busse. I'm fairly certain its free as well. Couldn't imagine them charging; their CS is the cats pajamas. If they do charge, send it my way, and I'll convex her for ya ;) You wont need it back, right?
 
SavageSmurf said:
No experience with the sharpmaker, but if your having troubles, just ship it back to busse. I'm fairly certain its free as well. Couldn't imagine them charging; their CS is the cats pajamas. If they do charge, send it my way, and I'll convex her for ya ;) You wont need it back, right?
Click to expand...

I thought about the convexing approach but that would change the integrity of the blade and obviously void any warranty...no?

As a convex edge I think this would be a breeze to sharpen.

Thanks

-Emt1581
 
It's just the bevel, you're not changing the grind. Tons of people convex their bigger Bussekin blades. And yea, I think convex edges are the lowest maintenance, I've only ever had to touch them up. V bevels I often re-sharpen. YMMV.
 
pretty sure reprofiling the edge won't void a busse warranty, but that's something you can call the shop and ask

i think the only thing that voids a busse warranty is intentional destruction
 
I had the same issue with my BJ. ResinGuy is right, the edge angle is quite a bit greater than 40 degrees. This combined with the fact that the BJ is unusually thick behind the edge makes it a little tricky to get right.

In the end I decided to convex the edge with a mousepad and sandpaper and it doesn't look too bad..

The edge on my original TG is similarly thick and to sharpen it I have now used the lansky system (which I didnt have when I was trying to sharpen the BJ) and this has done a great job on the TG. So therefore I wouldnt be surprised if the Lansky system would do a good job on the BJ too.

Failing that, you should be able to sharpen the BJ by hand, just don't make the mistake I made which was to try and sharpen it at about 40 degrees inclusive. As ResinGuy suggests all I acheived was in taking away metal from behind the edge. By hand, slowly and cautiously watching the the stone up and down perfectly flat against the edge angle, preferably underneath a really decent light source should help.

Hopefully you can learn from my mistakes!! Good luck
 
Just send it in to the shop. I will take care of it for you. You just pay the shipping.

Garth
 
I love my BJ...but it did come with a rather obtuse edge and I agree that the blade profile itself is very thick, especially behind the edge. I thinned out the edge considerably...I mean big time (took it up about .25 inch) with a 1" belt sander and strop... It now has a thin convex blended grind. It is ridiculously stupid sharp now...I love it!
 
Raging Rhino said:
I love my BJ...but it did come with a rather obtuse edge and I agree that the blade profile itself is very thick, especially behind the edge. I thinned out the edge considerably...I mean big time (took it up about .25 inch) with a 1" belt sander and strop... It now has a thin convex blended grind. It is ridiculously stupid sharp now...I love it!
Click to expand...


I understand thinning the edge, been there, done that. But ...up about 0.25"...?!?! That can't be right.
 
resinguy said:
I understand thinning the edge, been there, done that. But ...up about 0.25"...?!?! That can't be right.
Click to expand...
It's perfect for my intended purpose for this knife...when I say .25" I mean that the powder coat was removed and polished up that much from the convexed edge. It's still plenty thick behind the edge...and sturdy enough to make kindling and any other general utility task no problem. Cutting flesh, rope, strapping, etc...brilliantly. I'm not one of those guys that intentionally abuses busse knives or wants to use every one of my knives as a chopper or for batoning (which for some silly reason has become the new standard by which every knife is judged). It seems that I'm constantly reading threads where folks expect a single knife to excel at processing lumber, demo work, skinning game, and food preparation...I can only shake my head at this. If I wanted it for chopping down trees, lumber with nails, and other Hard tasks then I would definitely put more angle on the convex...which is what I do for my larger bladed knives.

Here's a pic...it might look thinner than it is...photos can be deceiving.
311convexed-13.jpg
 
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I have my relief grind at 3/8" tall.

consider this: This is the difference between the CGBJ's thickness profile and the TTKZ. Forum member sr223 took the measurements from his CGBJ so I could compare it to my proto.
_________CGBJ_____TTKZ
________(sr223)____(LCV)
1/16_____.070______.051
1/8______.093______.070
1/4______.127______.110
3/8______.146______.145
1/2______.172______.171
5/8______.188______.200
3/4______.202______.220
7/8______.213______.200
1________.223______.250


This is an important graph because the TTKZ is pretty consistently said to be 'too thick' in the edge to perform well as a wood chopper. The CGBJ is thicker up to the 1/2" mark. If a dedicated chopper has too thick of an edge to be where it should be performance wise in chopping, what is it in a 6" streamlined belt knife?

zzP1020699-1.jpg


The CGBJ falls into the catagory G edge in this drawing i made (saber grinds, full flats, convex):
goodbadgeometry.jpg



All of that said, that doesn't make it a terrible knife because it's so thick. It's thickness makes it one of the most capable choppers/prybars/hard use knives in it's size format. You really can't get a stronger or heavier knife in so small a footprint without losing even more cutting performance or adding more weight to the handle. It's a do all knife thats shifted towards hard use/chopping, excellent when paired with a thin ultralight folder/slicer. You do have to do some substantial edge thinner first though.

I did an 18 degree (per side) relief bevel and then a 24 degree primary bevel, so that just above the primary it was .030" thick.
 
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Good stuff LVC! Very informative.
The cgbj is definitely thick for it's profile...especially near the edge, which is the reason I suspect the OP is having such a hard time with the sharp maker, which I think is not well suited for this knife unless the edge is thinned considerably.

LVC, you are obviously using a wicked edge or other controlled angle jig system (18 and 24 deg), what do you use? Your edge is beautiful...very nice. Personally, I've evolved into using power tools for everything except my Japanese kitchen knives or other thin and or delicate knives...which I still do by hand.
 
Raging Rhino said:
It's perfect for my intended purpose for this knife...when I say .25" I mean that the powder coat was removed and polished up that much from the convexed edge. It's still plenty thick behind the edge...and sturdy enough to make kindling and any other general utility task no problem. Cutting flesh, rope, strapping, etc...brilliantly. I'm not one of those guys that intentionally abuses busse knives or wants to use every one of my knives as a chopper or for batoning (which for some silly reason has become the new standard by which every knife is judged). It seems that I'm constantly reading threads where folks expect a single knife to excel at processing lumber, demo work, skinning game, and food preparation...I can only shake my head at this. If I wanted it for chopping down trees, lumber with nails, and other Hard tasks then I would definitely put more angle on the convex...which is what I do for my larger bladed knives.

Here's a pic...it might look thinner than it is...photos can be deceiving.
311convexed-13.jpg
Click to expand...


AH, now I see, literally. 0.25" up on the bevel, makes perfect sense. Looks great, too.
 
here is the relief grinds most everyone has done, then I took it to a full convex,( which should have come like that in the first place).... the blade performs far superior than what it came, and with the relief grinds, mine were done on a 2x72 220 grit-320-then SB belt. this one has been sold on the forum, and my other 2 are the same way now,
 

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I had the same issue with my CGBJ. The sharpie and a ton of time on my worksharp finally produced the edge I wanted.
+1 on LVC. I've followed his post since I joined the forum and would have snagged his custom BJ when he had it for sale, but funds kept me from it. He knows his stuff and I would trust his advice based on previous post. You spend that much time detailing your decision and your shoull be considered a SME. (subject matter expert) or todays PC speak for Yoda.
 
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