View Full Version : Initial edge profile and sharpening


wildbill254
12-28-2004, 04:03 PM
How do you create the intial edge on your knives

just curious if you done it blade face up on a round wheel or blade down on a platen. And do you eyeball it or have a jig of some sort. I've been freehanding edge up on a smooth contact wheel with varying degrees of success

then how do you finish off your final edge?

thanks in advance.

Steve
12-28-2004, 06:11 PM
First off, I do it edge up, on about a 45 degree angle, so that the bevel travels up the blade for about 1/4" or so. On a regular serrated grinding wheel, using a 50-50x belt, resting the blade on a tool rest in front of the wheel.

To make things easier and straighter, I scribe a line down each side of the blade, measured in from each edge, with a jig I made, or got form Knife and Gun Supply, so that there is a double/parallel line that goes the length of the edge of the blade. Bfore you mark the edge lines, go over it with teh belt/wheel so that the edge is bright. Grind down to that from each side and then you have an "edge" that is about .060" -.080" thick, roughly. It helps to have the blade on a tool rest/plate - solidifies things, makes it easier.

After heat treat, I grind,f reehand, no rest, eyeballing the edge makein and keeping it straight, down to about .020" - .030", depending on what kind of knife it is. Then grind the rest of the bevel down to that thckness. 14 inch wheel for hunters, 3 or 4" wheel for double edged kinives.

I sharpen, last thing, with a slack blet, using the area of the belt just below the platen, and above the wheel, an area of about 2-3". Bevel each side until the edge is finished, when there is a slight burr running the length of the edge. You can tell,by feel, or by looking at the edge straight-on, in the light, and where it is not sharp, it will show a shiny spot. Then buff both sides until the burr is gone and it's shaving sharp. Don't over-do the buffing. I thinnk, somewhere earlier, in this forum, i described my grinding process. Gil Hibben has a new rough grinding video out. Bet that would help a lot!

Advise, if more info. will help. Happy New Year!

wildbill254
12-28-2004, 06:39 PM
I'm still waiting for your video............ :) :)


Thanks for all the info..


when sharpening above the wheel, below the platten.... is the edge up or down and at roughly what angle It seems this would create a slight convex edge if the belt was slack


Happy New Year and thanks again

Bill

SteveS
12-28-2004, 06:41 PM
Final edge on a finished knife.

I must be weird. Haven't found anyone else doing it this way so don't listen to me, but since you asked.

I rotate the platen up so it is almost level with the ground. 15 degrees off level to be exact. Then I run the belt backwards.

I hold the knife parellel with the ground. This puts a 15 degree final edge bevel on. It's more like sharpening with a stone. Except the knife is level instead of the stone. Hope that makes sense. It helps me make an exact angle.

The belts I use varies, but usually start with 220 ceramic. Then switch to 3m film belts 40, 30. Then Norax 15 and 5. Finally with a leather belt.

Steve

Steve
12-29-2004, 02:16 AM
Edge is up, the belt is not actually "slack" but pretty tight. Technically, though, it is slightly convex, but the width of the bevel is so minimal that it is, as far as I'm concerned, flat. It will not take much to work it down on a stone, steel, diamond hone, etc., when you get to that point once it ineeds touching up. 15-20? is about right, again, depending on the use it'll be put to. Heavier cutting needs a steeper angle, but unless you have a jig, it's not possible to hit that angle exactly. The above is a great idea, I think.

cactusforge
12-29-2004, 10:04 AM
I do as Steve is doing with the belt running backward. If you can't make the belt run backward don't do it with the cutting edge up, after you cut into a belt you will know why!! OUCH!! A DC motor is easy to change direction, just put a switch on it to change the polarity. Ask me how I know this. Gib

Jason Cutter
12-29-2004, 06:38 PM
I do it a relatively quick and easy way - seems to work for me. I use a slack belt using the portion near a contact wheel to limit the amount of slack, edge down, eyeballing the SPINE to control the angle. I slow the belt sleep to 1/2 speed, but not always. I NEVER grind with the belt into the edge. I have shredded 2 belts doing this and been slapped by the belt HARD - I'll never do it again.

Edge thickness depends on the type of knife...

I start with a 120grit J-flex belt to set up the edge first if the edge is thicker, but on most edges I can do this with a 240grit J-flex belt. I grind slowly until I get a burr on the edge. After that all the edge refinement is by hand.

I use a waterstone which is about 1000grit and refine the edge that way. Alternatively, I use medium (grey) Spyderco crockstick. The edge should pop hairs like they were terrified, at this stage.

I finish with a very quick strop, on a hard flat leather strop with compound, just a couple of passes each side at a fairly acute angle, to lightly polish the edge.

I find the wet stone method helps to reduce the possibility of ruining the temper at the edge by overdoing the machine sharpening portion. It is very quick and good practise for field sharpening.

There are MANY MANY ways to skin a cat - I'm not suggesting literally... :D I love cats. Jason.