All About Pocket Knives

I made a pass through the local Goodwill today, I bought a few kitchen knives. One of them is a Case 5" boning knife. I was cleaning them up and sharpening them and the Case struck me as having the potential for a nice slim hunting knife. I would like to change the blade profile. What method could I use that would not alter the temper? I'm leery of turning the grinder loose on it, what about a sanding drum?

Thanks,

Chief

I modify blades all the time on a grinder; the difference is I use a slow moving wet grinder.
Here is a pic of my medium wet grinder. It has about a 7" stone.
There is a plastic tray that sets under the blue stone. It is filled with water when the grinder is in use.
The bottom of the stone runs through the water and is carried up onto the blade constantly.


I also have one with a 10” or 12” wet grinder and a small Craftsman wet grinder I use for tools.
The most likely cause of damage to the blade is from overheating. The fact that the stone moves slowly means it does not heat up as fast, the fact that is runs through a water bath means that is stays cool.


I have also done some modification of my own knives on a belt sander. I move the knife very quickly, working tip to heal, (moving the heat back into the steel instead of out to the tip where it will burn), AND I dip the blade in ice water after EACH pass on the belt, making sure there is NO heat buildup in the steel.

Another tip on modifying steel without ruining the heat treatment is to use new coarse belts. The new belts or sanding drums are sharper and will cut better with less heat. It same logic applies to using a coarse grit abrasive. The cooler you keep the blade the better when it comes to preventing heat related damage to the steel.

If you are not familiar with doing a reprofile on a blade, I would suggest you draw out the shape you want on the blade before you start. That will give you a good idea of when to stop working on a certain area.

If you use sanding drums watch the heat buildup VERY closely. I would check the heat build up every 10 seconds and dip it in ice water. I would also suggest using the largest drum you have with 50 grit or coarser abrasive. A 4” drum would be preferable to a 2” drum. In the first place it will last a lot longer & the abrasive will stay much sharper. As soon as the abrasive starts to get dull, replace it! Otherwise you will have too much heat buildup.

If you have some good hand files, I would suggest you do your first reprofile by hand. The faster a tool removes steel from a blade, the easier it is to make a catastrophic mistake that ruins the blade. Hand files are nice and slow, but if you make a bad stroke you are much less like to destroy your work.

A reprofile can be done on sanding drums, but it would probably be my last choice of methods to use. If you have another cheap knife you don’t care about, I would practice on it first before trying on a knife you want to keep.

I hope this helps.
Dale

Thanks for the info! The wet grinder is out of my league for now, I will try the belt sander method first. The blade has a slight upsweep to it that I would like to level out, then reshape the tip. Not a lot of material. If I am understanding your instructions it matters most to not let heat remain in the steel. I've got .75 in the knife but it is still a nice kitchen knife as is, don't want to ruin it.

I found a lot of deer sheds this spring, the winter was hard and concentrated the deer into the thicker groves. That is where they dropped their antlers making it easy this time. Do the antlers have to "cure" for lack of a better term? Anybody interested in trading?

Thanks Again,

Chief

ChiefAmungum wrote:
If I am understanding your instructions it matters most to not let heat remain in the steel.

Actually I don’t want get it hot in the first place.

Make your passes quickly on the belt; 1-2 seconds per pass, depending on the length of the blade, and work from the tip to the heel of the blade.
I never want the blade to get warmer than is comfortable for me to lay the blade on my cheek.
Fingers are unreliable as they trend to have calluses on them and the nerves do not transmit the heat info as fast as your cheek will.
It takes practice to move the blade quickly and steadily, which is why I suggest a practice knife. With practice you can usually move the knife at a consistent angle in the direction you want to move it, and move it fast enough to keep from burning the steel. If you see the steel start to change color it is too late; the damage is done.

The thinner the blade the quicker it will heat up. The same is true of the width of the blade (top to bottom). That is why the most likely place to burn a blade is at the tip.

Good luck on the project.
Be sure to post pictures when you are done.

Thanks again, I will take a few pics, before, during and after. When it comes time to afix the new handles I'm sure to have a question or two!

Chief