Recommendation? Grinding out a warp for a tapered tang?

[Diego_B]

So I've come to the conclusion that I have a slight warp in in the tang of one of four kitchen knives that I am doing at the time. My plan for all of them was to put tapered tangs on them. After realizing that one of the blade tangs is warped I thought I could just grind out the warp when tapering the tang? The warp isn't severe but it is noticeable when looking down the spine of the blade. Also, I don't have the ability to hollow grind the tangs before tapering so it is a tad more difficult for me to do I guess.

In this video he talks about grinding out a warp in a tang when tapering it and he says that he "pushes" the tang to accommodate for the warp. This may sound dumb but, which side do I grind to remove the warp? I have also fixed problems like this by using the tempering method and clamping the blade but I just wanted to see if it can be done this way?

 

[Natlek]

So I've come to the conclusion that I have a slight warp in in the tang of one of four kitchen knives that I am doing at the time. My plan for all of them was to put tapered tangs on them. After realizing that one of the blade tangs is warped I thought I could just grind out the warp when tapering the tang? The warp isn't severe but it is noticeable when looking down the spine of the blade. Also, I don't have the ability to hollow grind the tangs before tapering so it is a tad more difficult for me to do I guess.

In this video he talks about grinding out a warp in a tang when tapering it and he says that he "pushes" the tang to accommodate for the warp. This may sound dumb but, which side do I grind to remove the warp? I have also fixed problems like this by using the tempering method and clamping the blade but I just wanted to see if it can be done this way?

Which side of tang you would grind ?

 

[FredyCro]

Blue the spine with a marker, put a knife on a flat surface and mark a line with a drill bit and it will become obvious. Use the line as a reference for your tapered tang. Repeat if necessary, the steel might move when you start removing material on one side only.

 

[Colby L.]

Blue the spine with a marker, put a knife on a flat surface and mark a line with a drill bit and it will become obvious. Use the line as a reference for your tapered tang. Repeat if necessary, the steel might move when you start removing material on one side only.

I recently ground a slight taper into the tang to eliminate a warp. I did as was suggested above but when marking the centerline make sure the knife is lain so its convex side is down (it should be smiling at you instead of frowning) this will ensure the blade portion is flat on the surface and the tang curls up off the table. If you set your marker to the centerline of the blade thickness and run it down the tang you will have the line that N Natlek drew (this will be much harder to accomplish if there is already a distal taper as Natlek shown). They you just grind both sides to that.

Can you just hollow grind with the wheel on your platen?

 

[Diego_B]

Blue the spine with a marker, put a knife on a flat surface and mark a line with a drill bit and it will become obvious. Use the line as a reference for your tapered tang. Repeat if necessary, the steel might move when you start removing material on one side only.

I recently ground a slight taper into the tang to eliminate a warp. I did as was suggested above but when marking the centerline make sure the knife is lain so its convex side is down (it should be smiling at you instead of frowning) this will ensure the blade portion is flat on the surface and the tang curls up off the table. If you set your marker to the centerline of the blade thickness and run it down the tang you will have the line that N Natlek drew (this will be much harder to accomplish if there is already a distal taper as Natlek shown). They you just grind both sides to that.

Can you just hollow grind with the wheel on your platen?

This makes sense. Thank you guys! I have a 2x42 so the smallest drive wheel is the top one since I think bottom larger one would be too big? I will have to experiment with some failed blades.

 

[john april]

i do mostly tapered tangs. you can remove most of the warp with a sharp belt and light pressure. if you are holding the tang with a magnet, amd sure the magnet is not strong enough to flatten the warp. also if you are using liners, black liners will hide the inconsistencies. i grew tired of being very carefull to get a nice flat tang grinding freehand, then getting them back from heat treat with warps and having to fix it, further risking screwing the whole thing up ! . i always grind bevels and tangs after hardening now, with ceramic belts i cannot even tell the difference between grinding hard and soft stainless. now i only have to do it once.

 

[FredyCro]

This makes sense. Thank you guys! I have a 2x42 so the smallest drive wheel is the top one since I think bottom larger one would be too big? I will have to experiment with some failed blades.

I actually grind the hollows on tapered
tangs with the bottom wheel on my 2x42. Its maybe 5" diameter and does a great job on 1/8“ stock. The bigger the hollow the less flattening you have to do. Jjst dont overshoot the profile lines.

 

[Diego_B]

I actually grind the hollows on tapered
tangs with the bottom wheel on my 2x42. Its maybe 5" diameter and does a great job on 1/8“ stock. The bigger the hollow the less flattening you have to do. Jjst dont overshoot the profile lines.

That's good to know that it can be done. I will have to try it out today.

i do mostly tapered tangs. you can remove most of the warp with a sharp belt and light pressure. if you are holding the tang with a magnet, amd sure the magnet is not strong enough to flatten the warp. also if you are using liners, black liners will hide the inconsistencies. i grew tired of being very carefull to get a nice flat tang grinding freehand, then getting them back from heat treat with warps and having to fix it, further risking screwing the whole thing up ! . i always grind bevels and tangs after hardening now, with ceramic belts i cannot even tell the difference between grinding hard and soft stainless. now i only have to do it once.

I am starting to become a more and more of a believer now that grinding before or after ht has little effect on belt life and I don't notice much of a difference in terms of difficulty grinding. Only thing I notice is like you said "now I only have to do it once!".

 

[FredyCro]

One advice is to get the hollow started in one place and then gradually move it across the handle. A holding magnet is great for flattening. Vachon knives has a great tutorial on IG