Getting a tip back on my global workhorse

[fourmations]

Hi all, my first real japanese knife is in progress but my global g4 will still be my go to rough and tumble knife, I'm a novice sharpener but getting a very usable edge on this with my SP1000, this relic is about 15 yrs old plus and it must have had a fall, the tip was pointier, could I just put a k tip on this on a sander? Cheers

 

[deltaplex]

You can K-tip it (red line) if that's what you like. I'd probably try for something closer to the blue line, personally:

Either can be accomplished by just grinding it by hand on a lower than 1K stone, pretty quickly. A belt sander would be faster, and a pneumatic die grinder while running water over the blade will have the macro removal done in about 2 minutes.

 

[fourmations]

You can K-tip it (red line) if that's what you like. I'd probably try for something closer to the blue line, personally:
View attachment 282201

Either can be accomplished by just grinding it by hand on a lower than 1K stone, pretty quickly. A belt sander would be faster, and a pneumatic die grinder while running water over the blade will have the macro removal done in about 2 minutes.

Thanks, real food for thought on the shape there, much appreciated!

 

[fourmations]

You can K-tip it (red line) if that's what you like. I'd probably try for something closer to the blue line, personally:
View attachment 282201

Either can be accomplished by just grinding it by hand on a lower than 1K stone, pretty quickly. A belt sander would be faster, and a pneumatic die grinder while running water over the blade will have the macro removal done in about 2 minutes.

Hi

i assume this steel is pretty tough and wont crack or shatter in a hurry, where i work there is a small workshop, we dont have watercooled grinders or any of that but a colleague is very handy with tools and we have powered sanding disks etc, is water important in the process, could we shape it dry and then do the finishing/polishing on my whetstones, id like to soften the spine while im at it, i pinch grip and the spine is a sharp 90 degrees

thanks

 

[gentiscid]

Get a 400 or lower grit and work on the spine with curving moves to keep the convex shape. You don’t need to go all the way up to the spine. Just reshape the tip and keep using the knife. Will be just fine.

 

[fourmations]

Get a 400 or lower grit and work on the spine with curving moves to keep the convex shape. You don’t need to go all the way up to the spine. Just reshape the tip and keep using the knife. Will be just fine.

thanks, i definitely want to go beyond the "bump" though behind your red marking, like deltas diagram blue line, it will look odd otherwise i think, cheers

 

[gentiscid]

U def can if u want to look the same as before.

 

[fourmations]

U def can if u want to look the same as before.

ah yes, i think i like the smoother gyuto type curve though, when i bought that knife i actually wanted the regular shape chefs knife but it was always out of stock, so i ended up with the "orienetal chefs knife" as they called it, same knife just a different spine shape, cheers

 

[deltaplex]

Hi

i assume this steel is pretty tough and wont crack or shatter in a hurry, where i work there is a small workshop, we dont have watercooled grinders or any of that but a colleague is very handy with tools and we have powered sanding disks etc, is water important in the process, could we shape it dry and then do the finishing/polishing on my whetstones, id like to soften the spine while im at it, i pinch grip and the spine is a sharp 90 degrees

thanks

Water itself isn't important, no. Keeping the steel relatively cool is the important part, so if you're using a high speed rotary tool I'd use water since it can generate a ton of heat really quickly. If you're using a benchtop wheel or a belt grinder you'll have to just do light passes and dunk it in a bucket of water when it's approaching too hot to touch. Global steel is varied depending on when it was made, but it's relatively soft and relatively tough in comparison to something like a Tojiro; I wouldn't worry about trying to soften the spine on it.

 

[fourmations]

thanks for the feedback all, done in a matter of a minute, i did neither the K tip or the softer curve beyond the bump and went with the minimal required as per genticid, i do photoshop and all that in work and did a mock up of each type, neither the k tip or the curve suited the knife, i needed to look at the affect on the entire shape of the blade, the mockup that deltaplex did looked great but when mocked up on a photo of the entire knife (rather than the cropped photo) the inward curve on the spine made it look odd, all purely aesthetics but the bump at the top of the spine actually balances the curved spine, many thanks for all the help, cheers