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Sharpen a global knife

Wed Jul 24, 2013 12:36 pm

I have done free hand sharpening in about one year now. I can get the knives sharp enough for normal use (paper cutting sharp). But now I am going to sharpen some global knife for a friend and I have understood that they are very special. Found this information on Santa Monica knife sharpen blog http://www.memagnus.com/wp/

This is how ordinary Global knives (not single beveled) should be sharpened:

- They should be hand sharpened on Japanese Water Stones.

- The edge formation should be slightly convex on the back end of the edge bevel.

- The edge should have a 15° angle, but it is possible to give it a slightly steeper angle if needed.

I will manage the 15 degree angle, but I do nto understand what slightly convex at the back end mean. Should I make a secondary bevel with about 7-8 degree angle and a primary bevel of 15 degree and then blend them together. When I exame the knives the egde is not flat but convex the whole way

Re: Sharpen a global knife

Wed Jul 24, 2013 12:57 pm

I don't sharpen a Global any differently from a Henkel. 17 to 20 degrees or so. Maybe a bit less if you want. If a little thinning is needed you could go lower then come up for a secondary bevel. They're nothing special really. Treat them like any other common kitchen knife. I've never seen a Global that wasn't abused so I can't comment on the OEM edge. All depends what the customer wants.

Re: Sharpen a global knife

Wed Jul 24, 2013 1:26 pm

Yeah, nothing special about a global. We sharpen them on belt sanders.

If you do hand sharpen I would recommend to sharpen as normal and don't take it too high in grit. 2k Naniwa is a good stone for these knives or simply a 1k with a good stropping.

Re: Sharpen a global knife

Thu Jul 25, 2013 6:20 am

When I got my first Global I thought I was the Knife King, (this was many years ago) and wondered how the heck I was going to sharpen it.

Well, I'm definitely not the Knife King and in fact, I just gave that Global away to a friend. As the other fellas have said, sharpen like any other kitchen knife, nothing special or difficult and the 2k edge will startle the owners (who think they are knife kings by the way) at least that is how it is here where I live.

Re: Sharpen a global knife

Thu Jul 25, 2013 8:43 am

I hand sharpen my Globals by first building a relief bevel at the lowest angle I'm comfortable with. As they come with a convexed edge they need a lot of thinning behind the edge. The primary bevel wil be at some 10 degree per side, with a single microbevel on the right face à la Jon Broida at some 35 degree.
Maintenance with a Black MAC rod.

Re: Sharpen a global knife

Thu Jul 25, 2013 9:31 am

For the microbevel, have a look here. It's important to really cut it, and not convex towards the microbevel angle, if you want to preserve performance.

http://m.youtube.com/watch?v=xwnFrjiAA_ ... l=en&gl=NL

Re: Sharpen a global knife

Fri Jul 26, 2013 12:48 am

So I should not try to copy the convex egde the global came shipped with?

Re: Sharpen a global knife

Fri Jul 26, 2013 2:16 am

The Global factory edge shouldn't be the object of special veneration. It's conception has more to do with easy production than with any other consideration.
If you have no grinder, the only way to create a really convex edge is with sandpaper and mousepad. Especially with the Globals you should expect very serious burr problems like a wire edge. Not a good idea.
By freehanding and blending the primary and relief bevel the resulting edge will be quite convexed, anyway.

Re: Sharpen a global knife

Fri Jul 26, 2013 5:38 pm

Just sharpen it like a kitchen knife and don't over complicate it. Start with a coarse stone to set a bevel move to a medium stone to sharpen and use a fine stone to finish.

Re: Sharpen a global knife

Fri Jul 26, 2013 5:40 pm

It's a Global, grab a rock and scratch away.
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