Need Advice on Sharpening PM-V11 Chiseels

[Israel]

Hello (and Happy New Year!),
Just received a set of these beautiful Lee Valley PM-V11 chisels, to add to (?replace) my 30+ year old Robert Sorby ones.  I have been sharpening using Shapton stones (1000, 3000 and 5000) and getting the old Sorby's very sharp (though the edge doesn't last too long)… 25 degree primary bevel, and then secondary bevel, using the Veritas jig.  I have gone through a couple of sharpening cycles with the new PM--V11 chisels, and can't seem to get them as sharp as the Sorbys…. I understand that the PM-V11 steel is harder than the old steel, and wonder if I need to move to a harder stone (?12,000 Shapton)….. to get the PM-V11s new ones as sharp as the old Sorby chisels… any advice would be appreciated!
Thanks,
Izzy

[Israel]

Correction:  The Shapton stones I use are 1000 then 5000 then 8000.  Sorry.

[Derek Cohen]

Hi Israel

I would advise 30 degrees if you intend to chop with the chisels.

The Shaptons you are using are good enough to create a very sharp edge. I can, therefore, only imagine that there is some user-error. You do NOT need to go higher in grit than what you have - that is not the solution.

Make sure that you are honing to the back of the blade (obtaining a wire edge) with each successive stone (a fundamental principle of sharpening) - the PM-V11 steel does require a little more time than O1. I assume that you are only creating a secondary micro bevel (good), and not attempting to hone the full face (a bad idea with a honing guide, since it will create more work than necessary and increase the chance you stop too soon).

There is nothing more to sharpening than that.

Regards from Perth

Derek

[frigator]

Make sure you do the backs. Once you get them polished up to 8000 then you can just hit them with the 8000 each time you sharpen. But a new chisel frequently needs a time spent on the backs. I always use a hand lens to make sure I get rid of the previous grit scratches.

[Derek Cohen]

Please be careful of how you do the backs of these chisels. Lee Valley make them flatter than you could ever do. Do NOT treat them as other chisels. ONLY use your 8000 grit to polish, and only the 1" section behind the bevel.

Regards from Perth

Derek

[AHill]

+1 to what Derek said.  I would suggest you're not spending enough time with each stone.  The smaller (up to 3/8") PM-V11 chisels do come with a steeper 30 deg bevel plus a 2 deg secondary bevel so it's possible the higher bevel angle is making you think they are not as sharp as your Sorbys.  My experience with PM-V11 is that it will get every bit as sharp as O1 steel.

[Israel]

Many Thanks!  I will spend more time on each stone and check for a wire burr before moving on…makes sense that it would take longer because the steel is harder.
Appreciate the help!