Chisel sharpening question

[Clay Fails]

I have a collected a bunch of chisels over the years including Two Cherries and Lie Nielsen sets. They sharpen up nicely; I have a Tormek and Shapton water stones.

I recently bought a couple Lee Valley PMV 11 chisels to check them out. I am having the darndest time lapping the backs to a mirror finish. They seem to stay "dull" and I just am not happy with tbe edge.

Anyone else have any issues sharpening this steel? Any tips would be appreciated.

[Mike Henderson]

The back of the PM-V11 chisels are flat. You can use them without polishing the back.

I use Shapton stones to sharpen my LV chisels and they come to a very good edge. I use a WorkSharp to set the bevel and then Shapton stones to put a microbevel on the chisels.

Mike

[Derek Cohen]

I have a collected a bunch of chisels over the years including Two Cherries and Lie Nielsen sets. They sharpen up nicely; I have a Tormek and Shapton water stones.

I recently bought a couple Lee Valley PMV 11 chisels to check them out. I am having the darndest time lapping the backs to a mirror finish. They seem to stay "dull" and I just am not happy with tbe edge.

Anyone else have any issues sharpening this steel? Any tips would be appreciated.

What grit are you using?

Mine polished up immediately on 12000 Pro Shaptons. They did not respond with a mirror polish on Sigma 13000 if used wet.

Regards from Perth

Derek

[Clay Fails]

What grit are you using?

Mine polished up immediately on 12000 Pro Shaptons. They did not respond with a mirror polish on Sigma 13000 if used wet.

Regards from Perth

Derek

Derek
When I first got them I started with a 1000 grit Shapton, then 4000 then 8000. The backs just did not have that mirror polish look I'm used to with other plane. Plus I did not feel the edge was as sharp as I'm able to get with my Lie Nielsen's. Then yesterday I started from "scratch" again on one of the LN PMV11's, starting with 1000 grit diamond plate, followed by the 3 Shapton grits. This is just for the back. The bevel I developed at 25 degrees using the Tormek SG 250 stone, followed with a 2 degree or so back bevel polished with the SJ 250 Japanese polishing wheel. I'm happy with the bevel. It' the fact that the steel won't polish up on the back like my other chisels that alarms me. Like I said,the chisels just don't sharpen as well as others,at least for me.

[Jim Koepke]

My experience with a PM V11 blade was a little different than Clay's.

Knowing the standard practice of Lee Valley to have the blade's back flat my first reaction to the gray back was, "Huh?"

Though I could see it was quite smooth. I gave it a bit of work on an 8000 stone to start and could see the gray going away.

Getting an edge to my liking took a bit more work. I guess that is only normal for a blade that resists wear.

jtk

[Chris Griggs]

Don't worry too much about the polish. My PMV11 was harder to get that bright mirror on than my Veritas 01's as well, but the edge was fine. Being a bit obsessive though that didn't stop me from obsessing about the polish also (which in retrospec was probably a waste of time). I kinda wonder if there is some quality to the steel that makes it not get the visual brightness quite as easily in the 8k range (which is what I finish on)...maybe its the wear resistance or maybe there is something else. I haven't had it impact sharpness though. Also, while PMV11 does seem to hone pretty similarly to A2 in general, I wonder if maybe on a large flat back its wear resistance is magnified. I had no issues getting a bright polish on the backs of my 2 PMV11 plane blades but I did at one point try to get a bright polish on the entire back of my 1" chisel which was harder....I got it pretty well polished but the area near the cutting edge has gotten more polished than the rest over time as I mainly just work the first inch or so with routine rehonings. Though I am surprised going back through the grits didn't polish it for you.

Anyway, again polishing appearance aside I've had no issues with sharpness so I'm not sure what to suggest other than to make sure the visual thing isn't just playing mind games with you. If you really want a bright polish right at the edge though I'd say work a smaller area or work on your shapton 8000 longer and allow it to dry...that will definitely increase the polishing effect of the stone. Also, try applying more pressure than usual, for whatever reason I found I got a brighter polish with more pressure. Finally, if you are still having issues talk to someone at Lee Valley and see what they recommend.

[Clay Fails]

My experience with a PM V11 blade was a little different than Clay's.

Knowing the standard practice of Lee Valley to have the blade's back flat my first reaction to the gray back was, "Huh?"

Though I could see it was quite smooth. I gave it a bit of work on an 8000 stone to start and could see the gray going away.

Getting an edge to my liking took a bit more work. I guess that is only normal for a blade that resists wear.

jtk
Jim, thanks for your input. I am going to continue working the back a bit more. Maybe the Rockwell hardness is just enough higher to make polishing difficult.