Andrew Pitonyak
08-04-2014, 11:38 AM
THOUGHT 1 - why a huge back bevel:
I purchased an old Stanley 750 chisel and, like all of the other old Stanley 750 chisels that I own, there was a very serious back bevel (some between 1/8" and 1/4") and the main bevel was seriously rounded (convex).
After spending a bunch of time attempting to flatten the back of my 750s, I fired up my bench grinder and ground the blades past the back bevel. I placed a hollow grind (concave) using my Tormek. After establishing the initial edge as fast as possible, I free handed on my 6000 Shapton, jumped to my Shapton 16000, then I ran the back on a strop that I made to remove any burr.
I was really surprised at how much of a back bevel these chisels had. Of course, after you have a huge back bevel, you will never be able to flatten the back to the end. Was this common practice? Is the whole "flatten the back" thing new? I tried to sharpen these things without flattening the back because I did not want to grind so much off of the chisel. They were certainly sharp, but not nearly as sharp I was able to make it free hand with a flat back after establishing a hollow grind.
Funny how what you thought was sharp a year or so ago no longer seems all that sharp.
THOUGHT 2 - PMV11 on my Tormek:
My PMV11 chisels from Lee Valley came very sharp. Sufficiently so that I polished the back for all of a few seconds and just used them. I had not sharpened them other than that since I have trouble free handing a touch-up as they come from Lee Valley (flat with a micro-bevel).
The Tormek made very quick work of establishing a hollow grind. After that, a few swipes on the 6000, 16000, and a pass on the strop (for the back) and these chisels were very sharp. They actually felt sharper to me than my old Stanleys. I was worried that this fancy metal would give the Tormek pause. Nope, I can now use my new chisels the way I prefer to use them. Fast free hand touch up and get back to work.
THOUGHT 3 - Tormek and beveled edges:
My Lee Valley bench chisels have beveled edges (http://www.leevalley.com/US/wood/page.aspx?p=69847&cat=1,41504). I place the initial grind using the Tormek and the parallel guide. This guide has an edge on the right against which you place the chisel, which should keep it at 90%. The top right corner has some relief cut above it, and, with a narrow chisel (say 1/8") that is beveled, that may allow the chisel to not sit exactly as desired. I even had to be careful with the 1/4" chisel. I used a small square to make certain that the chisel was perpendicular to the front of the carrier. OK, I almost always check this (paranoia), but the others were generally fine even with the beveled edges. For the 1/8", I actually had the chisel so that it was not sitting against that edge because it wanted to roll a bit. I was also careful on how I tightened the sides, since with the narrow beveled edged chisels, they seem a bit sensitive to uneven pressure.
THOUGHT 4 - Tormek and the short chisel:
I have two sets of junk Stanley chisels. One set was given to me by my Father, and the other I purchased to test my sharpening skills. One of the chisels has short enough that I cannot drop it into the standard parallel guide <sigh>. I never did bother to sharpen it on the Tormek until last night. I used the Tormek adjustable tool rest (www.amazon.com/Tormek-SVD-110-Tool-Adjustable-Torlock/dp/B00149L5JG). The handle was still elevating the blade, but I figured that I could get mostly close to the angle that I wanted and it was not critical. OK, now that one is sharp as well.
more thoughts in a few.
I purchased an old Stanley 750 chisel and, like all of the other old Stanley 750 chisels that I own, there was a very serious back bevel (some between 1/8" and 1/4") and the main bevel was seriously rounded (convex).
After spending a bunch of time attempting to flatten the back of my 750s, I fired up my bench grinder and ground the blades past the back bevel. I placed a hollow grind (concave) using my Tormek. After establishing the initial edge as fast as possible, I free handed on my 6000 Shapton, jumped to my Shapton 16000, then I ran the back on a strop that I made to remove any burr.
I was really surprised at how much of a back bevel these chisels had. Of course, after you have a huge back bevel, you will never be able to flatten the back to the end. Was this common practice? Is the whole "flatten the back" thing new? I tried to sharpen these things without flattening the back because I did not want to grind so much off of the chisel. They were certainly sharp, but not nearly as sharp I was able to make it free hand with a flat back after establishing a hollow grind.
Funny how what you thought was sharp a year or so ago no longer seems all that sharp.
THOUGHT 2 - PMV11 on my Tormek:
My PMV11 chisels from Lee Valley came very sharp. Sufficiently so that I polished the back for all of a few seconds and just used them. I had not sharpened them other than that since I have trouble free handing a touch-up as they come from Lee Valley (flat with a micro-bevel).
The Tormek made very quick work of establishing a hollow grind. After that, a few swipes on the 6000, 16000, and a pass on the strop (for the back) and these chisels were very sharp. They actually felt sharper to me than my old Stanleys. I was worried that this fancy metal would give the Tormek pause. Nope, I can now use my new chisels the way I prefer to use them. Fast free hand touch up and get back to work.
THOUGHT 3 - Tormek and beveled edges:
My Lee Valley bench chisels have beveled edges (http://www.leevalley.com/US/wood/page.aspx?p=69847&cat=1,41504). I place the initial grind using the Tormek and the parallel guide. This guide has an edge on the right against which you place the chisel, which should keep it at 90%. The top right corner has some relief cut above it, and, with a narrow chisel (say 1/8") that is beveled, that may allow the chisel to not sit exactly as desired. I even had to be careful with the 1/4" chisel. I used a small square to make certain that the chisel was perpendicular to the front of the carrier. OK, I almost always check this (paranoia), but the others were generally fine even with the beveled edges. For the 1/8", I actually had the chisel so that it was not sitting against that edge because it wanted to roll a bit. I was also careful on how I tightened the sides, since with the narrow beveled edged chisels, they seem a bit sensitive to uneven pressure.
THOUGHT 4 - Tormek and the short chisel:
I have two sets of junk Stanley chisels. One set was given to me by my Father, and the other I purchased to test my sharpening skills. One of the chisels has short enough that I cannot drop it into the standard parallel guide <sigh>. I never did bother to sharpen it on the Tormek until last night. I used the Tormek adjustable tool rest (www.amazon.com/Tormek-SVD-110-Tool-Adjustable-Torlock/dp/B00149L5JG). The handle was still elevating the blade, but I figured that I could get mostly close to the angle that I wanted and it was not critical. OK, now that one is sharp as well.
more thoughts in a few.