Author Topic: Sharpening methods question  (Read 1199 times)

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Online Edward A Reno III

  • Posts: 2662
Sharpening methods question
« on: January 05, 2017, 09:37 AM »
The other day I nicked the blade on my jointer plane.  Since I hone using a microbevel, set on the Veritas MKii honing guide, I decided just to reestablish the whole primary bevel as a way of getting rid of the nick.  I don't have a grinder, so I did it with XXCoarse DMT Diamond stone.  It took a while, but I did eventually take off enough material to remove the nick.  At 1200 I started putting in a small secondary bevel again.  By the time I got to the highest grit, I had a huge burr on the back.  I know in freehand sharpening some people lap the back of the chisel a few strokes on every grit after they've done the bevel on that stone.  But because I use the veritas jig, and I employ the ruler trick, the way I  learned was to do the back just on the final grit, and only after I had taken it out of the jig.  But it just felt wrong lapping the back with such a large burr on the 8000 Shapton stone.  And indeed, when I did some test passes with the blade, although it was otherwise razor sharp, it was leaving a small ridge/track in the middle of the blade, likely from a place where the burr had snapped off (it was in a different place on the blade from where the nick was, so I'm sure it wasn't simply a question of me not having removed enough material to work out the nick).

So I guess my question is in a situation like this, where I'm going to be removing a lot of material and creating a large burr, at what point should I start lapping the back of the blade?  I'm loathe to remove and then reseat the blade in the jig multiple times during the same sharpening session, but I guess there might not be any way around it, as it's pretty difficult to lap the back while the blade is still in the jig.
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Offline HarveyWildes

  • Posts: 260
Re: Sharpening methods question
« Reply #1 on: January 05, 2017, 10:00 AM »
The other day I nicked the blade on my jointer plane.  Since I hone using a microbevel, set on the Veritas MKii honing guide, I decided just to reestablish the whole primary bevel as a way of getting rid of the nick.  I don't have a grinder, so I did it with XXCoarse DMT Diamond stone.  It took a while, but I did eventually take off enough material to remove the nick.  At 1200 I started putting in a small secondary bevel again.  By the time I got to the highest grit, I had a huge burr on the back.  I know in freehand sharpening some people lap the back of the chisel a few strokes on every grit after they've done the bevel on that stone.  But because I use the veritas jig, and I employ the ruler trick, the way I  learned was to do the back just on the final grit, and only after I had taken it out of the jig.  But it just felt wrong lapping the back with such a large burr on the 8000 Shapton stone.  And indeed, when I did some test passes with the blade, although it was otherwise razor sharp, it was leaving a small ridge/track in the middle of the blade, likely from a place where the burr had snapped off (it was in a different place on the blade from where the nick was, so I'm sure it wasn't simply a question of me not having removed enough material to work out the nick).

So I guess my question is in a situation like this, where I'm going to be removing a lot of material and creating a large burr, at what point should I start lapping the back of the blade?  I'm loathe to remove and then reseat the blade in the jig multiple times during the same sharpening session, but I guess there might not be any way around it, as it's pretty difficult to lap the back while the blade is still in the jig.

I've been thinking about the same issue lately.  Once I've gone to the trouble of polishing the back of the blade, I don't want to be always removing burrs at coarser grits - that just puts grooves in the back of the blade that I've already gone to a lot of trouble to remove.  I've wanted to test out just continuing to hone to whatever grit I used to polish the back, and then removing the burr, but I haven't had to regrind a bevel lately.

Offline JJ Wavra

  • Posts: 233
Re: Sharpening methods question
« Reply #2 on: January 05, 2017, 10:25 AM »
When I commission a a new tool, hollow grinding then putting the micro bevel on, I sharpen the tool as I always would at least twice.  Meaning that once the tool is set up, in this case the primary bevel has been reworked significantly, the large burr represents a rather week edge. So to condition this edge to be durable take your normal sharpening process and do it at least two times. For you I gather that you use a micro-bevel and the ruler trick so do that twice on the 8000 stone.  This will help it garner the strength and refinement that is needed for the blade to cut well.  Planes and bench chisels are quite easy in this regard compared to carving tools.  With carving tools I go back and forth quite a bit sharpening then cutting then stropping often needing to strop around 40 times to get the cutting edge necessary.

hope this makes sense.

Offline Wooden Skye

  • Posts: 983
  • My little girl was called home 12-28-15
Re: Sharpening methods question
« Reply #3 on: January 05, 2017, 12:19 PM »
I was taught to remove the burr with each grit I use.  It should only take a few passes so doesn't add a lot of time.  My methods may be wrong technically, but work for me.
Bryan

TS 55, (2) 1400 Guide Rails, 1900 Guide Rail, MFT/3, Domino DF 500, 2 domino systainers, ETS 150/3, RO 90, CT 26, (2) OF1400, RO 150. RTS 400, LR 32 set, PS300 jigsaw, 3 abrasive systainers, (2) sys toolbox, (2) sys mini, clamps and other accesories

Offline waho6o9

  • Posts: 1194
    • Garage Door Handyman.com
Re: Sharpening methods question
« Reply #4 on: January 05, 2017, 12:45 PM »
I was taught to remove the burr with each grit I use.  It should only take a few passes so doesn't add a lot of time.  My methods may be wrong technically, but work for me.


That's the way I sharpen blades and chisels as well.

Online grbmds

  • Posts: 1513
Re: Sharpening methods question
« Reply #5 on: January 05, 2017, 12:52 PM »
I was taught to remove the burr with each grit I use.  It should only take a few passes so doesn't add a lot of time.  My methods may be wrong technically, but work for me.

What do you do, then, to remove the scratches on the back of the blade that are now made by coarser grits than the back was originally lapped with? I think it's possible that a couple of strokes to remove the burr at each grit may not remove all of the coarser grit marks.
Randy

Offline Wooden Skye

  • Posts: 983
  • My little girl was called home 12-28-15
Re: Sharpening methods question
« Reply #6 on: January 05, 2017, 03:07 PM »
I was taught to remove the burr with each grit I use.  It should only take a few passes so doesn't add a lot of time.  My methods may be wrong technically, but work for me.

What do you do, then, to remove the scratches on the back of the blade that are now made by coarser grits than the back was originally lapped with? I think it's possible that a couple of strokes to remove the burr at each grit may not remove all of the coarser grit marks.

Never gave it much thought, I really don't think 2 or 3 strokes would make any difference.  Plus I am working up through the grits again. My water stones are 800, 1000, 4000 and 8000. 
Bryan

TS 55, (2) 1400 Guide Rails, 1900 Guide Rail, MFT/3, Domino DF 500, 2 domino systainers, ETS 150/3, RO 90, CT 26, (2) OF1400, RO 150. RTS 400, LR 32 set, PS300 jigsaw, 3 abrasive systainers, (2) sys toolbox, (2) sys mini, clamps and other accesories

Online Edward A Reno III

  • Posts: 2662
Re: Sharpening methods question
« Reply #7 on: January 05, 2017, 03:12 PM »
This was my exact concern.  But I will try @JJ Wavra suggestion next time I have to reestablish the primary bevel.

The other day I nicked the blade on my jointer plane.  Since I hone using a microbevel, set on the Veritas MKii honing guide, I decided just to reestablish the whole primary bevel as a way of getting rid of the nick.  I don't have a grinder, so I did it with XXCoarse DMT Diamond stone.  It took a while, but I did eventually take off enough material to remove the nick.  At 1200 I started putting in a small secondary bevel again.  By the time I got to the highest grit, I had a huge burr on the back.  I know in freehand sharpening some people lap the back of the chisel a few strokes on every grit after they've done the bevel on that stone.  But because I use the veritas jig, and I employ the ruler trick, the way I  learned was to do the back just on the final grit, and only after I had taken it out of the jig.  But it just felt wrong lapping the back with such a large burr on the 8000 Shapton stone.  And indeed, when I did some test passes with the blade, although it was otherwise razor sharp, it was leaving a small ridge/track in the middle of the blade, likely from a place where the burr had snapped off (it was in a different place on the blade from where the nick was, so I'm sure it wasn't simply a question of me not having removed enough material to work out the nick).

So I guess my question is in a situation like this, where I'm going to be removing a lot of material and creating a large burr, at what point should I start lapping the back of the blade?  I'm loathe to remove and then reseat the blade in the jig multiple times during the same sharpening session, but I guess there might not be any way around it, as it's pretty difficult to lap the back while the blade is still in the jig.

I've been thinking about the same issue lately.  Once I've gone to the trouble of polishing the back of the blade, I don't want to be always removing burrs at coarser grits - that just puts grooves in the back of the blade that I've already gone to a lot of trouble to remove.  I've wanted to test out just continuing to hone to whatever grit I used to polish the back, and then removing the burr, but I haven't had to regrind a bevel lately.
Kapex KS 120 w/UG Cart and Extensions • CXS Set • T18+3 w/Centrotec Installer's Set • PDC 18/4 • TS 75 • TSC 55 • HKC 55 w/420 FSK rail • Carvex 420 w/Accessory Kit • Domino 500 Set • OF 2200 w/Base Accessory Kit • OF 1400 • OF 1010 • MFK 700 EQ Set • LR 32 • MFS 400 w/2000, 1000, and 700 extensions • Rotex 90 • Rotex 150 • LS 130 • ETS-EC 150/5 • ETS 150/3 • RTS 400 • RAS 115.04 • HL 850 • CT 26 w/Long-Life Bag • CT Sys • MFT/3

Offline JJ Wavra

  • Posts: 233
Re: Sharpening methods question
« Reply #8 on: January 05, 2017, 04:43 PM »
With the ruler trick I don't see a need to hone on each grit.  I use a 16,000 shapton as my final stone, around 1 micron size is where I aim for most of my tools final edge, and if there is no micro bevel from either grinding it away or it is a new tool I may take a couple of swipes on a 1,000 grit stone.  However, the shaptons cut so fast that if you take 10 or so swipes I get a bevel on the 16,000.  I move the tool forward and backward as to push the blades metal into the cutting edge making it a stronger.  If you only pull or move side to side you don't get as strong of an edge. This is why when I sharpen I also go forwards and back. 

For those that have a polished back I would not take that to any grit that is lower than the final polish on the tool.  This is where it is so important, in my view, that you have a flat back. I should clarify you don't necessarily have to have a completely flat back, IE a japanese style chisel, but you have to have the area near the tip of the tool flat so that you can remove the burr.  I put the tool down heal to toe then move the tool backwards removing the burr.  Then proceed to move the tool forward and back ten or so times.  If the tool was extremely worn you can also take the tool to a soft wood, I have basswood around all the time,  and run the tools cutting edge through the corner of the wood where long grain meets end grain.  Then just hone the tool again on your finest grit. This conditions the edge further and should help last a while before sharpening. 

Not sure if was clear from the first post I made but I don't just use the final stone twice if there was a nick or new tool.  I actually go through my entire sharpening process twice.  I sharpen free hand for almost everything so that takes maybe 2 minutes.  Also, once I have the edge I want I try to never remove it. Here is what I mean.  For a bench chisel here is my standard operation.  I hollow grind at 25 degrees then I put a secondary bevel on slightly above that with a 1,000 shapton.  Then I put a tertiary bevel on around 30 degrees with the 16,000 shapton.  Then when I go to resharpen I only use the 1,000 shapton a couple of strokes to shrink the tertiary bevel down to a small size but not gone.  Then I go back to 16,000 stone and hone the tertiary bevel which goes quickly because l reduced the size with the 1,000 grit stone. Now I have a great edge and when the secondary bevel gets too large I go back to the grinder and remove the material but not the cutting edge so I don't have to start all over again.

The modern steels on good chisels and irons are very strong and can hold up to this but some tools with softer steel you may have to change the cutting angle higher.

Hope this helps.

Online Edward A Reno III

  • Posts: 2662
Re: Sharpening methods question
« Reply #9 on: January 05, 2017, 05:24 PM »
Thanks for the detailed description of your process.  Do you jump from 1000 to 16000 without intermediate grits on the Shapton?  I go 1200, 8000 and then for some blades I will use 1 micron diamond paste on a piece of hard maple.


With the ruler trick I don't see a need to hone on each grit.  I use a 16,000 shapton as my final stone, around 1 micron size is where I aim for most of my tools final edge, and if there is no micro bevel from either grinding it away or it is a new tool I may take a couple of swipes on a 1,000 grit stone.  However, the shaptons cut so fast that if you take 10 or so swipes I get a bevel on the 16,000.  I move the tool forward and backward as to push the blades metal into the cutting edge making it a stronger.  If you only pull or move side to side you don't get as strong of an edge. This is why when I sharpen I also go forwards and back. 

For those that have a polished back I would not take that to any grit that is lower than the final polish on the tool.  This is where it is so important, in my view, that you have a flat back. I should clarify you don't necessarily have to have a completely flat back, IE a japanese style chisel, but you have to have the area near the tip of the tool flat so that you can remove the burr.  I put the tool down heal to toe then move the tool backwards removing the burr.  Then proceed to move the tool forward and back ten or so times.  If the tool was extremely worn you can also take the tool to a soft wood, I have basswood around all the time,  and run the tools cutting edge through the corner of the wood where long grain meets end grain.  Then just hone the tool again on your finest grit. This conditions the edge further and should help last a while before sharpening. 

Not sure if was clear from the first post I made but I don't just use the final stone twice if there was a nick or new tool.  I actually go through my entire sharpening process twice.  I sharpen free hand for almost everything so that takes maybe 2 minutes.  Also, once I have the edge I want I try to never remove it. Here is what I mean.  For a bench chisel here is my standard operation.  I hollow grind at 25 degrees then I put a secondary bevel on slightly above that with a 1,000 shapton.  Then I put a tertiary bevel on around 30 degrees with the 16,000 shapton.  Then when I go to resharpen I only use the 1,000 shapton a couple of strokes to shrink the tertiary bevel down to a small size but not gone.  Then I go back to 16,000 stone and hone the tertiary bevel which goes quickly because l reduced the size with the 1,000 grit stone. Now I have a great edge and when the secondary bevel gets too large I go back to the grinder and remove the material but not the cutting edge so I don't have to start all over again.

The modern steels on good chisels and irons are very strong and can hold up to this but some tools with softer steel you may have to change the cutting angle higher.

Hope this helps.
Kapex KS 120 w/UG Cart and Extensions • CXS Set • T18+3 w/Centrotec Installer's Set • PDC 18/4 • TS 75 • TSC 55 • HKC 55 w/420 FSK rail • Carvex 420 w/Accessory Kit • Domino 500 Set • OF 2200 w/Base Accessory Kit • OF 1400 • OF 1010 • MFK 700 EQ Set • LR 32 • MFS 400 w/2000, 1000, and 700 extensions • Rotex 90 • Rotex 150 • LS 130 • ETS-EC 150/5 • ETS 150/3 • RTS 400 • RAS 115.04 • HL 850 • CT 26 w/Long-Life Bag • CT Sys • MFT/3

Offline JJ Wavra

  • Posts: 233
Re: Sharpening methods question
« Reply #10 on: January 06, 2017, 11:41 PM »
Yes, essentially no stone other than the 16,000 touches the tertiary bevel.  The exception is if the cutting edge has been degraded to the point where the 16,000 does not hone the edge properly.