Chisel Sharpening

chisels are one of the simplest woodworking tools but also require some of the most prep to function properly the flat back of the chisel is essentially doing the same job as the sole of a plane in that it becomes the reference surface when you use the tool for paring so it's essential that the whole surface is on one plane is all level from tip to heel you also want to have a high level of polish on the back of the chisel because you have to have the same level of polish on the back at the cutting area as you have on the bevel side what that means is because you're doing a large surface area you have to have the whole thing polished to the same level this means that if you are sharpening with a honing guide or any other method that we've talked about you can't use David Charles Worth's ruler trick which is too bad because it speeds up the process but what happens then is you would put a slight back bend on the tool and you wouldn't be able to pair it would not engage properly so this is a blade that has to be done the full surface now that doesn't mean that you have to do have an optical mirror mirror flat surface from tip to heel everything needs to be in playing with each other but it doesn't have to be an absolute mirror shine back here as long as it's all clean throughout what you don't want is for the edges to crown off or for the tip to crown off and you need to have a Polish as far back as you can get it if you take the time and get the entire thing done great but what's really important is the section out here at the tip and that that then transfers all the way through to the back on one plane now I'm going to work with one of our new chisels just to show to some degree how flat our chisels come out of the box if you're working with another tool you may find that you have to do a lot more work than what I'm going to be doing here the basic principle is going to be the same though the very first thing I'm going to do when I get a new tool whether it's brand new like this one or just new to me is I'm going to check for what I've got to work with if the back of that blade is already flat enough that I can get a polish on the majority of it then that saves me a ton of work so the very first thing I'm going to do is go to my 8,000 grit stone now it's essential that this is flat I already flattened this one the process I would use to do that is to put a pencil grid on so I can see where it is and then using a diamond lapping plate or wet/dry sandpaper on a flat granite plate or a piece of glass make sure that that surface is dead flat because then you have something to control from if this surface isn't flat you have no idea how flat the back of the chisel is now I'm going to divide the stone into three segments I'm going to work off initially off of the first third then I'm going to go two-thirds of the way on and finally I'm going to go off the edge as I go I'm going to go up and back and then do the same at the two-thirds and the same at the third or at the full once I've done that I'll look at the back of the chisel and see what I'm working with I'm going on and off the stone like this so that I don't crown the back of the blade if I create a slight cup which I can by working off of this backside of the stone that's much better than creating any kind of a crown I can get rid of the cup I can't get rid of a crown without a lot of work as soon as I've gone through that full cycle I'm then going to look at the back of the blade and see what I'm working with what I see here is through the whole middle a nice even polish and then just a slight drop at the two outside edges so rather than doing all that work on the 8,000 grit stone I've got a 4000 grit stone here that I'll slip into place and do the same process but at a slightly coarser grid I don't want to go all the way down to 1,000 or 220 unless I absolutely have to and I actually would prefer going to sandpaper like the adhesive back stuff here rather than something like a 500 or 220 grit stone so same operation on the stone only this time once I get through those cycles I'm going to spin it around I want the stone to stay as flat as it possibly can be so by working broader surfaces I'm able to work work flatness into it so now if I look at the back you can see I'm still a little off there so I'm going to lap my stone and I could tell by the color swarf on the stone when I got it flat I didn't need to put the pencil lines on there as I work across here you can see that gray color coming on that's this metal being removed for the swarf so when I work it with the diamond stone as soon as I get rid of that gray color I know it's flat I didn't really have to flatten it at that stage but I like to make sure that I have a consistent flat surface so I know what I'm working with and it doesn't take much time to reflect on a regular basis now I'm going to go back to the 8,000 grit stone and I still have the second side of that stone to work with here again I'm just doing a check I want to see how flight I got it off of the 4000 grit if you look at that in the light you'll see a good even polish running all the way through the middle and about here it flares out and I've got clean polish right out to all the edges from here back I've got a slate ghost line at the tip at the edge I don't have to do any more work to this blade for it to function properly and as I sharpen overtime I'm going to end up bringing that polish all the way out to the edges because every time I sharpen the blade I'm going to be real app aback side on the 8,000 grit to get rid of any burr and to make sure I've got a good clean surface so I can stop right here if you want to take it further keep working on the 4000 grit stone go through that same cycle and get to bring that polish out to the edges but as long as you've got a good polished surface in that first inch or so all the way out to the edges then that's what you're using to cut and everything should work fine so now we'll switch over to actually honing for sharpening and now I'm going to introduce the 1000 grit stone I want to reflash my 8,000 grit it's always a good idea to double-check the other stone if you haven't used it yet from that day so I'm going to take that chisel and go to my stop board now when I sharpen with this style honing guide which is a side clamping guide it's the blade is too narrow to work in this upper jaw point so I'm going to go down here in what I call the lower lower jaw clamp down onto the blade and I've got a series of stops here that work in five degree increments from 25 up to 45 degrees when I drop down into the lower jaw on this jig it changes my angle by about five degrees sometimes it's a little less maybe closer to four degrees that means I'm not going to use the number that's on top of here to dictate what the angle is I want a thirty degree bevel on the blade because this is an a2 chisel and we grind those at 30 degrees so I'm going to work off of my 35 degrees stop because it's about get that lower point about four or five degrees less so I run the blade right out to the stop tighten down so it doesn't shift and if I put a pencil or marker on the bill on the bevel side of the chisel I can see where I'm removing material and where I'm not if I do one quick drag back I can see where that polish is happening and right off the bat you can see I'm hitting at the heel of that bevel now I could make a stop here that's exactly thirty degrees it with this fixture and not have to do what I'm going to do right now but then I'd have more stops on here I'm going to work with the same stop and just go to some sandpaper on my block here and change the angle on the blade just a few passes on a couple different grits of paper here and you can see immediately what's going on I've got a little bit of a skew on there so I want to tip the chisel just slightly that straightens it out I'm going to jump up a grit because I've established scratch pattern from the 220 paper now I'm working at 400 as soon as I eliminate all of the pen marker on the bevel side I know I've changed the angle a couple more strokes here I can't quite feel a burr on the back which is a good thing because I don't want to go all the way down there so I might run the risk of crowning off the tip of the blade gonna just make sure there isn't any burr up and then off the 1,000 grit stone at that new angle I'm gonna work until I can feel a burr on the blade what this means is I'm I'm working at the 30 degree angle or more likely 29 degrees I'm working the full bevel of the chisel as soon as I can feel a burr up I can then switch over to the 8,000 grit I want to ease off the burr wipe off that little wheel and this is when I'm going to introduce my secondary bevel I've got a little eighth inch shim that I put in front of that stop that I worked off of before and that's going to increase my angle by a couple degrees so now when I hit the eight thousand grit stone you can see by the color on the stone I'm getting an even polish all the way across the blade and there's now a secondary bevel right at the tip that gives me a blade a chisel that's ready to use I will hit it on the 8,000 grit stone one more time just to get rid of any burr or trace of a burr that might be there and by doing that I'm then also reestablishing the polish on the back of the chisel I'll use that same process on any chisel that I'm working with and that guarantees that I've got the polish that I need on the back and the cutting edge that I need on the bevel you you

Channel: Lie-Nielsen Toolworks

Views: 357,547

Rating: 4.8082047 out of 5

Keywords: Chisel, Sharp, hand tools, woodworking, sharpening

Id: 9aDPZzMvVTA

Length: 18min 35sec (1115 seconds)

Published: Mon Sep 26 2011