Sharpening Hollow Mortise Chisel

[Jim Fox]

So I got the Delta Mortiser. Got it on a deal, but never used it. Got it, divorce, moved, hadn't done much with the shop, now I got a buddy that wants me to build him something for his new house and I need to mortise.

So Mr UPS delivers me the sharpening set from Rockler. Harbor Freight supplies me with a cheap drill press vise. So I chuck up the 3/8 bit cause I will need that one first. It seems to be sharp according to the blood I just drew from the points. I've gone thru both honing bits and ran them on 220 grit sand paper as I don't own stones, Yeah, I probably should, but I don't do hand tools either, not yet. Not sure I have the patience for that.

So right now I am fighting the burr issue. If I run the bit on the honing cone the burr is on the outside. If I touch it up on the 220 sandpaper, stuck to my TS table, the burr goes back on the inside. Round and round we go.

In messin with tryin to sharpen the other bits, I have managed to groove up my honing bits quite well. I'm to the point I am just ready to say the heck with it and find some service to do it for me.

Someone talk me down off the ledge please!

[Neil Brooks]

With luck, there'll be some help for you in this article (http://blogs.popularwoodworking.com/editorsblog/Hollow+Mortise+Chisel+Tuneup.aspx).

I got the same sharpening set. Did well by me.

Good luck!

[Jim Fox]

With luck, there'll be some help for you in this article (http://blogs.popularwoodworking.com/editorsblog/Hollow+Mortise+Chisel+Tuneup.aspx).

I got the same sharpening set. Did well by me.

Good luck!

Oh yeah, I found that page long ago. Where I got the details on that set. Somedays u just wanna stick you _____ in a fan. Grrrr

[Darnell Hagen]

Use the cone, then push the chisel, pointy end first, on the paper so the wire edge rolls under and breaks off.

Then give it a spray with Dri Cote.

[Jim Fox]

Use the cone, then push the chisel, pointy end first, on the paper so the wire edge rolls under and breaks off.

Then give it a spray with Dri Cote.

Interesting, I will try that tomorrow. Thanks

[Lee Schierer]

Go to your local automotive store and pick up a pack of sandpaper with fine grits. 220 is really too coarse for what you are trying to do. The smoother the exterior of the chisel is the easier it will cut. In reality the drill bit does 90% of the cutting. Only the corners of the chisel actually cut the wood. Pulling the chisel back out of the wood if the sides are rough will be very hard and 220 grit is pretty rough when it comes to metal. You can mount the sand paper on a piece of wood or better a piece of 1/4" plate glass with spray adhesive. Stroke the chisel like you are trying to shave off the surface of the sand paper and you shouldn't see a burr.

[Aaron Wingert]

I'd also lose the 220 grit sandpaper and go to 400 or preferrably 600 wet/dry. I do mine using a piece of glass or other known flat surface, and I do them wet. I usually hone to at least 1200 grit. I use the rockler cone sharpener for the inside surface first and then hone the outside, which knocks off any burr the cone forces outward. Works great for me and it only takes a couple minutes per chisel.

[Jim Fox]

I'd also lose the 220 grit sandpaper and go to 400 or preferrably 600 wet/dry. I do mine using a piece of glass or other known flat surface, and I do them wet. I usually hone to at least 1200 grit. I use the rockler cone sharpener for the inside surface first and then hone the outside, which knocks off any burr the cone forces outward. Works great for me and it only takes a couple minutes per chisel.

I must of just been off a bit with my alignment to get the honing cones grooved.

[Neil Brooks]

Another interesting/informative article (http://www.woodbin.com/misc/hollow_chisel_mortiser.htm) ... for those who may search this topic, in the future.

[Bob Wingard]

Hone the inside .. polish the outside .. go to work. The burr will fall off the first time you plunge the bit into your workpiece.

Think about what you're really doing with this tool .. .. the plunge causes the corners to dig in and shear the material, gathering it and bringing it to the rotating bit, which clears the debris. The sides of the mortise are NEVER going to be perfect .. good .. but not perfect, so what are you going to gain by getting a perfect edge on the tool ??

[Jerry Wervey]

One other little trick go th e the cupboard and get out the parafin cannning wax> when the machine is turned on make a plunge into the wax go real slow so that it melts on both the bit and auger this will take care of that nasty squeak that you often get Also take a ceramic rod and work the inside of of the bevels you will find that on softer woods that you need to give alitte more room / distance between bit and blade to allow for the sappy wood to work it's way out about an 1/8" more.
Jerry