Messed up bit/chisel

[Chad Easterling]

I managed to get by 1/2" mortising chisel/bit tangled up with a masonry nail last night. Messed it up pretty bad. I've never had to sharpen the chisel or bit. I was hoping to get some pointers on doing so. I'd like to salvage to set, but I will buy a new one if needed.

Any suggestions greatly appreciated.

Thanks!

[John Coloccia]

Get a hollow mortise chisel sharpener, though I suspect your bit is trashed.

[Kent A Bathurst]

It depends on what "pretty bad" means. If you don't think you can get back to finished surfaces with these tools, then I'd guess you have yourself a custom nail finder for future tasks, and you need a new mortising chisel & bit. But then, if you don't have these tools, you need them anyway because unsharpened hollow chisels are nothing at all like sharpened ones. Worst case, you have a throwaway set to practice on.

Sharpening the two items is pretty straightforward. The 4 outside faces of the hollow chisel are honed flat, just like the back of a bench chisel, on a stone or scarysharp sandpaper, or whatever your sharpening scheme is.

The inside of the hollow chisel is sharpened with a special sharpening cone set [coarse and fine] in a electric drill. Clamp the chisel veritical, chuck in the coarse cone, and - carefully holding it vertical - grind away till you have an even scratch pattern on the entire cone-shaped surface. Repeat with the fine cone. Available lots of places - here is one example [diamond hones at the bottom of the page]: http://www.leevalley.com/US/wood/page.aspx?p=41702&cat=1,180,42240,53317,41702

The spurs on the bit are sharpened with a file. I use an auger bit file I got from Lee valley....but I see it is "no longer available"....hmmmmmm.......here it is on Amazon: http://www.amazon.com/Nicholson-Rectangular-Hand-American-Pattern/dp/B001HWEE0C/ref=pd_cp_hi_0

[Chad Easterling]

Thanks for the info. I'll see what I can salvage.

[Ken Fitzgerald]

Chad,

They actually make a sharpen system for mortiser chisels and a honing system. I use both.

The mortiser chisel sharpener4 I use is from Woodcraft... http://www.woodcraft.com/Product/2001840/616/Mortise-Chisel-Sharpening-KIt.aspx

The honing system for the mortiser chisel that I use is from Rockler.... http://www.rockler.com/product.cfm?page=11153&rrt=1

The sharpening kit will remove metal more rapidly but doesn't leave as sharp an edge, IMO. Most of the time I can hone and it's enough but periodically I use the sharpener first then hone for a final edge.

In your case I think I'd use both....sharpener to try to get an undamaged edge back...then use the diamond cone hones.

I also hone the flat outside edges too.

Good luck!

[Chad Easterling]

Ken,

Thanks for the info and links. I will check them out.

[david brum]

Here's another option that I've had good results with:http://www.rockler.com/product.cfm?page=11153&filter=mortise sharpener. I once also managed to mortise into a sheetrock screw and damage the chisel. I made a wooden block to hold the chisel upright on my drill press table, chucked the coarse grinding cone onto the drill press and carefully removed material until I was past the damage. No big deal. Then you just have to hone the burr off the outside of the chisel and you're back in business. FWW did a very good article about sharpening mortising chisels a while back, by Roland Johnson.

[carl zietz]

I have the rockler kit that ken hightlighted, and it has worked well for me.

[Jon Grider]

Chad, I have several nib mortising chisels that fit Delta and some other brand hollow chisel mortisers with 5/8" shanks. I picked up a box of them that included 3/8 and 1/2 inch bits/chisels at an auction several years ago,and sold some here and on another website. Let me know if you are interested, I'll make you a good deal.

Jon