View Full Version : mortise chisel sharpening
04-20-2004, 12:52 PM
Where can I drop off my mortise chisels to get sharpened? The local Woodcraft or Rockler?? or is it possible to sharpen them myself?
I bought a set of 4 shop fox chisels, and they are all dull ... i did test cuts with a piece of 2x2 oak and all i got was burning and nothing else ...
04-20-2004, 01:07 PM
It is certainly possible to sharpen the chisel and bit,
The bit is fairly straightforward...just treat it like a conventional woodworking boring bit and dress it carefully with a flat diamond file.
For the cone of the chisel part Rockler sell a diamond sharpening cone #21484 for 7.99.
It stipulates that it is not for use in Drills or drill presses but I would set it up in a drill press to get it exactly vertical..lower it and lock when it is touching and rotate by hand.
Don't forget to lap the square sides of the chisel with a flat waterstone or similar as the last stage before reassembly.
04-21-2004, 07:11 PM
thanks limey! I also found the diamond cones at lee valley ... saw the uses for those ...
for the bits, would the drill doctor work? I don't have one, but was thinking about picking one up ... but I'm not sure if that would work because the bits for the mortise chisel are shaped a little differently.
Also, you said work with a flat file, do i have to work every section of the bit or just the tip that does most of the work?
04-21-2004, 11:15 PM
Your right Sean, They are a bit different and it reminded me that not everyone had the fortunate experience of drilling holes with a brace...geez you have a way of making me feel old !!! :)
So what you have is a old fashioned wood boring bit...it has a wing and a spur.
The spur cuts a perfect circle and the wing follows a bear sixteenth of an inch behind and lifts the wood out of the circle.
The spur is sharpened by gentlyhoning the inside with a single cut slim triangular file or safer for a beginner would be a flat diamond file(it's less aggressive). the object is to remove any burr on the leading edge of the spur without taking anything off its depth..just a couple of strokes will accomplish this.
It should always be deeper than the wing which is on the other side.
The wing slopes up at a slight angle and you need again to swipe off any burr by laying the file or hone on the bottom of the wing and stroking it along the edge at the same upward angle. Don't be too aggressive...if they are the Taiwanese type they are quite soft and one stroke will probably remove the burr that is causing the bit to struggle.
Do not file the outside of the spur as it will no longer cut the correct size hole and the whole set up will be ruined.
Drill Doctor ...no you need to learn the skills of a countrty herbalist :0 :0
04-21-2004, 11:21 PM
Lemme stand up 'longside my friend Limey, hand on shoulder, & attest to the fact that he's given some excellent advice here.
In a case like this, a Drill Doctor would louse up what you wanna' do... the "cure" would be worse than the ailment. :)
-- Tim --
the TOOLS are.
04-22-2004, 07:39 PM
Nothing smells better than fresh sawn wood!
I made the mistake of buying a set of Fox/Grizzley morticing bits (both made by same Chinese factory!) Spent about two hours on each morticer truing up and polishing flat parts using a glass plate and wet/dry paper lubricated w/ water. Then used Lee Valley cone shaped diamond sharpener on inside bevels. A lot of elbow grease but they will at least drill aquare hole in pine. Right now they sit in the box under the work table and have gone back to old standby using a Forstner bit to pre-drill hole and then a SHARP chisel to square up the hole..if I need LOTS of mortices then I use a router with spiral bit and just round off the corners of the tenon.
04-23-2004, 01:19 PM
That's what I was wondering .. I have the cheapo HF Mortiser .. it came with a set of 3 bits that I havn't sharpened yet ... at least they make the holes for me, although they could use some sharpening too .. but I got a what I thought was "better" set ...
these things the drill bit doesn't even bore into the wood, just burns ..
04-23-2004, 01:20 PM
<< looking around my shop ... don't even see a brace around :D
but hey, i've got about 20 hand planes, a dozuki, chisels, and lots of hand stuff that I do :)