I recently posted a topic on setting up a mortiser and the bit. As for
as I can tell everything is tuned as best an I can get it. The problem
is that I just can't believe the performance I'm getting is normal.
I have to use damn gorilla strength to get through QS white oak and on
some test cuts it started smoking heavily on the first cut. It seems
as though the bit is just crap but its right out of the box and I tuned
it up as per a FWW article I just read. I don't know what brand the
bit is which makes me question it right off. The only other thing I
can think is the bit chisel clearence. I spaced it about 3/16 and it
was horrible and an 1/8" seemed a little better but it feels more like
I'm smashing through rather than cutting. Also the sides of the
mortise are not as smooth as I expect. Is this normal?
What about Delta bits? Pro or Heavy duty? Any advice would be much
appiciated. I spent many moons making the quadraliner bed posts and
want to start on the mortices but I don't want to muck up hours and
hours I've put in thus far.
What sized chisel and bit. 1/2" and larger do require extra effort. By
"tuned" you mean that you sharpened the chisel with a cone shaped stone and
"POLISHED the out side of the chisel to a mirror smooth finish?
It could be a crap bit and chisel if the bit is not clearing out the debris.
> I recently posted a topic on setting up a mortiser and the bit. As for
> as I can tell everything is tuned as best an I can get it. The problem
> is that I just can't believe the performance I'm getting is normal.
> I have to use damn gorilla strength to get through QS white oak and on
> some test cuts it started smoking heavily on the first cut.
Recently had to make some 3/8" M/T joints in white oak.
Based on your previous tale of woe, decided to use a drill press and a
carbide forstner bit.
Clamped a couple of pieces of scrap to hold the part in position and
had at it.
Took about an hour to make 8 mortices.
Used a 4 flute end mill in the drill press to clean up the scallops.
Piece of cake.
BD (in email@example.com) said:
| I have to use damn gorilla strength to get through QS white oak and
| on some test cuts it started smoking heavily on the first cut. It
| seems as though the bit is just crap but its right out of the box
| and I tuned it up as per a FWW article I just read.
Jack Novak (sp?) posted an absolutely first class article here a while
back on how to set up a hollow chisel mortiser. Spacing is the key.
Smoke is not a good thing.
It sounds as if you need to get one of the conical stone sets to
sharpen the chisel. It does take a bit of effort; but not the hurclean
effort you describe. That chisel needs to be razor sharp.
If you burned the bit (look for discolored metal) you may need to
replace it. :-(
DeSoto, Iowa USA
Thanks everyone. I'm buying a new chisel set tonight. I'm going with
the woodcraft brand (Its all they have in stock for 1/2".)
Surprisingly the finish on it is better than most of the others but I
will still give it a tune up.
Thanks also for the spacing tips.
Please do not forget to post your findings after you try your new bit on
the very wood that caused you problems with your current bit.
Maybe the previous owners of your current bit overheated it so its
ability to hold an edge/perform has been compromised?
Everyone mentioned sharpening the chisel. That is a very important step.
Bits can be crap from the factory also. A small file will touch them up and
greatly improve cutting and eliminate the smoke.
Sharpen the flat cutting edge and also the inside of the vertical portion.
Only takes a few strokes to make a big difference.
| Morris Dovey wrote:
|| Jack Novak (sp?) posted an absolutely first class article here a
|| while back on how to set up a hollow chisel mortiser. Spacing is
|| the key.
That's the very article I remembered. Good info! Thanks.
DeSoto, Iowa USA
To give credit where it's actually due - The Forty Cent Method
isn't my idea, but rather, as noted in the page on the method,
was described to me by the Fisch (or is it Fische?) rep at a wood
working show. I just illustrated the method. And someone here
provided the Euro equivalent for the metric folks.
At the time I bought my General International 75-075M tilting
head, XY table unit, good hold down/in device and LONG handle.
I "needed" it. If you look at the first illustration on this page,
and realize that just about everything is held together with
mortise and tenons, some are BIG tenons. you understand why
I "needed" a mortising machine.
The glue up was a "challenge" -
And if you have a lot of M&T joints that have to be glued up
at one time - here's a tip that may save you some grief..
Back to mortising machines - there are a multitude of less than
obvious sources of problems.
1. If your stock isn't prepared properly - flat faces, square
edges, parallel faces, straight edges etc. any one of these
being off will likely bite you in the ass somewhere along the
way. If the face you're mortising isn't parallel to the
face the bit - and chisel - can wander a little.
2. If the part isn't held down on the table AND tight against
the fence the chisel may bind - and raise hell. You should
NOT have to deadblow the part off the chisel.
3. If the back of the chisel isn't set parallel to the fence
you''ll get a skewed up mortise. This is where an XY
table comes in handy - move the fence up to the back
face of the chisel, get the fence and chisel against
each other, lock the chisel down and off you go! The
XY table also makes aligning the bit to a layout line
SO MUCH EASIER.
4. If you "nibble your way" such that the some or most of
the bit is hanging out in the air in the space previously
created, it will wander all over hell - and may burn itself
AND the chisel while making a BAD mortise. Ideally you
want the first pass at the cuts to have the bit surrounded
by wood as the plunge is made. The little bits left after
the first pass should be pretty thin - not beefy enough
to cause the bit to wander - and easy to cut with just the
5. Unless you have a really small bench top unit, with a small
motor, faster is better. Do a series of cuts and really
pull that lever hard and fairly fast. That'll keep the bit
cutting rather than abrading the wood. Big curlies/chips
don't get caught between the bit and the inside of the
chisel. If what's coming out of the opening in the side of
the chisel looks like hairs you're not pulling down hard
enough. Of course, if your motor bogs down significantly
when you do . . .
6. Like bench chisels made from crappy steel, crappy
chisels and bits are worse than none at all. Rather
than cutting mortises, you'll either spend a lot of
time cussing and swearing - or sharpening. I like
the Fisch chisels and bits - and you can pick up a set
of their lower end, but still pricey, sets for a good
"show price" at woodworking shows. NOTE: there
doesn't seem to be a "standard" when it comes to
mortising chisels and bits - where they connect to
the mortiser. Know your mortising machines "sleeve"
(or "sleeves") inside diameter AND outside diameter.
It's a real let down if you get home with your new set
and find they don't fit your mortising machine. Take
the "sleeve(s)" with you when you go to make your
Why not simplify your life and just go with routed mortises
and loose tenons? If you already have a plunge router and
maybe an upcut spiral bit or two the TREND Mortise & Tenon
Jig, without their bits and just their 2 1/8" guide will do
the job nicely - with a bit less grief, cussing and swearing
I just did 24 loose tenon M&T joints for some bonsai stands
I'm making - that's 48 mortises to cut - in three different
lengths. Quick and easier - and NO SMOKE, NO SCREACHING
no sore arm.
Consider this alternative.
Did you have the bit turning at HIGH enough speed? Maybe you're just
hogging out material too slowly. (My very first mortise with my drill press
attachment was tough going until I sped it up. YMMV)
- Owen -
I have said it before and I will repeat myself....
(1) Forget the mortising machine.
(2) Buy a decent plunge router and some spiral bits.
(3) Build one or more jigs to use for mortising.
(4) Stop fighting the wood with difficult tools.
I have a mortising machine with sharp bits and I
still think it's a piece of junk compared to my
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.