Replies

1. 
   sschefer | May 09, 2002 12:10am | #1

   Well, I know I'm catch h e double toothpicks for this but for through mortises, I drill a pilot hole and use a sabre saw. If the wood is to thick for the sabre saw I use my sawzall. I cut them slightly under and then file them to fit the tennons. I make the tennons first and size the mortise based on the end of the tennon. Yes, I know its not very craftsman like but it works for me.

   Steve - in Northern California

   
   

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   Edited 5/8/2002 5:11:56 PM ET by Steve Schefer

2. 
   NormInFujino | May 09, 2002 01:09am | #2

   You're right about it's being difficult. I haven't done enough to be giving others much advice, but I've also started doing mine from both sides, (including both sides of the walls in order to get them perfectly centered). That means cutting the mortises first since they will be a bit larger than the bit size. For long through mortises I use Forstner bits in the drill press. Shorter ones I do with an upcut spiral bit on a table-mounted router.

   I use a home-made tenon jig to cut the tenons based on the actual mortise size, and try to get them just a tiny bit oversized so that I can use a plane/file/sander whatever to fine tune them down to fit the mortises.

   One problem I think you have to be wary of is the use of chisels, files, and rasps to enlarge the mortise. It's easy to remove too much material right around the tenon's exit hole by holding a rasp at an angle or by cutting with a chisel all the way through from entrance to exit side. With a chisel I find it best to cut from both sides toward the middle.

   As always, your mileage may vary.

1. 
   ReimerT | May 09, 2002 02:12am | #3

   Thanks Norm! When you use a Forstner bit do you set up guides for the chisels to keep the walls of the mortise straight, or is there some other method? Your exactly right that I have removed to much material at the exit with a file. I'd like to find an upcut spiral bit (1/4) with about 3 inches of cutting surface, but I'm afraid it may be to weak for this type of plunge work, if in fact anyone out there makes one. Any suggestions?

   Thanks again,

   Tim

1. 
   NormInFujino | May 09, 2002 05:31am | #5

   I haven't used guides for the chisels, I don't know, maybe I should, but I basically try to avoid enlarging the mortise; I just use the chisels to clean out the non-flat area left by the Forstner/router bit, working from both sides of the hole toward the middle to avoid enlarging the mouths in particular. When size needs adjusting, I try to do it on the tenon side rather than the mortise. Doesn't always work, of course.

   Again, "your mileage may vary."

   Edited 5/8/2002 10:36:06 PM ET by Norm in Fujino

3. 
   RLMillard | May 09, 2002 02:51am | #4

   I bore out the bulk of the waste with an undersized bit and use a wide chisel on the mortise. Any time you are forced cut from both sides, you have to expect some misalignment, so by using a long brad point bit you avoid this pitfall. Be sure to back the exit side up to prevent splintering. Normally I advise against paring the sides of mortises, but this is one time it makes sense. The use of a good mortise gauge also helps, since it gives a clearly defined point to pare to, just be sure to use the same face for a reference. Careful stock preparation is a must(isn’t is always). I make the tenon oversized by a small amount and sneak up on a tight fit with a sharp shoulder plane. A lot of times a through mortise is wedged so you need to only worry about the face of the cheeks, as the wedges close the gaps in the other direction. It is odd that the dovetail gets so much attention, when it is the mortise and tenon joint that is really more difficult to cut.

   http://www.americanfederalperiod.com

4. 
   theRev | May 09, 2002 04:39pm | #6

   Tim,

   If the thru mortise is large enough, use your router for the whole thing. Plunge it about 3/4 of the way from one side, flip it over, drill a pilot hole large enough to slip a bottom mounted bearing/pattern bit into, route the second side to match, clean up the corners, presto. It should match up.

   Scott

5. 
   danwolfram | May 09, 2002 07:34pm | #7

   I am not going to claim that I am any good at it... but I use a marking gauge and a chisel.  It is not that hard, keep the chisels sharp and take your time.  I use blocks of wood and squares to keep the chisel true.  Use the marking gauge to lay-out the tenons and cut them with whatever you have.  I use a tenoning jig on my tablesaw.  Give it a try, you might be suprised.  No noise, no dust, not fast but I find hand work to be very satisfying and worth the extra effort.  Good luck. 

   Dan from CT

1. 
   Alan | May 09, 2002 08:45pm | #8

   Dan,

   Absolutely!  I would add that one ought to use mortise chisels.  Trying to chop a mortise with a bench chisel will ruin your whole day--and the bench chisel.

   If you have a good back saw with cross-cut teeth and another with rip teeth try cutting your tenons with those (though it is possible to do a perfectly fine job with only a cross-cut saw).  Same pleasures apply, and the same lack of noise, dust, danger, irate neighbors, frightened dogs...

   Alan

1. 
   danwolfram | May 09, 2002 09:04pm | #10

   Alan, I just purchased (and sharpened) my first mortise chisel last weekend.  Went through two Marples Blues.  I have some joinery to do this weekend so I'll try it out.  This one mortise chisel cost as much as my whole set of Marples!

   Dan from CT

6. 
   ccampbell | May 09, 2002 09:01pm | #9

   I get good results with the mortising attachment for my 14" drill press and by cutting the tenons on the tables saw with a dado set.  The mortising attachment is kind of a pain to set up compared to a dedicated machine but was much cheaper.

   Before I had the attachment I used a spiral router bit.  It makes a much nicer cut but requires more work.

7. 
   alexlisa | May 09, 2002 11:43pm | #11

   I use a Jet benchtop mortiser for all my mortising. I like the quiet, one step process. I cut through mortises in from the finish side, and all in one go if possible. I use oak scrap to back up the cuts. If I have to flip the stock, I always end up with small misalignments inside the mortise. I used to cut tenons flat on the tablesaw with a dado blade, but the cleanup work on the tenons took too long. Now I use a Delta tenoning jig with a micrometer lead-screw adjuster. I can sneak up on final tenon widths a few thousandths at a time and get perfect fitting joints. It works great and I feel safe using it, as my hands are well away from the blade.