wanted mortise & tenon tips

I have the Shop Fox Mortiser and the Woodcraft tenon jig for the table saw. I've messed around with it a little back in the summer making some small tables for the patio and they turned out ok with some trial & error. Now I'm in the process of building a Mission sofa table for my daughter out of qswo. Any of you guys have any tips, tricks or things to watch out for so I don't screw this up. I'm working from a set of plans I bought and it has all the measurments but I know how things can go. Little tips & tricks the pro's use to make the job smoother. Thanks, Mike
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Mike S.
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Mike -
I have the General Int'l mortiser and the Delta Tenoning jig. I built some screen doors and found that the walls of the mortise cavity were not as smooth as I would have liked - it was my first time using the machine, so maybe it was my technique, but I *really* had to pay attention to keep all of the mortise plunges in line. I had the work clamped to the fence, but overall I'd say that the mortised "squares" varied by a bit more than 1/32... It took some hand work to clean things up, and they were blind mortises, so the error was covered by the shoulders of the tenon, but still... Not quite sure what I did worng. Perhaps I was trying to cut too fast, tho' the mortiser never labored excessively and I didn't get any squealing or burnign.
One thing I found is that it is CRUCIAL to have the back of the chisel absolutely square to the fence when you install the bit assembly. I finally just brought the fence forward and used that to index the back of the chisel.
I have to build a mission coffee and side table group later this fall. I have the wood, the tools and everything but the time to do it... rrrr... Good luck!
John

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I have GI 50T mortiser and GI Tenoning jig. These tools have been serving me well. My learning experience is similar with Mike.
1. Hollow Chisel Mortiser - use the 40-cent method to set spacing between the bit and chisel - lower the head and use a square against the chisel and fence for accurate alignment - tighten the fence really well (I got 1/4 " problem by failing to do that) - start with the "other" end - go to the "right" end and drill the wholes with 1/32 overlap - leave enough wood for the last bridge
2. Clean the hole with a sharp 3/4 " chisel
3. Tenoning jig - mark the lines on all sides - just to be sure - cut the deep lines along the wood - use a standard spacer (chisel width + saw blade width) to get the sides parallel - make the tenons 1/4 " extra long for through joints
4. Table saw fence - cut the four cross lines against the fence - adjust the blade height 1/32 " shy from the deep lines - use a small plane or chisel for potential final cleanup
5. For stronger (and nicer) through joints - cut openings in the tenons for two wedges - drill a hole at the end of the openings - make wedges from a wood that gives nice contrast
6. Check before glue
7. Glue and hammer in the wedges
8. If the mortise hole was too large or the wedges too narrow - use some wood filler before sanding
9. Enjoy your project =)
Cheers, Ollie

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Get a cranked chisel for cleaning the mortise bottoms.

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Hi, Mike.
I do a lot of M&T work, making windows, doors etc. One thing I find invaluable, even for one-offs, is to make up a rod for the job. This is effectively a full-size working drawing (using the cross-section) taken from the plan and drawn onto conveniently-sized boards.
To give you an example, I use 2 boards to draw a panelled house door. I use 3" x 1" PSE softwood, but MDF, hardboard or ply would do as well for your project. One board is cut (on site) to the exact width of the door opening, the other to the exact length. This way I _know_ that the finished door will fit exactly once I've planed it in on site - no guesswork
Then the cross-section of each member - rails, muntins, stiles, panels and mouldings, including hidden detail, such as tenons, is carefully drawn full-size on the boards in its correct relationship to the other components. Use a very sharp, hardish pencil to give an accurate line. These rods are invaluable for working out the allowances to be made for long-and-short shouldered tenons, many of which have to be subsequently scribed. They also help you to cut tenoned members accurately to length when you're using stopped (blind) mortices.
Once you've drawn out your project, checked and double-checked it with your plans and the job site, then you hide your ruler and plans and mark all of your components directly from the rod. This avoids any measurement/drawing-reading cock-ups and will better allow you to visualise each joint - as you finish a component you lay it out on the rod, and you can see very clearly how the next component is going to go.
Be fastidious in giving every component a face side and face edge mark, then use these marks to determine which side of the component goes against the tool fence. This way, if, for example, your mortice is fractionally off-centre, then it will be fractionally off-centre _in the same direction_ in all your components. In the case of the panelled door I've been describing, if some of the mortices were fractionally off in one direction, and some fractionally off in the opposite sense, it would lead to a twisted door. I hope that makes sense to you.
Bear in mind that some of your components will be handed. So when your're about to cut a mortice, hold the component against the rod, just to double-check that you're not about to cut it on the outside of the component, rather than on the inside.
This may seem a lot of trouble to go to, but believe me, you'll save time and money in the long run by avoiding expensive mistakes. Once the job is finished, you can either store the rods to allow you to make an identical piece sometime in the future or, more often (in my case), you can run a belt sander over them to clean them off for the next job. Some guys give the rods a coat of flat white paint to make the drawing stand out a bit more. I've never bothered, but my eyes aren't a good as they used to be and I can see the day coming when I'm going to have to do the same!
HTH
Frank

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then
direction_
direction,
twisted
I was going to make this same suggestion... With a modification: I always index off the "show side" of an assembly (like the outside of a door). If the thicknesses of stock are off, the offset will show up on the unseen side of the assembly.
I use 1/4" mortises for cabinet doors. If my finished stock is 7/8" I will intentionally *not* center the tennon (1/4,1/4,3/8 spacing) so that it is harder to reverse/flip a non symmetric part. If the difference is structurally insignificant, don't center your mortises; this makes "front" and "back" obvious.
-Steve
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thanks for all the tips. Printed them out and have them in the shop to study over before firing up the mortiser.
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Mike S.
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Mike S. wrote:

this should give you some things to think consider. doesn't go into how to cut them - there are just too many ways to do it. But it does start with the importance of starting with properly prepared stock, reference faces and edges and layout tools and methods. Not a complete set of instructions but should be useful.
http://home.comcast.net/~charliebcz/MTPrimer0.html
charlie b
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Charlie, thanks for the link, lots of good info there. I finally got the table ends done and after a little sanding they'll be ready for some glue. Took quite a bit of chiseling and some shimming. I figure after I get these tables done I'll start to have developed the proper technique and a system to save myself the grief. It sure looks a lot easier when Norm does them.
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Mike S.
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