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Mortise and tenon ???

8K views 32 replies 12 participants last post by  bobj3 
#1 ·
Finished the dinning room table and naturally the chairs seem next.
Do you mortise with the router ? I see a lot of different jigs including the General tools jig . Any one try this yet ? I want to make matching chairs inlay turquoise etc....
I do also have a mortiser I have used with some sucess.
 
#2 · (Edited)
#3 ·
Chair making requires good tight fitting joints or the chair will have a very short life.
Most woodworkers shy away from chair making for this reason. You will need to make angled as well as straight mortises and tenons for chair making, so whatever jig you choose to buy or make will need to be capable of doing this. Many jigs have only been designed for making straight mortises and tenons. Some can be adapted to do angled joints, but usually require wedges to position the work at an angle to make the joint. I've found that this is method is very time consuming and error prone.

I own a Leigh FMT Pro jig which can easily be set up to make angled or straight mortises and tenons with a router, and the resulting joints fit perfectly. There may be other jigs on the market that can do this, but I have no experience with them.
 
#4 ·
Do you mortise with the router ? I see a lot of different jigs including the General tools jig . Any one try this yet ? I want to make matching chairs inlay turquoise etc....
I do also have a mortiser I have used with some sucess.[/QUOTE]

Bob,
Like every project, there are as many ways to do a project as there are people interested in completing it. On the chairs that I made, I used a router to do the mortising. (Up cut spiral bit). Since that time, I also pitched the jigs used as the project was complete, but I'll try and assist if possible. I started trying to cut tenons to fit my mortises but without great success because of all of the angles. I finally settled on a floating tenon system which worked out quite will and was considerably easier and provided a much tighter fit.
Now as to the jig-----
I cut a rectangular block of wood (3/4") fairly wide at the desired angle of the mortise. (Most of mine were between 3 and 7 deg.) Make your board long enough to handle safely. Then, using my router table, I cut a slot in the jig which was wide enough to accept a guide bushing and the length that I wanted for the tenon. After that, I tacked a board onto the jig 90 deg. to the flat to give something to temporally clamp leg being mortised. I used a 5/16" tendon and rounded the edge to match the mortise. All of the joints were quite snug, but remember that you can also resize the tenon if needed for fit.
Attached are a few pictures to help visualize the process that I used.
Good Luck.. The chairs will definitely give you a challenge.
Dick
Wood Table Plywood Furniture


Wood Plywood Floor Table


Wood Plywood Table Lumber


Furniture Easel Chair Wood Table


Chair Furniture Wood Room Hardwood
 
#5 ·
I am in the middle of making chairs right now. I started in early January. I can offer a couple of points. Firstly the build complexity will vary greatly depending on the chair design. Some chairs have lots of angles as has been pointed out. Some have fairly straight lines and will be much easier to build.
The best way to start is to search the web for chair designs and find one or two that you like and think you can make successfully. Once you have a chair design you can focus on wood and how to make them.
Bear in mind you will be making six or more probably. The project moves from fun to tedium when a lot of boring, repetitive steps need to be done.
You will need a reliable way of making mortises that are dead accurate from one chair leg to the other. Jigs are necessary as well as a mortising machine of some kind. I made a slot mortiser that worked out very well and allowed me to duplicate mortises easily.
Floating tenons are much easier for sure as Dick has pointed out.
Hope this helps. Some of it duplicates earlier posts but it's worth repeating. I'd be happy to offer any additional support as well.
 
#7 ·
Thanks all!
I have decided pretty much the style of the chairs
similar to these Chairs and Barstools,Stirctly Southwestern inc.,Southwest Lighting,wall lights,fabric,ceiling lights,Southwest Lights,Lamps,ceiling fans,Ceiling Fans,lamps They will match the Dinning room table I built There are pictures on the "show and tell ". It looks like most of the joints are square but I want something to use that is accurate and repeatable .The General Tools jig looks interesting and Mama allows one new tool for each project :D . As I see from your replies a lot of thought is needed to find the best way. Can you describe the floating tenon ?
 
#9 ·
Bob14,

To use "floating tenons" you make a matching mortise in both parts, then make a long tenon to fit into them, add glue and clamp together. You really don't need the tenon to be made on one piece. It can be made from separate stock, inserted and glued into mortises in both parts. This is "floating tenon" joinery. A dowel joint is a form of floating tenon joinery.
 
#13 · (Edited)
#16 ·
Hi Bob,
I have the General E-Z Pro Mortise & Tenon Jig. I find it a bit fiddly to set up in the sense that you have to mark the center on every mortise & tenon. If you push the timber up a little to firmly against the positioning bars they deflect up wards which messes up the depth of the cut. If you expect to make spot on joint straight out of the box forget it. Having said that with a little practice you can make very acceptable joints with this jig, but do expect to make a bit of firewood while you practice.
The capacity & specification are
stock 1/2" to 1 1/2" thick and any length.
Mortise & Tenon thickness 1/4", 3/8" and 1/2"
Minimum length M&T Joint 1" +/- 1/8" (depending on bit used)
Maximum length M&T Joint 3" +/- 1/8" (depending on bit used)

Regards
Harold
 
#17 ·
I recently saw where someone had made a mortising jig similar in design to the Leigh FMT jig, but made of wood. It had a tilting panel on the front of it for making angled mortises much like the FMT jig. The only thing that was lacking that the FMT jig has was the pattern following capability. The FMT jig has plastic patterns that you follow with the plate that the router is mounted to that you follow to create a mortise or tenon. The wooden version only had movable stops to set the length of the mortise, but this would be adequate for doing floating tenon joinery at the angles needed for chair making. I've spent about an hour looking for it so I could post a link to it, but haven't found it yet. I'll keep looking and add the link when I find it.
 
#20 · (Edited)

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#23 ·
Bob,
I do my tenons on the tabled saw with a jig I made from an idea in Fine woodworking mag.
This jig will also do raised panel doors and such.
The other jig in the picture is one I made for truing up the front and back of the back chair post. It too came from an idea in Fine woodworking - can't recall the issue but I am sure it is on the net.
I am making 8 chairs and have just finished cutting the front and back legs (posts) and will begin routing the faces of the back legs soon and joining the front legs.
Good luck with your chairs.
 

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#24 · (Edited)
Hi Bill

Me too from time to time if I want the square shoulder type but the router can do it so easy no need to make a easy job hard.

I also made my own tenons cutter for the table saw, see it in my uploads..


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#26 ·
Hi Bill


You're Welcome,,I have stop making chairs :) you can find them every where for a dime and doz. at many garage sales the norm ,, I must have 20 or so hanging up in the garage and 10 or 15 on the patio,I love to pickup old rocking chairs and rebuild them, the BOSS said that's all for now and she wants to put them in a garage sale she is going to have and I said OK but I can get some more :) right :)

I have some rocking chairs that are over a 100 years old but I'm sure they will go for a song in the garage sale, like most things do,, :)

But I'm going to keep the set of (8ea.) old Maple Captain chairs I found for 5.oo bucks each at a garage sale..so to say the deals are out there...

====
 
#28 ·
Not too timely an answer, but I purchased the General mortise and tenon jig to build some wooden storm windows. It's okay but it has a cheesy way of setting the stock at the proper height in my opinion. It uses movable metal arms that also help center the material to be cut. But they flex up and down so getting a consistent height was difficult using them. I finally made a little wood block to give me the consistant depth setting. Also had to mount the jig so I could mount a perpendicular rail below it so the stock I was cutting the tenon on was a true 90 degrees. In all fairness, the pieces of wood I was using were very long and a little difficult to manage. Might not be such an issue with smaller pieces. I cut 70 mortises and 70 tenons and afterwards decided floating tenons would have been a better and faster choice.
 
#29 ·
Just wanted to add that cutting a tenon on a end piece that is a bit wider than the tenon will result in a "fence" on the ends. These have to be removed by reseting the tenon width to a wider setting and removing the material left. In my case I had to reset the jig twice after i had cut the tenon because my tenons were more than 3/8 inch smaller in width than the material. Pretty time consuming if your doing 70 joints. Any tenon maker using the fixed guide hole like the General will have the same issue so it's not a fault of the General over any other similar brand. Just an FYI. The same thing will happen on the edges of the boards if the tenon cut is not almost as wide as the board it's being cut on.
 
#30 ·
Hi Mike

I don't have one but can't you just pop in a bigger bit to remove all the stock without resetting the jig. ? or just use one more router with a bigger bit in place..

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#32 ·
You can in very limited situations as explained in the manual when the 'fence' is on the board sides (not the ends) But you would need to change both the bit size and bushing size to do so and then go back to the original setup for the next tenon which would be even more time consuming. Indeed this is the only way to remove excess material on the boards edges because the width of the tenon is fixed by the bushing/bit combination and there is no adjustment on the jig itself to vary tenon width. Since I had significant material remaining of the ends of my boards, this was not possible in my situation and not in any situation where the width of the board is more than the width of the tenon plus twice the diameter of the router bit.
For example, cutting a 1 inch long tenon on a 2.5 inch board with the router set up for a 3/8 thick mortise leaves3/8 of an inch of material on the ends of the board. Since the bit is 3/8 diameter the jig will likely need to be adjusted twice to remove the remaining material. The necessary adjustment to the jig is the setting for the length of the tenon. It’s hard to explain but becomes self evident once the situation is encountered. The obvious solution is to always make the tenons as long as the board is wide less the bit diameter leaving a narrow shoulder on the ends. That wasn’t possible in my case. Again, not knocking the General jig for this as it’s just inherent to this type jig that uses bushing/bits constrained by a fixed opening. I was not aware of this situation when I purchased the jig.
 
#31 ·
Gary I don't get the shopsmith magazine so don't know what the mods are.

As Mike said the movable arms to set the height flex I got around this problem with a 2mm thick piece of aluminum which I slide between the arms and top. Like Mike I had to fix a perpendicular rail to get an accurate 90 degrees. You would have to do this regardless of the length of the timber.

Regards
Harold
 

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