Wednesday, 31 May 2017

Driveway gates - part 6 - Drawbored and wedged M&T joints

I had used wedged mortise and tenon joints on a previous gate project. One of the problems I found with this technique is the wedges can have a tendency of pushing the joint apart unless you clamp the joints first of all. Once the glue has set there is no issue of course.
The width of these gates is slightly bigger than the capacity of my largest clamps. These clamps have the facility of joining two together.
First of all one of the clamp heads is removed totally from one of the clamps. The adjoining clamp requires its movable clamp head turning through 180 degrees. Then the two clamps are simply joined with a large nut and bolt.zz
The glue up using West Systems 105 and 205 epoxy.
Draw-bored and wedged tenons make for an immensely strong joint

Each one of the tenons has a 5 degree wedge removed from either side of its width. I made a template from 1/4" plywood with the correct angle.
I also used the same template to cut some 5 degree wedges from some 1/2" scrap iroko stock. There are a pair of wedges required for each mortise and tenon joint.

I decided to use the drawboring technique "recently rediscovered" by many woodworkers. If you don't know what this is then Marc Spagnuolo and Christopher Schwarz both describe the technique on their respective websites/blog.

Marc's is here
Chris's is here

I drilled a blind 10mm (3/8") hole 60mm (2. 3/8") from the face of each stile. After dry fitting the tenon into the mortise a bradpoint bit was used to transfer the centre of the hole to the tenon.
The tenon was disassembled and the centre point was then moved 1/16" closer to the shoulder. A 10mm hole was then drilled into the tenon.

A batch of 10mm x 40mm long dowels were sawn to length. Then a 15 degree bevel was sanded into one end of each using a disc sander.

No comments:

Post a Comment