Securing Mortice & Tenon joints

[macca]

RE wedged tenons, I was taught to allow for the wedge in the shape of the tenon, bit risky that close to the end but if done right there shouldn't be much pressure, just be careful when the frame is being assembled as it will definitely be a weak point if the frame is racked.

on the same subject I was also taught to drill a hole at the bottom of the saw kerf(s) into which the wedge will be driven to prevent any splitting

 

[John on the Wirral]

If you glue and dowel the joints drill a slight off-set ie not perfectly lined up and put a slight lesd-in taper so that when you tap the dowel in it pulls the joint together.

 

[Roberto Flintofski]

Bit of progress, made a simple Jig for doing the tenons with the Router, works well on the long lengths bit of tear out at the sides unless I use a sacrificial piece of timber each time though ! did the shorter lengths on the Band saw which is OK but not as accurate but not bad ... the Timber is proper pants though ! coarse grained and splits very easy !

 

[Jacob]

If you glue and dowel the joints drill a slight off-set ie not perfectly lined up and put a slight lesd-in taper so that when you tap the dowel in it pulls the joint together.

If you do draw bore it's best to drill the hole through the mortice before you cut the mortice so you don't spelch out inside the mortice.

 

[Roberto Flintofski]

Got the Joints nice and tight TBF, Drilled thru so that the point of the drill just comes onto the tenon, remove tenon then drilled slightly farther back about 1.5mm and they seem to pull in tight so actually pleased - wished I had made the 1st section I am doing the one at the back as its all a learning process .... hopefully will all get better the more I do ! rebated out for the glass on the verticals but going to put 8mm tapered back to the inside 'slithers ' in for the bottom glass to sit against then any water from watering will run back off the timber was my plan !!

 

[Jacob]

Got the Joints nice and tight TBF, Drilled thru so that the point of the drill just comes onto the tenon, remove tenon then drilled slightly farther back about 1.5mm and they seem to pull in tight so actually pleased - wished I had made the 1st section I am doing the one at the back as its all a learning process .... hopefully will all get better the more I do ! rebated out for the glass on the verticals but going to put 8mm tapered back to the inside 'slithers ' in for the bottom glass to sit against then any water from watering will run back off the timber was my plan !!

Er - hole in tenon needs to be slightly nearer to the shoulder, not "back". But I really wouldn't bother for your frames they just want cramping up tidily and gluing before you drill through for a dowel peg.

 

[Roberto Flintofski]

Hi Jacob, that's what I have done, back / shoulder as per the sketch below so the tapered at the end dowel pulls the joint up tight, but may thanks for the input

 

[Roberto Flintofski]

Next conundrum is the bottom 500mm is going to be boarded with T&G boards set back so that the grain is tucked back away from the front edge and the board stopped short at the bottom so that it is not sat on anything wet, do I just drill the T&G boards and affix with round head ring Galv nails or glue and fix with the brad gun ? obviously not gluing the T&G parts of the boards to allow for movement, advice as always greatly appreciated

 

[mr rusty]

With that T&G boarding, whatever you do in your nice dry workshop is don't fasten them all together tight. In my experience T&G boards in whitewood will expand/contract widthways 1-2mm each depending on humidity. Also, rather than paint I would be thinking about a spirit based preservative (I use bird brand) which is easy to apply and re-apply and really soaks in - far more likely to get right into the joints on T&G than paint.

If you've got an 18G brad gun I'd use that with SS brads.

 

[Rich C]

SS brads, have you seen the price of them? I'd use galv, but I'm cheap.

 

[Roberto Flintofski]

I'm not cheap, just poor !!

 

[Roberto Flintofski]

So, 50mm galv 18 guage brads or 50mm galv ring nails?

 

[Roberto Flintofski]

getting there slowly

 

[Roberto Flintofski]

Slow & Steady