How to speed up mortise and tenon joinery?

[fobos8]

I'm really chuffed with the feedback you've all given me and will put it all to good use.

How accurate does the rounding off of tenons need to be? Surely its easier to square the mortise accurately that it is to round off. I'm not trying to be negative - just trying to see whether it would weaken the joint if the tenons are not perfectly rounded off.

 

[sometimewoodworker]

I'm really chuffed with the feedback you've all given me and will put it all to good use.

How accurate does the rounding off of tenons need to be? Surely its easier to square the mortise accurately that it is to round off. I'm not trying to be negative - just trying to see whether it would weaken the joint if the tenons are not perfectly rounded off.

Rounding off tenons (or squaring mortices) is unimportant as far as glue joint strength is concerned they are plenty strong enough with gaps at the ends.

The benefit of perfectly fitted M/T comes in registration of parts on assembly and when the glue does not hold well or can creep. Then the exact fitted M/T will resist movement. However you can then run into a hydraulic lock which will prevent the joint from closing correctly.

 

[Chris_belgium]

Imho it's more important to get the shoulders perfectly straight than the tenon itself. This is even more the case when using epoxy (fills the small gaps) glue or drawboring the m&t's. I've sometimes had a real 'sloppy' fit when dry fitting the tenons, but after hammering the drawboring pegs in, the joint was rock solid.

 

[miles_hot]

HOw do you go about drilling for drawboring? Is it just a case of really good marking out or is there some technique to drilling through? On the few times I've actually done MT joints with pegs I'v just fitted the joint, clamped and then drilled through. This has the significant benefit of not needing any marking but it misses the benefit of a drawn joint...

many thanks

Miles

 

[Paul Chapman]

HOw do you go about drilling for drawboring?

Have a look at these http://www.youtube.com/user/LieNielsen# ... AkWMHDKB-E

http://www.youtube.com/user/LieNielsen# ... G1jNQzwvQ8

Cheers :wink:

Paul

 

[MikeG.]

HOw do you go about drilling for drawboring?
Miles

Miles,

drill through the wood containing the mortice first, with the tenon removed. The best drill for this is a spade bit, or a brace and bit, because the point is the most important thing.

Having done your first hole, you offer the tenon in, and drill very gently, just engaging the point. This marks on the tenon the centrepoint of the hole through the mortice. Remove the tenon, and just start drilling a short distance away from the point-mark you have just made. The distance varies with your material and the size of your timber & joint.

Mike

 

[MikeG.]

Have a look at these http://www.youtube.com/user/LieNielsen# ... AkWMHDKB-E
Paul

I love the reference to "an ancient technique, some as old as the 16th century"!!!!!! Well, I regularly see them in 13th century buildings, and have no doubt that they would be found all over wooden parts of buildings over a thousand years old.

Nice little videos......but they take a long time to cover something this simple.....

Mike

 

[miles_hot]

HOw do you go about drilling for drawboring?
Miles

Miles,
Remove the tenon, and just start drilling a sort distance away from the point-mark you have just made. The distance varies with your material and the size of your timber & joint.

Mike

Are there any metrics or ways of working out the distance based on the material and the timber / joint size or is this down to experience?

Miles

 

[Chris_belgium]

HOw do you go about drilling for drawboring?
Miles

Miles,
Remove the tenon, and just start drilling a sort distance away from the point-mark you have just made. The distance varies with your material and the size of your timber & joint.

Mike

Are there any metrics or ways of working out the distance based on the material and the timber / joint size or is this down to experience?

Miles

I did some 'testing' on hardwood, 2mm is perfect, 3 mm was too much, you destroy the peg when you try and drive it in. Offcourse this was on the very large t&m joints, smartest thing to do is make a test piece using the same kind of wood you want to construct the drawbore m&t in.

The way I did it was, drill the mortices, put the tenon in, make a center mark with the drill, take tenon out, then I used a centre punch and offset the drill mark at least 2mm.
The first ones I did I lost a lot of time carefully measuring and trying to get the offset holes the perfect distance. Last ones I did I drilled the offset at least 3mm sometimes even more eyeballing the marking out thus making the marking out a lot faster, and then use a round rasp to fine tune them, wich went really fast, talking about one or two strokes with the rasp to get them to the perfect fit.
There is something strangely satisfying to see a m&t joint getting pulled tight when you drive the peg in

One very important detail is, use a knife to cut a point on the pegs before you drive them in.

 

[OPJ]

Mike,

Spade bit? Seriously??? :shock: That might work on a green oak frame but I wouldn't use one on a fine piece of furniture like that! :wink:

A brad point bit (aka. 'dowel drill') would be better, assuming the dowels are no larger than 10mm in diameter.

I've had similar experiences to Chris - 3mm is too much and can split softwood; 1mm isn't enough; but 2mm seems perfect on hardwoods (I've used it on beech several times).

 

[MikeG.]

Yep, a spade bit! Sharpen the face and the edges and they cut surprisingly well..........but, to be fair, I also gave the option of a brace & bit......

Mike

 

[xy mosian]

Of course there are spade bits with scribe points. Now I wonder which brand they are!

xy

 

[fobos8]

what do others think about rounding off tenons to fit routered mortises?

Is everyone else of the opinion that the rounding off doesn't need to be too accurate?

 

[Paul Chapman]

In my experience it's very easy to round off the tenons accurately and fast with either a block plane or a rasp. Here's one in oak I did as a trial fit (can't remember whether I used a plane or rasp for this)

Cheers :wink:

Paul

 

[MikeG.]

Yep, seconds of a job, with a rasp or chisel. I also chamfer the leading edges of my tenons with a chisel.

Mike

 

[woodbloke]

Many of the mortises I now cut (not all) are through wedged, so the show face needs to be enlarged with a sloping cut by about a mm each side...difficult to do accurately if the mortise is left round. This is the reason that I square up the round ended mortise (from the router) with something like a 6mm chisel - Rob

 

[MikeG.]

Ah yes......well, that's a different thing altogether. They must fit perfectly.

Mike

 

[big soft moose]

having just watched workshop essentials 1 i'd note that mr maskery has a jig for making rounded tennons with a router - which would speed things up a fair bit

 

[fobos8]

Hi BigSoftMouse

I was thinking that a roundover router bit half the thickness of the tenon would be a good idea. Was gonna try on the router table but problem is that the rails I have to tenon are very long.

How do I get to see the Steve Maskery jig. Is it on youtube?

Regards,Andrew

 

[big soft moose]

Hi BigSoftMouse

I was thinking that a roundover router bit half the thickness of the tenon would be a good idea. Was gonna try on the router table but problem is that the rails I have to tenon are very long.

How do I get to see the Steve Maskery jig. Is it on youtube?

Regards,Andrew

have a look on his own site - http://www.workshopessentials.com/ , but i think you may need to buy the dvd W.E 1 ( in which case i'd suggest cutting to the chase and just buying the mega bundle of W.E 1-5 )

you could also send steve a pm as he's bound to know if the clip is anywhere

the jig is one of those where you use the router free - not unlike you do in a 'rat - you can use it on longish rails - but are limited to your safe working height ( I guess you could stand on something to increase that but its probably not recommended)

and I'm a moose dammit , not a mouse :lol: