hand done m/t's

[engineer one]

thanks wiley, i note that hayward is one book i don't have, but i do have joyce so i'll have to look more carefully. :?

since my top rail is halfway down it can't be a dovetail, whilst on the legs i am not too interested in through, stickley type tenons. but will take all onboard and consider.

paul :wink:

 

[woodbloke]

Engineer one wrote:

is there a sort of standard in the same way there is a standard that seems to say that the tenons should be about 1/3rd the width of the wood???

Paul - that's about it, nothing hard and fast. Depth of the mortice should be about 2/3rd the thickness of the leg. The basic rule of thumb with m/t joints is that everything can be roughly subdivided into 1/3rds when working out the proportions of the joint - Rob

 

[engineer one]

well finally made my first test one tonight. m/t that is. about 20 minutes to get it sorted. :lol:

got a couple of the offcuts sorted, and made a square mortice, hand wacked chisel, and then hand sawed the tenon. not too bad, but i think i know why people use the table saw to cut the tenon, or rout it.

anyway now to get the table legs sorted out and set up for morticing.

paul :wink:

 

[bugbear]

For the depth control you can help with a bit of tape wrapped on the chisel. A little practice will make you reach for the combination square at the right moment. BTW it is not only good for measuring depth but squareness too.

Superb!

You might find that a depth gauge or double square is more convenient for checking mortises than a combination square, which can be rather large.

Examples from APTC:

http://www.axminster.co.uk/product.asp? ... e=1&jump=0
http://www.axminster.co.uk/product-Groz ... -22219.htm
http://www.axminster.co.uk/product.asp?pf_id=207669

BugBear

 

[MarcW]

...and then hand sawed the tenon. not too bad, but i think i know why people use the table saw to cut the tenon, or rout it.

paul :wink:

Hi Paul,

In order to adjust the thickness of the tenon cheeks parallel to the work piece, you can use a router plane set on top of it and take shallow shaves. A bit like this:

Superb!

You might find that a depth gauge or double square is more convenient for checking mortises than a combination square, which can be rather large.

Examples from APTC:

http://www.axminster.co.uk/product.asp? ... e=1&jump=0
http://www.axminster.co.uk/product-Groz ... -22219.htm
http://www.axminster.co.uk/product.asp?pf_id=207669

BugBear

Bugbear,

Now that I received all the tools and oils on the bench top this week, you dare proposing me to buy another one #-o...

... Thank you very much :mrgreen:

One question though, is the sliding square from Axminster comparable in quality to the Starrett pendant?

 

[ike]

Given the price I doubt it is near the quality of the Starrett, however it may well be perfectly good enough.

 

[bugbear]

Superb!

You might find that a depth gauge or double square is more convenient for checking mortises than a combination square, which can be rather large.

Examples from APTC:

http://www.axminster.co.uk/product.asp? ... e=1&jump=0
http://www.axminster.co.uk/product-Groz ... -22219.htm
http://www.axminster.co.uk/product.asp?pf_id=207669

BugBear

Bugbear,

Now that I received all the tools and oils on the bench top this week, you dare proposing me to buy another one #-o...

... Thank you very much :mrgreen:

Nice Axe!! Who's it by?

One question though, is the sliding square from Axminster comparable in quality to the Starrett pendant?

Unlikely...
Alf reviewed it here:
https://www.ukworkshop.co.uk/forums/viewtopic.php?t=3738

I have no knowledge of the APTC Engineers-Adjustable-Square since I own a Moore & Wright version (and a Starrett version....)

BugBear

 

[engineer one]

thanks marc, the problem was not in adjusting the cheeks, but in my c**p sawing around the base, let alone the sides of the cheeks :lol:

so back to the practice of cutting straight lines :roll:

paul :wink:

 

[MarcW]

Bugbear,

It's a Gransfors splitting axe.

Thanks for the link to Alf's review, this way I won't buy, because I can't work in imperial

I will have to rely on a Starrett or maybe an old Stanley


Paul,

My sawing isn't terrible too by instance, look here:

...so I make a run around by the shoulder plane and a chisel.

Thanks,

 

[engineer one]

marc, would that my sawing was as good as yours.

much practice for me i guess. :?

paul :wink:

 

[engineer one]

more questions :?

if you do not want the rails to be in the centre of the legs,
is there anything else that should change??
should the mortice or tenon be smaller?

this weekend for the courage :roll: :twisted:

paul :wink:

 

[MikeW]

Hi Paul,

In general, the mortise size is taken from the tenon size. So if I was placing an apron on a table, and the apron wasn't the same thickness as the legs they would be attached to, the tenon on the apron pieces would determine the size of the mortise.

Placement is a semi-related question. If I was wanting a 4 mm set-back, the mortise placement is altered as compared to wanting the apron and leg fronts to be flush or centered.

Example...45 mm legs where the apron attaches. 18 mm apron thickness. 4 mm shoulders around apron tenons. Perhaps wanting a 4 mm set back.

Tenon equals 10 mm in thickness. Forward edge of the leg mortise is set in 8 mm from front (4 mm set back + 4 mm shoulder).

(Which leaves about 22 mm behind the back edge of the apron to back edge of leg.)

Poor example, but you get the idea...

Take care, Mike

 

[engineer one]

where would i be without you guys ta mike that seems to do what i thought
but in this time you seem to be suggesting make tenons first

paul :wink:

 

[Wiley Horne]

Paul,

Most times, I'm working with legs that are not real thick--like maybe they're 1-1/2" to 1-5/8" square (~37-40mm). In this situation, I'm trying to maximize the insertion of the rail tenons, given that there will be tenons coming in at right angles in the other face. The greater the insertion, the greater the glue area.

To maximize the insertion, the tenon will need to be located toward the outer part of the leg. But how far out? Well, I would say that the leg mortises will need to be inset 1/4" to 5/16" (say 6.5 to 7.5mm) from the outside of the leg, so they're surrounded by enough meat that they won't get blown when you chop the mortise, and so the leg doesn't distort outward or split when you push the tenons into the mortises. Now if the legs are thicker than this, these numbers aren't so critical, and you can come in further, say 9mm, and still get long tenons in there.

But in any event, what controls is your judgment about how far in from the edge of the leg you want the mortise to be. As soon as you decide (a) the mortise location, and (b) the inset of the panel from the outer leg face--then the location of the tenon in the width of the panel is specified.

So, suppose it's a 40mm square leg, and a 2mm inset of the panel from the leg face (to create a shadow line). I would inset the mortises 7mm from the outer edge of the leg, and use 6mm to 7.5mm tenons (approx., depends on available chisels!).

So this would mean that the opposing tenons would meet in the leg, at a max. insertion of 40mm-7mm = 33mm, with the ends of the tenons mitered where they meet.

In general, the tenons would be offset in the width of the panels, to satisfy the mortise location and the offset from the leg. In the above case, the tenon's outside shoulder would be, say, 7mm (mortise inset) minus 2mm (panel inset from leg) = 5mm. So if the panel is 18mm, then the outer shoulder of its tenon would be 5mm, then say a 7.5mm tenon, then a 5.5mm inside shoulder.

All of these measurements, once decided, would be marked by gauge, of course, with no need to keep track of numbers in marking out.

Wiley

 

[MikeW]

Ha, Sir Wiley took much more time than I did--I used even, round numbers. The description I used above was simply as the numbers came to me. :lol:

Nah, I generally chop the mortises first, Paul, then gauge the tenons. I will decide which mortise chisel to use by how thick a tenon I desire. But I do gauge off the mortise before marking and cutting my tenons. When all goes as it should, the gauge I use to lay out for the mortises doesn't change when I mark out for tenons.

The reality is that though the numbers above works out to roughly a 3/8" mortise, I would actually use a 1/4" M&T. I used the numbers above because converting was easier in my head. This does create an offset tenon (to the outside, deeper shoulder on the inside). The purpose is as Wiley says, to create a longer tenon.

Should both mortises run together, I sometimes miter the tenons where they meet. But often on a smallish table which is longer than deep, I will create as long a tenon on the front apron as I can, and where the tenon from the side aprons would meet them, I shorten those tenons. Once a tenon is an 1" long in such a situation, I go the easy route.

When chopping mortises in narrow legs like Wiley and I gave an example of, I will often clamp the legs together so the side walls all support each other. On the last one, I'll clamp a scrap of wood. This minimizes the chance of blowing out a mortise. I chop them all when they are together.

Take care, Mike

 

[Anonymous]

how do you "guarantee" that you get the mortise holes at the same height on each of the four legs?

Mark up from a rod i.e. you put all the marks on a bit of board and then take them off onto the workpieces. Traditional, fast, accurate, eliminates errors - and all the measuring/calculating you need to do is only done once

setting the mortice gauge

I do it from a scale, after all the chisel is usually designed at 1/2" or whatever. It's surprisingly hard to do it accurately from the chisel itself. Or stick the chisel in a bit of scrap and set the gauge to the mark.

depth - doesn't matter as long as it is long enough and doesn't go right through

i wonder at the need for a design that demands after construction adjustment

It's normal practice to make components over length by 1/2" or more. This protects the end whilst handling etc and helps give a perfect finish when for instance you finally cut off and plane back a finished through tenon, or adjust the length of table legs as in this case

I see there is a picture of a 4 shoulder tenon. In fact this is a very unusual tenon and I can't think of a situation where one would ever want to use one. No doubt someone will put me right on this!
The most common tenon at the corner of a frame (or table leg/apron etc) would have 2 shoulders only, and a haunched (square or tapered) tenon.
Next most common at a T junction would be a full width tenon with 2 shoulders only.
Both of these might be done flush (one shoulder) where the tenon meets a thicker piece with the mortice in it.
But 4 shoulders never. Or hardly ever.

I generally chop the mortises first, Paul, then gauge the tenons

I'd mark up all the mortices and all the tenons with the same gauge set, before cutting anything.

cheers
Jacob

 

[engineer one]

welcome back jacob, and thanks for that.

i'll investigate my rod making again

paul :wink:

 

[engineer one]

having checked "at last" my copy of joyce, he recommends four shoulder tenons, even if the bottom one is quite small, to ensure that you cover any problems in the mortice itself. even tage frid seems to suggest that way too. :roll:

it is relatively easy i think either by hand or machine to saw the shoulders
straight, but takes some practice to get the mortice sides even and level.

mind you here speaks a man who still finds hand sawing straight a real pita.

paul :wink:

 

[MarcW]

...

I see there is a picture of a 4 shoulder tenon. In fact this is a very unusual tenon and I can't think of a situation where one would ever want to use one. No doubt someone will put me right on this!
...

Jacob,

It is my four shoulder tenon, I guess. I won't correct you, why should I? I'm teacher, but that's no reason. :lol: Indeed I come to do tenons scarcely and I wanted to go sure hiding my mistakes. Indeed if I do just two shoulders, the joint is stronger, because wider, but any mishaps in the mortise will show up. So, that's the reason. For me professionals with a lot of everyday practice can do that, for me it is current job to do four shoulders...

Have a nice evening,

 

[MooreToolsPlease]

One thing that has always crossed my minds with mortice and tenon joinery is the location of the tenon.
In every photo I remember seeing of a tenon it has always been in the centre of the thickness.
does anyone ever put the tenon more to the front or back of a joint?