Sash bar dimensions for historical windows

[Phill05]

Now if I could just persuade you to come round and give a practical demonstration....
Thanks Jacob!

Really that's far and away beyond my comfort zone. I'll leave that to the experts.

You should use molding / foundry sand to cast into as the heat hardens the mold/sand to reuse it, builders sand will loosen when dry, these are some old style sash weights I used to make, the mold box was made in two parts so I could put the wire hook wrap in the middle of the weight block they were made 20" long by 2" by 1 1/2" with a hook at each end so I could cut different lengths out to suite what the window needed, in the image you can see the parting line of the box in the lead, also you can see how the hook was placed.



In this second image these rounds I made to use on the bench for holding down timber whilst using the plane or holding down glued items.



I still use different sash weights as test weights on longcase clocks.

 

[Jacob]

Have to disagree there about how much is lost from sawn stock. As a timber retailer pre-decimal sizes, 2 x 1 sawn would lose an 1/8th in machining on both dimensions, 4 x 1 would finish at 3 7/8 x 7/8, approx 98mm x 22mm.

Yes but only for very, very straight stock and/or short lengths

Post decimal, stock sizes were 25mm thick finished to 22mm width finish was about 3mm less than sawn size, so a nominal 6" board in metric was 150mm which would finish about 147 ish.

I used to buy a lot of Swedish redwood and it seemed to stick to imperial inch sizes, sometimes if lucky a smidgin more and you'd get a 26mm sawn board

The likes of B& ? started selling timber to even more reduced sizes, hence what was once 1" nominal and 7/8" finish now comes out at 20mm if you are lucky. Tree wood ain't what it used to be.

Yards near me used to stock a lot of PAR from full lengths up to 5.1m and ex 4x1" would often come out as 96x19 if you were lucky, and shaped like a propellor!

Once asked the rep what was the difference between PAR and PAR select and he gave me all the spiel about not having so many knots and shakes in the Select, to which I replied, No, PAR is twisted when you get it, PAR Select twists when you finish the job. We had a lot of twisted stock uplifted and replaced!

Spot on!

 

[Jacob]

You should use molding / foundry sand to cast into as the heat hardens the mold/sand to reuse it, builders sand will loosen when dry,

Builders soft sand easy to come by and sets to some extent but breaks up easily. Yes a mould might only be usable once but it only takes a few minutes to do it again if you keep your pattern handy

these are some old style sash weights I used to make, the mold box was made in two parts so I could put the wire hook wrap in the middle of the weight block they were made 20" long by 2" by 1 1/2" with a hook at each end so I could cut different lengths out to suite what the window needed, in the image you can see the parting line of the box in the lead, also you can see how the hook was placed.

Parting line? I just poured lead into an open impression of the pattern and no parting involved. Sounds like mine were a bit more ad hoc than yours. Also I'd saw and drill for the hole. More like 1 1/2" to 1 3/4" square, 2" a bit on the big side.

In this second image these rounds I made to use on the bench for holding down timber whilst using the plane or holding down glued items.

I do same with bean tins full of lead melted in. Really handy to have. About 3.5 kg. "Gravity clamps". It's useful to have a lot for some jobs like sticking down formica, and I always save any lead scraps which come my way

 

[Jacob]

I reason any post can have the most enlightening information and it could come from anyone. it's not about the right way or my way it's about assessing what someone's saying right or wrong. the rod storey board etc is interesting because Mr butler has provoked people to expand on there methods(unintended no doubt)
in real detail(thank you sgian et al)
which has value in its self. many posts here attract zero interest or argument and that is the real problem.

Yes it's just nattering on about how to do things and you never know what might usefully turn up!
Wondering about the rod and full sized drawing discussions - maybe it's because people aren't too familiar with drawing board techniques?
It is another thing you have to get to grips with and may not have done it at school, I didn't myself. Easy to take for granted.

 

[steve355]

A practical window question….

I have completed my frame now (at last) and I’ll start on the sash tomorrow morning. I will have to do some haunched m&t joints, obviously,

The question is, how does one actually cut the haunch directly next to the tenon? Can’t get a saw in there, can’t get a router in there… is it just a case of getting in there with a chisel and taking it out carefully?

 

[Jacob]

This is "franking", a peculiar atypical joint, a reversed haunch, not normal at all.
It is in Ellis, along with a lot of other really tricky joints, best approached with caution, as the simpler alternatives are much more common, easier to construct and perform perfectly well.
I blame the book.
I'll see if I can dig out a picture later.

 

[steve355]

This is "franking", a peculiar atypical joint, a reversed haunch, not normal at all.
It is in Ellis, along with a lot of other really tricky joints, best approached with caution, as the simpler alternatives are much more common, easier to construct and perform perfectly well.
I blame the book.
I'll see if I can dig out a picture later.

Ah I see… the standard form of the haunched joint having the “haunch” sticking out part adjacent to the tenon.

By the way, what clearance gap would you suggest between the sash and the frame? I’m actually just drawing it up now.

 

[Jacob]

Ah I see… the standard form of the haunched joint having the “haunch” sticking out part adjacent to the tenon.

Yes, and as far as I can see a much better joint.
I wonder whether some of the "hi spec" detailing is just showing off for commercial purposes, like your glazing bar detail somewhere earlier in this thread - not traditional at all and perhaps with machinery playing a bigger part

By the way, what clearance gap would you suggest between the sash and the frame? I’m actually just drawing it up now.

2 to 3 mm ish. Less is probably better as you can always take a bit off if it's a tight fit.

 

[steve355]

Yes, and as far as I can see a much better joint.
I wonder whether some of the "hi spec" detailing is just showing off for commercial purposes, like the glazing bar detail somewhere earlier in this thread - not traditional at all.

2 to 3 mm ish. Less is probably better as you can always take a bit off if it's a tight fit.

Thanks!

 

[johnnyb]

having less material removed from stile is the thinking behind this joint. as sashes reduced the margins of strength became sub optimal. one joint or the other is mostly a learning experience. if its a reasonable size it's not going to be under huge stress unless it's double glazed. what I would say this illustrates is some freedom of thought being exercised by the old boys. like my mason carving pineapples by rack othe eye it makes little difference to a highly skilled man which way its made. there up to it.

 

[Jacob]

having less material removed from stile is the thinking behind this joint. as sashes reduced the margins of strength became sub optimal. one joint or the other is mostly a learning experience. if its a reasonable size it's not going to be under huge stress unless it's double glazed. what I would say this illustrates is some freedom of thought being exercised by the old boys. like my mason carving pineapples by rack othe eye it makes little difference to a highly skilled man which way its made. there up to it.

All I know is that I've never seen it done on any of the old windows I've taken out, nor a failed normal haunched M&T - except when everything else is failing too, of course.
PS come to think I have seen failing M&Ts where the problem has been the peg. They get fitted by hammering a squarish split peg into a round hole drilled through, which means they get tapered as they go. I've found them part emerged from their holes and can only account for this as some sort of ratchet action when paint has failed and the woodwork is getting alternately wet and dry, expanding and shrinking. They come out opposite way they were hammered in.

 

[johnnyb]

a classic failure would be at the meeting rail. often big old windows had dovetails here to counteract the stress of opening a "stuck" sash. yes much common work was far less ambitious both in size and scope.

 

[johnnyb]

rod of a folding chair stool I'm making. it's important here because it has a mechanism that must work.
albeit extremely simple! the holes are from another job in fact the mdf is a air press platen!

 

[steve355]

A wooden rod. One disadvantage I’m finding of MDF is it is hard and slippery and doesn’t like dividers etc.

 

[HOJ]

The question is, how does one actually cut the haunch directly next to the tenon? Can’t get a saw in there, can’t get a router in there… is it just a case of getting in there with a chisel and taking it out carefully?

Not sure I understand your description, a haunch to me is a reduced part of a tenon, if you are trying connect a rail to a stile with a moulding I call that a cope and stick joint.

Pictures sometimes help:



On this joint the tenon has a haunch and the moulding's are "coped and stuck", the result being:



Alternatively I use a scribed haunched tenon joint:



The later is a fairly simple job when you have one these at the back of the shop:



With regards using rods for square/rectangular windows, I don't see the need, I'm in the middle of making 10 Oak windows, everyone is a different size, moulding's and profiles are the same, so all I need to know is how big is the hole they need to fit into.

 

[Jacob]

........With regards using rods for square/rectangular windows, I don't see the need, I'm in the middle of making 10 Oak windows, everyone is a different size, moulding's and profiles are the same, so all I need to know is how big is the hole they need to fit into.

Yes it's possible to work without one on simple stuff like that, but I'd still use a rod; probably consist of a drawing showing the cill and bottom rail details but with marks for each of the different sizes and positions of the head and the top rails, if there's enough room on the board. And ditto for the width.
It's just a record of all the measurements and is better there in one place rather than on a piece of paper with lots of workings out etc.
You can do two things with the rod; see exactly how things fit together and take marks off by laying components on, without any further measurement.
What is that thing at the back of the shop? Maybe thats the game changer?

 

[mouldy plane]

Not sure I understand your description, a haunch to me is a reduced part of a tenon, if you are trying connect a rail to a stile with a moulding I call that a cope and stick joint.

Pictures sometimes help:

View attachment 165755

On this joint the tenon has a haunch and the moulding's are "coped and stuck", the result being:

View attachment 165756

Alternatively I use a scribed haunched tenon joint:

View attachment 165757

The later is a fairly simple job when you have one these at the back of the shop:

View attachment 165758

With regards using rods for square/rectangular windows, I don't see the need, I'm in the middle of making 10 Oak windows, everyone is a different size, moulding's and profiles are the same, so all I need to know is how big is the hole they need to fit into.

View attachment 165759

Thank goodness! common sense prevails at last. Hight, width, depth of reveal. What else do you require, sod all if you have done it all before.

 

[Jacob]

Thank goodness! common sense prevails at last. Hight, width, depth of reveal. What else do you require, sod all if you have done it all before.

You also need the position of these details along your rail/stile etc.
A common trad sash with 3x4panes could have 30 or more components.

 

[steve355]

Thank goodness! common sense prevails at last. Hight, width, depth of reveal. What else do you require, sod all if you have done it all before.

As Jacob pointed out the picture I shared above was actually a “franked” tenon. t has a “negative haunch”. All of the joinery books circa 1900 show this as the main joint for window sashes. I was asking if there was a method to cutting it as it wasn’t immediately obviously to me.

 

[Jacob]

It's a trendy detail in 1900 it seems, but not at all common in earlier stuff, and not easy to cut out except with a mortice machine.