Which size morticer chisel for glazing bars?

[kebabman]

I am thinking of using Wealden spindle cutter profile 263 http://www.wealdentool.com/acatalog/Onl ... __585.html
to produce some glazing bars for georgian style windows. I am finding the concept of scribing (with cutter 264) the vertical glazing bars hard to visualise when looking at drawings!
The 263 cutter produces a 13mm wide (or should that be deep) flat piece, (not sure of the technical term!), on the ovolo moulding through which I should be morticing. Should I produce a tenon the whole 13mm wide or should it be narrower. It would be even more work but is it better if the tenon is haunched?
I have taken on board the advice on this forum to buy decent morticer chisels so I would be very grateful if people could advise so as to avoid an expensive incorrect purchase.

Many thanks

 

[Jacob]

1/2".
For a vertically hung sash the mortices go through the vertical bars and are wedged through the top and bottom rails, so the vertical g bars stay in one piece. The horizontals are all cut with stub tenons.
A side hung casement has them the other way around.
It's about taking the strain, structure etc.

 

[Phil Pascoe]

Surely vertically hung and side hung would be the same thing?
It would be better to say top or side - or horizontally or vertically?

 

[kebabman]

I didn't explain myself very well. I am unsure about the point at where the vertical and horizontal glazing bars cross on a georgian style window and there is little wood to play with rather than where the bar goes into the casement frame. The 13mm "flat" from the ovolo will obviously be the same in both areas.

 

[Jacob]

I didn't explain myself very well. I am unsure about the point at where the vertical and horizontal glazing bars cross on a georgian style window and there is little wood to play with rather than where the bar goes into the casement frame. The 13mm "flat" from the ovolo will obviously be the same in both areas.

Not sure what you are unsure about! Where glazing bars cross, one has a mortice and the other is separated and meets as two stub tenons in the mortice, and scribed moulding/rebate.

Surely vertically hung and side hung would be the same thing?
It would be better to say top or side - or horizontally or vertically?

The glazing bars take some of the strain, vertically with a sash , horizontally with a casement, and are done through in one piece accordingly.

 

[kebabman]

I am unsure whether to make a mortice across the full 13mm of the 13mm flat of the ovolo.
Edit I have just found this thread with a drawing that explains it to me.
georgian-glazing-bars-t42385.html

 

[ColeyS1]

Half inch ;-)

 

[kebabman]

Many thanks for the photos. As I said earlier I find drawings very hard to visualise.
The top end of the glazing bar at the top of the second picture explains it for me, many thanks!

 

[Jacob]

Photos spot on. Forget haunches. The easy way is to make all the bars as though running through. So a common 6 pane light would have three bars, two vertical and one horizontal. Then cut and scribe the horizontal one into three short ones with stub tenons at each end.

 

[kebabman]

Many thanks for all the replies.
I have just ordered two good quality chisels so I won't be able to afford to eat for the next few weeks!