Sliding Sash Bow Window Repair

[meccarroll]

Hi all just thought I'd post this out of interest, it's a bow window I was asked to repair some time ago.

I have made several circular window and door frames etc but this was the first time I was asked to repair a bow window. It had been repaired before but not very well.

As you can see it had a lot of rust patches showing on the bottom rails of the sashes where someone had nailed strips of hardboard on to cover the rot before the window had a re-paint.

The first thing I did was take out the sashes for referance and make a template of the window using strips of thin plywood etc.

Here is a picture of the sashes I had to replace:

I had to be careful taking the glass out because I had been quoted £700 for each piece of glass if it needed to be replaced. They said if they had to make new curved sheets of glass they would not guarantee it would be the exact same curve.

I made an onsite template of the bow using strips of ply. This was set on a sheet of ply on the workbench and from there I made a trammel to mark out the components such as Cill, staff bead etc.

 

[Austin Branson]

Blimey! Looks like a very demanding project! Please keep us posted on progress. Best wishes.

 

[meccarroll]

Once I had drawn out the bow window and worked out the lenght of each component I attached a piece of ply to the bottom of my router to form a tramel. I fixed the ply base in the centre of the bow and then made ply templated for all of the components. Each component had a different radius so I had to adjust the ply tramel for each.


Using a router and ply base to cut the inner radius of a cill template:

I then moved the radius of the ply base to cut the outer radius of the cill template.

I placed the templates on the timber parts, marked shape of each component using the templates then bandsawed them to shape leaving enough for later machining.

The black line is what I later machined off using a spindle moulder.

 

[meccarroll]

Blimey! Looks like a very demanding project! Please keep us posted on progress. Best wishes.

It was quite a learning curve but I had done curved work before so I had some prior knowledge. It's something I did quite a long time ago but I don't think I ever posted it up on here and thought it might be of interest to some.

 

[meccarroll]

Below is a pile of components which have been roughly cut to shape on the bandsaw and are now ready for shaping on the spindle moulder:

Once the component were roughly cut to shape I pinned the templates on to the edge of the component and used the template to run along a ring fence which was set up on the spindle moulder.

A rebate block was used in the spindle moulder to first obtain the initial profile of each component.

This gave me the initial four square edges I needed to machine the moulds and rebates etc.

 

[johnnyb]

Beautiful work, what was the extent of repairs in the end? I completely replaced one last year nowhere near as curvaceous as this and that was a challenge but I found it absorbing. Mine was a mildly curved frame with straight casements!

 

[meccarroll]

Beautiful work, what was the extent of repairs in the end? I completely replaced one last year nowhere near as curvaceous as this and that was a challenge but I found it absorbing. Mine was a mildly curved frame with straight casements!

I ended up replacing three bottom sashes, repaired one top sash and replaced most of the bottom half of the window box sections, cills, staff beads etc.

I remember when I was setting out the sashes thinking do I splay the sholders or do I make them square?

 

[meccarroll]

This is a picture of me feeding the components on the spindle moulder using a template, ring fence and bonnet guard:

Ideally a holding jig with couple of holding points set well away fom the machine head would be used so Your hands can not get anywhere near to the cutters.

Something like the below jig is ideal for feeding in curved work on a spindle moulder.

 

[deema]

Great work, really appreciate you writing it up.

 

[meccarroll]

Once I had squared all of the components I could move on to the setting out and moulding. Below is a picture of a ply template running along the ring fence and a cutter moulding the curved staff bead below.

The cill sections had to be moulded differntly or at least I decided to make a cradle to hold them and slide the cill along the cradle and through fences to do the cill slopes.


A rebate block was used first to do the donkey work before changing to a whitehill block with angled cutter.

The below picture is just showing the whitehill block and cutter used to cut a 9 deg bevel on to a cill. I now have and use the much safer Vari Angle Blocks and dedicated cill blocks for this type, it is now not recommended to use the type of whitehill block below.

 

[meccarroll]

Transfaring the marks from the setting out rod required me to make a lot of jigs to hold the sections in the correct place for marking.

 

[niall Y]

You have done a great job sorting this out. Trouble is, apart from being paid for your efforts, no one will really appreciate the work you have put into it. Unlike new work, renovation, by its very nature, isn't really noticed when the work is complete. After a coat of paint it will be tidy but invisible. Folk will assume that it has always looked like that.

Though I do have to admit that its great to get stuck into a project of this kind, from time to time, as. It stops the brain from atrophying.

I think I might have run a mile because of the glass. I mean, why take that risk if you don't have to? I would probably have tried to negotiated a waver of sorts should any of it have been broken. Or at least have expected the customer to have taken care of removing it.first.

 

[Ollie78]

Great work, these are a headscratcher, I had to do a bowed 8 over 8 georgian one which needed a pair of new sashes, was a bit tricky to say the least.
I remeber the same question wether to do the tenons square or splayed, I forgot what I did now. I will have to see if I can find a picture.

 

[meccarroll]

You have done a great job sorting this out. Trouble is, apart from being paid for your efforts, no one will really appreciate the work you have put into it.

I used to like to do this sort of work I would take it on because I got a lot of satisfaction out of doing it. It was like being paid for doing something I really enjoyed doing so a win win.

I think I might have run a mile because of the glass. I mean, why take that risk if you don't have to? I would probably have tried to negotiated a waver of sorts should any of it have been broken. Or at least have expected the customer to have taken care of removing it.first.

It was part of the agreement that the customer paid for any broken glass and he was made aware of the price too. In the end no glass was broken but it's worth noting the price for reference should anyone tackle a similar job.

 

[meccarroll]

Great work, these are a headscratcher, I had to do a bowed 8 over 8 georgian one which needed a pair of new sashes, was a bit tricky to say the least.
I remeber the same question wether to do the tenons square or splayed, I forgot what I did now. I will have to see if I can find a picture.

I think what suprised me was the amount of templates and cradles I had to use. It did absorb me and I must admit I really enjoyed doing the work.

If you can find them please do add your pictures, they would be interesting to see.

 

[HOJ]

Absolute credit to you Mark, brilliant work, I do wonder what will happen in the not to distant future when people like you/us aren't around to take these jobs on.

I made a replacement Oak mullioned window last year for an 18th century house, over your way, client had been pretty much all over Norfolk and Suffolk looking for a joiner to make a replacement with no takers as it didn't work with their set up or skill base, I did give it a lot of thought as to whether to do it but in the end it saw it more as a learning curve and the satisfaction of doing it rather than the commercial value.

One question, is that an aftermarket ring fence on the Kitty, looking for one to go on my Rojeck SM, got a home made one I use at the moment.

 

[meccarroll]

I was lucky at the time when I got the job because I already had a tenon machine so could use it with cradle pieses to machine the tenons:

The meeting rail between the top and bottom sashes could not be done easily on the tenon machins so I used the bandsaw for most of the joint.

I used small template pieces the thickness of the tenons to mark out before cutting on the bandsaw.

It was not practical to cut the sholders on the bandsaw so I just used the bandsaw for the straight cuts and tookthe sholders out with the mortice machine.

Sorry about the fuzzy picture but you hopefully get the idea.

 

[meccarroll]

Absolute credit to you Mark, brilliant work, I do wonder what will happen in the not to distant future when people like you/us aren't around to take these jobs on.

I am now coming to the end of my career (Old boy now) but looking at the quality of your work I think we are in safe hands for the forseeable future.

One question, is that an aftermarket ring fence on the Kitty, looking for one to go on my Rojeck SM, got a home made one I use at the moment.

The rings came with the Kitty spindle moulder and I was/am not aware if they are aftermarket or not. I will take some photos of all of the components tomorrow and post them up for you to look at.

I made the bonnet guard out of sheet metal, I have a welder so could do a crude fabrication job...works well though!

 

[HOJ]

I am now coming to the end of my career (Old boy now)

Me and you both, get my pension next year, but doubt if I'll pack in for few years yet.

 

[johnnyb]

It does raise the question of whether this type of work will ever be anything but a labour of love in the future. Whenever I've done stuff I've always slightly regretted getting involved as it's impossible to come out on top financially with all the one off jigs etc. Cnc is making much curved work cheaper and less dangerous though.