Window board for a round window

greentower

Hi
I am looking for some advice please
I have a round window which is 125cm in diameter
The inside skimmed Window recess is 21cm wide

I would like a wooden window board ideally white oak (as all skirting and doors are white oak)
The window board would be 31cm wide at the bottom, tapering in to 24cm at the ends
The board would be less than a semi circle closer to 1/3 of a circle

So far the best option I have come across is laminating
Using thin boards or plywood, bending them and gluing them together one at a time

I am really trying to find out what is possible and what the approximate cost will be

Thanks

galwaydude18

greentower wrote: »

Hi
I am looking for some advice please
I have a round window which is 125cm in diameter
The inside skimmed Window recess is 21cm wide

I would like a wooden window board ideally white oak (as all skirting and doors are white oak)
The window board would be 31cm wide at the bottom, tapering in to 24cm at the ends
The board would be less than a semi circle closer to 1/3 of a circle

So far the best option I have come across is laminating
Using thin boards or plywood, bending them and gluing them together one at a time

I am really trying to find out what is possible and what the approximate cost will be

Thanks

Post up a pic of where it is going

greentower

Sorry, I am not allowed to attach files until I have 50 posts :-(

galwaydude18

greentower wrote: »

Sorry, I am not allowed to attach files until I have 50 posts :-(

Pm sent

Jimmy_M

you could do it in three or 4 separate sections. you just need to cut the right angle on the wood and either join them or butt them.
I did it for the boarder on a curved deck i built.
Took me a long time to get it right on paper (chippies would be used to this kind of thing id imagine)- but i think the calculation for the angle to cut each end of timber was something like;
the angle the entire curve goes through divided by number of joints divided by 2....

Using formulaes for arcs then you can work out how wide your plank needs to be to cut the right right curve into it.

You kind of need to know the centre point of the circle too (in my case it was easy because i dictated that - but yours is there already)

recipio

greentower wrote: »

Hi
I am looking for some advice please
I have a round window which is 125cm in diameter
The inside skimmed Window recess is 21cm wide

I would like a wooden window board ideally white oak (as all skirting and doors are white oak)
The window board would be 31cm wide at the bottom, tapering in to 24cm at the ends
The board would be less than a semi circle closer to 1/3 of a circle

So far the best option I have come across is laminating
Using thin boards or plywood, bending them and gluing them together one at a time

I am really trying to find out what is possible and what the approximate cost will be

Thanks

I think what you want is a portion of a circle ? You don't say if you want to do it yourself or have it made. I would think you are right, the easiest way is to laminate the whole thing.
Making a former to the correct radius is tricky and you need a male/female form to be clamped together unless you have a vacuum veneer bag.
Its a job for a well equipped workshop.

kadman

Probably the simplest for you is the method you already mentioned. Laminating.

If I am reading this correctly, then what you want to do is make a board that covers part of the reveal?

If I am right here, then you wont need to construct any former, just laminate the board in situ, and use the
existing finished ope as the former.

kadman

kadman

Here is the window in question, I have no doubt the forum will suggest the best method for the window board.

kadman

tabby aspreme

What thickness do you want the finished board to be? It would be difficult to laminate in situ with the 100 mm overhang at the bottom of the window , a single former and a few wide ratchet straps would probably be sufficient to hold the laminate strips in place while gluing provided a slow setting glue such as cascamite was used to allow time to get everything into place. Another option would be to fix strips of wood 30 to 40 mm wide side by side facing outward to the required width similar to barrel staves and cover with 3 mm oak veneer ply or 3 mm solid, then face with another strip of solid timber, veneered ply could be the better option here as a piece of solid oak 31 cm wide may not be happy glued to pieces at a right angle to it due to different rates of movement especially if the window gets direct sunlight.

Jimmy_M

ohhhh i was miles off - i thought it was circular on the x and y plane. not z

recipio

tabby aspreme wrote: »

What thickness do you want the finished board to be? It would be difficult to laminate in situ with the 100 mm overhang at the bottom of the window , a single former and a few wide ratchet straps would probably be sufficient to hold the laminate strips in place while gluing provided a slow setting glue such as cascamite was used to allow time to get everything into place. Another option would be to fix strips of wood 30 to 40 mm wide side by side facing outward to the required width similar to barrel staves and cover with 3 mm oak veneer ply or 3 mm solid, then face with another strip of solid timber, veneered ply could be the better option here as a piece of solid oak 31 cm wide may not be happy glued to pieces at a right angle to it due to different rates of movement especially if the window gets direct sunlight.

Its a big job to make a proper former for lamination. I think I would just make a frame with three arcs of the correct radius ( 62.5 cms ) and construct a coopered portion of a circle in oak - a bit like wine barrel except the staves can be parallel. The faceted joints can be sanded out with such a large radius.

greentower

Thanks for all of the replies guys, I will look at the different options, thanks again

kadman

You don,t have to construct any former at all, you,ve already got one, its the base where the window board is sitting on.

As you will be fixing the board when its in place , it will be held true to form after laminating.

You are constructing in a complete circle form, so once your laminates are in place , you can place pressure sticks from the top of the window downwards towards the laminated board , and have them bent when placed in to put pressure on the board. These are your clamps.

Please don get bogged down thinking of coopering/ ect, clearly as you wont be.
Coopered staves in this instance would have the grain running from the window frame outwards towards you.

You can laminate and use bendable plywood if you want to, and top laminate that with the grain of your choice. But its well doable with solids .

Just to see whats best for you, whats your skilset and what tools do you have , and that will give the posters a better chance to choose the easy route for you.

kadman

woodturner

Just as Kadman has suggested. Couldn't have been explained any better.

kadman

woodturner wrote: »

Just as Kadman has suggested. Couldn't have been explained any better.

I thought you would, I was actually going to ask you to explain it, as I thought you,d hit the mark as well:)

Or if he doesn,t want to use sticks, set up the laminations on a bench, and wrap a good web ratchet around them lengthwise, and crank away, until you can fit them into the curve.

Or scribe out the circle radius on a 22mm mdf sheet, and cut , lets say a 3" wide piece, like curved architrave. 2 please.
Groove each one along the curve, the thickness of the window board, say 8 mm deep.
Glue the laminates, curve with a ratchet strap, and pop the grooved mdf on, to act as a former. Leave til cooked:p

woodturner

Don't know if you got this done yet but if you're anywhere local I can get the solid oak for you and have it drum sanded down to 3mm.

recipio

I've done a bit of lamination, mainly for small table legs. Whatever method you use it has to be clamped very tightly otherwise you get annoying voids between the layers. I don't think using clamping sticks would work for that reason.
Nothing beats using a former. In a workshop I would make a convex former to a radius of 62.5 cms and clamp the plywood ( top layer can be oak veneered ) in a vacuum veneer bag.

kadman

Lots of good ideas here, surely one that fits the bill, budget,skilset,workshop access ect.

good luck.

kadman