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Tiger
12th July 2007, 10:20 AM
I'm looking at using some beading on the outside of some windows to hold glass in (rather than putty). Had a look at a friend's, I couldn't work out what angle to cut the strips. They're not 45 degs, some type of compound angle I guess. What sort of angle should I use for a neat joint? Thought a coping joint might be the go but a bit confused when I saw what was on my friend's window.

joe greiner
12th July 2007, 01:33 PM
Are we talking about quarter-round moulding? Sometimes not exactly symmetrical, i.e. more like a quarter ellipse. If improperly installed, an awkward miter would be required. If you mark one back face before cutting to length, you can keep proper orientation all around and use a regular 45 degree miter.

Joe

Tiger
12th July 2007, 04:48 PM
Joe, the stuff that I've seen is not rounded but bevelled outwards, I guess to provide water run-off.

joe greiner
12th July 2007, 10:45 PM
OK, Tiger. But if the same cross section is used all around, an awkward miter should be needed only if the cross section has unequal leg lengths, and one or more pieces is installed barse ackwards. The trick of marking the back face before cutting should still permit 45 degree miters. If you're using different cross sections for top, sides and bottom, or if one or more pieces is deliberately set awry, an entirely different situation. Only the bottom piece would need a water-shedding bevel, and a film of sealant under all pieces is advisable. Perhaps a pic of your friend's installation would illuminate things.

Joe

Tool-Horder
12th July 2007, 11:46 PM
I'm looking at using some beading on the outside of some windows to hold glass in (rather than putty). Had a look at a friend's, I couldn't work out what angle to cut the strips. They're not 45 degs, some type of compound angle I guess. What sort of angle should I use for a neat joint? Thought a coping joint might be the go but a bit confused when I saw what was on my friend's window.


Your not the only one confused. :? Not totally clear on what you are asking so I will answer all possibilities.

Sound to me like you are 'replacing' the putty with a timber bead insert and a bit of silicone.

Assuming you are asking about the angle of the face of the insert, that will be determined by your window sash.
Lets say
Rebate in sash is 8mm wide.
Glass is 3mm thick.
Glass rebate in sash is 15mm deep

....(15 - 3 = 12mm. Cross section of bead would be right angle triangle with 8mm base and 12mm high. (although you would probably leave a small flat on top) A little maths and you come out with an angle of 56.3*. Or if you want to do it the easy way draw up the triangle ( measurements scaled up by a factor by 10 for ease of drawing) and measure angle.

A coped joint is the 'standard' for most structural joinery. Since you are working with a triangle mould the cope could be easily cut on drop saw. It would be a simple angle and not a compound angle. It would simply be the complementry angle to the face of the mould. ( 90 - 56.31 = 33.69*) A coped joint would look like it was mitred if fitted properly

The only time a mitre joint will vary from 45* is if you are fitting out an irregular shaped frame like a rhomboid / octagon/ triangle.

Hopefully that helps to clear it up ... or confuse you more :?

johnc
12th July 2007, 11:58 PM
Tiger,

I've recently cut some beading to match some damaged stuff on a Stegbar window. I used a 15 degree router bit and ran a bit of sand paper over the piece to slightly round and relieve the edges. Seemed to match well enough and I hope this goes someway to answer your question.

Cheers, John.

Tiger
13th July 2007, 09:23 AM
Thanks, guys, you may have given me what I need. If still a problem, I will get a photo for you.