Re-bending brass windshield channel

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Belliott3
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Re-bending brass windshield channel

Post by Belliott3 » Wed May 01, 2019 5:12 pm

I bought the brass windshield channel kit for my 1910 T, but the corner bends that are on the channels are too wide. I have a small piece of the original channel corner and it is a tighter curve. How do you go about adjusting the bend in the curve so it's tighter? Anyone with experience on the subject kindly advise me. The kit isn't cheap but required, as far as I'm concerned, when you're working on an early T and I don't want to mess it up. Thanks!


rgould1910
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Re: Re-bending brass windshield channel

Post by rgould1910 » Wed May 01, 2019 6:07 pm

Cut a piece of masonite the same shape and thickness as the window pane you will use and gradually work the setting channel around the masonite form. Be very careful and use small mallets, pliers etc anything you can to get the correct shape. It won't be perfect but you can get it so it looks OK when installed. Do not use heat, the piece will loose shape and look like a piece of wet spaghetti.
BTW the brass setting channel is made by Speedy Bill and is meant to be used on their reproduction frames. I wrote an article on how to put one together. If you're interested, send me an email and I'll try to retrieve a digital copy and sent it to you.

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Re: Re-bending brass windshield channel

Post by Belliott3 » Wed May 01, 2019 6:17 pm

Thanks, Richard, that's a good idea. How thick should the masonite be? Also, here is a picture of what the difference looks like. I'll email you for the information you have on the frames, thanks!
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Allan
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Re: Re-bending brass windshield channel

Post by Allan » Wed May 01, 2019 11:50 pm

Bill, Richard's tip about the masonite is spot on. It makes a former which will prevent the channel from collapsing inwards while setting the shape of the curve at the same time. I would go one step further and make a tool to help keep the channel from spreading while reshaping the bend. Timber is your friend, as it is softer on the brass. Cut a 1/2" wide strip from material the same thickness as the outside of the channel. Fix a strip either side of this piece with depth of the channel as your guide. This U shaped tool can be used in conjunction with the masonite former to keep the channel from distorting.
I don't know about not using heat. I would be tempted to anneal the bend before starting. Others may disagree. Certainly do not use heat while attempting the re-shaping.
Hope this helps.
Allan from down under.,

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Mark Nunn
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Re: Re-bending brass windshield channel

Post by Mark Nunn » Thu May 02, 2019 8:41 am

I agree with Allan about annealing the brass first. Once the brass has been formed to the as-purchased shape, the bending operation will have work-hardened the material. Hardened brass will have a percent elongation (ductility) of about 15%-17%. That's the amount of elongation it can survive before it breaks. You don't know how close to the maximum elongation your channels are now since you don't know the hardness of the brass before it was bent.

Anneal the bend before reshaping and that will soften it. The percent elongation will go up to around 40% before breaking. It may require more than one anneal operation to get the final shape.

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Belliott3
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Re: Re-bending brass windshield channel

Post by Belliott3 » Thu May 02, 2019 9:24 am

I know this may sound like a stupid question, but how do you go about annealing the brass? Can I use a small propane or mapp torch and how long do I hold the flame to the brass? All great ideas - thanks!


R.V.Anderson
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Re: Re-bending brass windshield channel

Post by R.V.Anderson » Thu May 02, 2019 10:44 am

Use a small propane torch and heat the brass until it just starts to glow red in a darkened room. Let it cool and you're good to go. Some quench, some don't. Personally I wouldn't, as that tends to cause some twist, which for some operations doesn't matter. Do be careful heating, as the channel is thin and will heat (and cool) VERY rapidly.


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Re: Re-bending brass windshield channel

Post by Joss » Thu May 02, 2019 12:20 pm

Agree with RV. Emphasize being careful with heating. NO MAPP gas. Quenching as said will likely cause bending. I have cut a hardwood template and inserted it when hot to keep everything straight. The brass will cool very fast.


George Andreasen
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Re: Re-bending brass windshield channel

Post by George Andreasen » Thu May 02, 2019 2:31 pm

Gentlemen, going by my long experience of annealing cartridge cases, I would heat the brass only until it turns a dark brown or black. This happens rather quickly, so be prepared to remove the heat source (torch) immediately. As you "work" the brass when shaping, it may be necessary to anneal more than once. You should plunge the heated brass in water to cool it off and hold that particular softness. Unlike steel, brass will not harden when cooled in this fashion......it simply stays in the softened state until you begin working it again.


George Andreasen
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Re: Re-bending brass windshield channel

Post by George Andreasen » Thu May 02, 2019 2:32 pm

George Andreasen wrote:
Thu May 02, 2019 2:31 pm
Gentlemen, going by my long experience of annealing cartridge cases, I would heat the brass only until it turns a dark brown or black. This happens rather quickly, so be prepared to remove the heat source (torch) immediately. As you "work" the brass when shaping, it may be necessary to anneal more than once. You should plunge the heated brass in water to cool it off and hold that particular softness. Unlike steel, brass will not harden when cooled in this fashion......it simply stays in the softened state until you begin working it again.

Note: The brass will retain its dark appearance and will have to be polished after you obtain the correct bend.


George Andreasen
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Re: Re-bending brass windshield channel

Post by George Andreasen » Thu May 02, 2019 2:33 pm

Sorry about the double post above...........I must have hit the wrong key when editing!


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Re: Re-bending brass windshield channel

Post by rgould1910 » Thu May 02, 2019 4:24 pm

Annealing brass as a general matter is a good thing. It should not be attempted on someting as thin as glass setting channel. If you are inclined to try it, do so on a
scrap or left over piece. You'll see what I mean.

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