U Channel windshield molding

What is the small radius like? Annealed brass can be bent quite good, especialy if you keep it hot while bending (it work hardens quite fast). I would make a jig out of 1/4 thick sheet steel (cut to shape, of course) and bend the frame around the jig.

Nick

You might try using Sil-Phos (or any of the other names it goes by). It's what refrigeration guys use to braze copper tubing together. It's mostly copper with 5-10% silver and a small amount of phosphorus to make it self fluxing on copper. You'll need to use a high temperature silver solder flux for the brass despite the self fluxing nature on copper. I'm not positive it'll work though since it might be a little high temperature for the brass. I know I had problems the one time I tried to use it on a brass fitting but I didn't have any flux with me at the time.

Wayne Cook Shamrock, TX

Small radius on the "90 degree" bend is 1"

Tried heating and simply bending the channel around a 1/4 plate steel template, but it just buckled along the sides of the "u" and the bottom of the "u" kinda buckled inwards into a concave shape along the bend. I was hoping the heating and bending would work but was very disappointed with the attempt. Ken.

I'm not familiar with this, but will check it out. I'm assuming (maybe mistakenly) that this is a solder - but you used the term "braze" in the following sentence....

Can this be done with a heavy soldering iron - or is it torch only??

Ken.

This is something I hadn't thought of... and also something I've never done before. . . not exactly sure how I would go about it. The bottom of the "u" channel is about 1/8 thick and is fairly stout. Bending by hand, with heat applied only produced a wrinkled mess - . Ken.

What about bending the brass first, then take the high spots down, then cut the channel?

Seems to me trying to bend the two uprights on the channel the hard way is always going to cause more mischief than cutting the slot on an irregular curve. You might be able to accomplish this with some finger saving wood fixtures and a router bit. If cutting the slot in the tight inside curves are a problem, perhaps you can mill off a section of the upright and finish the slot on the mill and then just make up a cover plate you can solder on.

Another idea would be to cut two sets of uprights out of 1/16" thick sheet stock, and then cut the center section out of 1/4" sheet. Then you could pin them or jig them and solder them together.

If you take the second route, you might want to make the pieces a little large and then finish the whole assembly to size.

You might be able to get some scrap graphite from an edm shop to use in making your soldering fixture so the solder will not stick to the fixture.

Here's a thought.. Cut the actual shape of the front and back parts of the channel from sheet brass. cut the third side as a strip, shape to fit the contour and solder/braze the three together. Clean up edges with a file. Could be cut with a scroll saw accurately.

It's applied at a red heat so the temperature is high enough to put it in the braze category.

Nope. A soldering iron won't even come close to getting it hot enough. That's why I said I'm not positive it'll work. It may melt to close or even above the melting temperature of brass. It's great for copper but brass I'm not as sure about. I've had mixed results with my attempts to use it on brass so you may have to try it and see.

Wayne Cook Shamrock, TX

Would go along with that. Silver solder, "Eziflo", and the proper flux would work. Everything needs to fit accurately before soldering as this stuff does not fill gaps. A few locating pins would help. Preheat the whole assembly with a nuetral flame until the flux melts and then flow the solder into the joins. Do it properly and only a small amount of solder is needed.

The most suitable method would depend on how many you need to make. The issue you have is shrinking of the sidewalls around bends. This can be done in a number of ways. It could be hammerformed on a jig -- labor intensive but it works well for one-offs by a metal artisan. A skilled worker might be able to make them with an inside jigplate and an English Wheel to shape/shrink the sidewalls.

Saw kerfscan be filled with a bridging alloy as Bridge-it or Barricade. Color match won't be perfect or even good, but you could separate the color match issue from the forming issue by plating after forming. Kerf it, form it, jig it, fill the gaps, grind the outside edges smooth, brass-plate it for color. Send it out or do it yerself. Caswell Plating offers brass plating.

But you can hammer the buckles flat. While still in the template and heated.

What temperature did you hve? Was it glowing?

Nick

Ken, Maybe this seems crazy to you but how about sawing the shape out of plate and milling the groove? I just did this for a 1/2" thick piece of glass for a fancy shower. The brass was 3/4" thick. I did this on a CNC mill though. Eric

Update on u channel bending.... Starting to get a little success.... Wasn't using "enough" heat. Thanks for all the tips and suggestions..... Sometimes wonder how we get into these messes.... Ken.