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Discussion Starter #1
My '81 GL500 has the beginning of a tailpiece made from a cut-up Harley fuel tank, pictured below. I want to bend the leading edge of the steel downward/inward about 90 degrees so it points inward toward the frame centerline all the way around the leading edge. The goal is to have a flat mounting surface around the leading edge of this tailpiece so I can rivet a vertical plate to it and complete the tailpiece, as well as to decrease the overall length of the tailpiece itself to give more room for the seat.
I am no good at advanced metalworking stuff like this and could use some help - how can I bend the edge of a curved piece of steel so that it looks clean and not wrinkled?

Here is what I've got:
mine.jpg

I want to end up with something like this:
meyerbuilt cb550 tailpiece.jpg
 

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You could cut small notches around the edge, bend the 'flaps' inwards slightly, then use a body repair dolly on the inside and tapping with a peening hammer to shape it. You'd have to weld it up and grind a bit when done, but the result might be acceptable.
 

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Hello

You will need something like that. 1083.jpg

To bent the steel for a round 90° angle: It allways will wrinkle. You have to make cuts or to cut away small triangles. Hammer the edge with the right hand tool of the sortiment on the picture.
The hammer is one the outside, the tool is on the backside. Sometimes You have to change... to hammer from the inside....and so on
You'll get a feeling and You hear it what is right.

A little help could be: To weld a round steel rod (diameter 6 to 10mm) into the backside to get the shape of the wanted edge / form. Then do it as I wrote before.
All this work goes better hot. A torch fired with Butan/Propan (or acetylene / oxygen torch) will help.
After the work is done: Close the cuts with weld.
(But the next problem arrives immediately: The welding seam will rust in a very short time. The inside of the tailpiece I would coat with tin. (torch, flux and tin.)) The outside ?? I read You want to get the bare metal/steel finish. (2 component varnish ?? )

Try it. After some month and Years it will make fun to make edges more difficil/difficult/meticulous :)

Gruesse
WolFgang
 

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It depends on what the metal is, and since its an old tank I will assume its sheet steel, proabably 18 or 20 guage. Unless you have a TIG welder, you will have to "shape" the metal by hand, which is very doable but WILL take a long time and the right tools. Wolfgang above has the best idea, either get a set like this or "collect" tools you can use. You will need to go slow and take your time, and basically do the following.

- You will need a set of pliers (T nose ones used for bending sheet metal would be the best, but regular ones will work if you take your time and do it in small increments) and start to bend the flat sections in a bit .... JUST A BIT.
- You will need some form of curved "backer block" (like the curved steel ones shown in the kit above) to hole in the corners while tapping the metal down. The key is to tap slowly as to not make a crease, you want to "stretch" the metal, not have it crease of fold.
- You need to repeat this until you get it where you want it, paying close attension to the corners (as thats where it will crease and buckle if you go too fast).

My best guess would be with the right tools it would take probably 20 or so man hours to do it, which while it seems like a lot really isnt. Most places that do this sort of work use either a form press or a collection of tools (english wheel, power hammer, "torch and tap") to get a shape fairly fast (but they have also being doing it for many many years).

Again, its doable, but will take some skill and a lot of time. Easiest way is the standard cut/weld/pound/cut/weld/grind method, which can be done is a few hours, but then again requires skills and welders.
 

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Discussion Starter #5
Thanks for the advice, fellas.
I was afraid that might be the only option - I have a lot to learn (and practice) about metalworking before I attempt something like that. Looks like it's time to get some donor materials!
 
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