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Old 11-08-2017, 03:15 PM
crystallographic crystallographic is offline
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Location: Western Sierra Nevadas, Badger Hill, CA
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Quote:
Originally Posted by WCRiot View Post
Guys
I am trying to build new corners for the rain water channel for the inside of the trunk. See the yellow arrows in an example picture

This is a C or U Channel, but I am starting with an L. I figure i can always weld the wall on and covert the L to a C/U.
As another example image, I am trying to achieve this:



When i shrink i start to get pretty good movement. But with only shrink on this side I can only get so far. This picture is in process so I am able to get more radius to the bend than what is shown, but not much more.


So last night i tried switching to the streching die and hitting the other side. Thinking that i have done all the shrinking i can. Maybe stretching will help push the metal more to form that "C" shaped radius (from a top view). Is this the correct approach?


The problem i see is that when i stretch, instead of the metal following the contour that formed from shrinking, the side of metal being stretched fans outwards. Create a fan or sea shell shape.

I used a different piece of sheetmetal to help illustrate what the stretching die does.


I will watch some youtube videos to try and learn how to achieve the shape i need, but wanted to get some advice from those on here.
Hi WC,
Kerry and I are seeing that your shrink is going well until:
1) your metal gets hard
and
2) your metal gets thick.

You can also shrink when the metal is hot. Heat until it is past purple/blue and goes "black" then shrink 2 or 3 times, and then spray the jaws with alcohol to cool them (no rust).
You will find you can get more shrinking for longer if you do this, and the metal will not crack ..... at least not for me.
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"All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919.
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