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Old 04-03-2011, 02:48 AM
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kenb kenb is offline
MetalShaper of the Month Aug. '09 & Mar. '11 Rest In Peace Ken 1960-2011
 
Join Date: May 2009
Location: Flamborough, Ontario, Canada
Posts: 418
Default More on Thickness vs Circumference

Hi Guys,

I thought I'd show you a couple of pictures I have around that do a very good job of illustrating the thickening process that occurs when shrinking the edges of metal sheet.

This part is the day cabin for my PT Boat project, and it was created from flat sheet (3003 aluminum, .063" thick) by shrinking the corners again and again until it assumed the shape of a box. This task took several annealings along the way to prevent the aluminum from breaking up.

Here's it is after starting to tuck shrink the corners in exactly the same way as I described the shrinking process earlier in this thread. Basically, you are just looking at a round bowl with square corners on it, where the shrinking effort has been concentrated into four specific areas instead of being equally distributed around the perimeter.




Here it is again after being raised all the way up. Note how much smaller the circumference of the original outside edge is now, and also observe where all the extra material ended up. The aluminum in the shrink areas in the corners has swelled up from .063" all the way up to .120" in some places, almost double the thickness of the original source material.




You'll never see these extremes in thickness when working with CRS, but the concept is pretty much the same with both materials.

I'll get to work taking some pictures of the stump shrinking process when I have a couple of days off early in the week. Then I'll post a few words about tuck shrinking with a stump.

In the meantime, feel free to chime in with any questions, comments, or additional details that you feel would benefit the discussion. I only ask that you keep the conversation focused on tuck shrinking methods only, with a view to coaching newcomers to the craft.

Ken
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Last edited by kenb; 04-04-2011 at 02:08 AM.
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