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Senior Member 4 Gold Stars
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Discussion Starter · #1 ·
How far can a piece of sheet metal be contoured? Is there a point where you have to cut and weld to make a turn? Example: making say a fender end on a 37 Chevy pickup rear fender. They are pretty much a tear drop shape. I wondered if it would have to be made in two halves and then welded together to get the compound curves?
I'm not working on anything like this, but it did make me think from time to time.

1,297 Posts
Hi Mikekt55
WOW you get an A for that question.:eek:

First question: How for can a piece of metal be contoured?

This is a typical bowl shape out of one piece

it could be quite a bit deeper. there is still quite a bit of material left to be shaped. Now most concerns would be thinning but is rarely a problem even for a bowl shape . The time it come to be a problem is when you attempt to go to deep you will thin the deep area and will be thickening the out side or shallow. At this point you have to decide how many pieces would be best to shape this from.
There is also the product to consider ( quality of steel ) which not to get long winded as I do all to often If its steel you are shaping the best seems to be 1008 - 1012 series. CRS . which is cold rolled steel. This is great for shaping and can take lots of shape before it fatigues.
Now when it comes to Aluminum 3003 h14 is the choice and will also shape nicely .
Both products can also be annealed drawing the carbon and softening them .

Second question: compound curves These are the tough even for seasoned metalshapers.
most times when compound are tight and many you are far better to make these panels in predetermined pieces.
Mild compounds are tricky at best but can be achieved with a watch full eye on both curves. the problem you run into is when shaping the second curve (compound) it will change the shape of the first curve so you have to track back and forth correcting between . I will make some samples and show the areas you would be concerned with , now this most the time will pertain to one shape as different situations or shapes will react different . But each time you make a shape it gives you a new technique to use on the next one.
Hope this helped , I will address each questions with samples and hope this give gives you a better idea how to approach a future project or even a current one.
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