New/old steel body panels

Hey, don't be sorry. Look at this as an opportunity. d8-)

I'm really curious about it. Making a body-panel die of the right shape, more or less, that will last through a short run, more or less, has been done for at least 50 or 60 years, using Kirksite and epoxy. Making precision replacement panels, especially ones that can fit together reasonably into a complete car, like the ones described in that NYT article, is something else again. As you mentioned, getting the springback right, and all the flanges and so on is not the same thing as whacking out the basic shape.

I'll see what I can find out. Maybe after the holidays.

-- Ed Huntress

Reply to
Ed Huntress
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Could you use an original panel to get most of the bulk in Kirksite and then tune the punch from there? PU for the die block.

Or even, use that as a pre-form and then wheeling machine from there...

Kirksite has the advantage that once you've done the limited run you can just put it back in the crucible...

Mark Rand RTFM

Reply to
Mark Rand

I don't know. Shrinkage of the Kirksite might be a problem. I forget its characteristics.

It's been handy material for a very long time, for short-run and prototype work.

-- Ed Huntress

Reply to
Ed Huntress

One method for low production (but still production) draw dies is sheet hydroforming. The female die cavity is the master form, and fluid is used instead of a punch. Slower than hard draw dies (something like 1-2min/draw, instead of 5sec or so) but mucho cheaper I'm sure. Many of the panels on the Pontiac Solstice are made this way, IIRC.

First hit on Google:

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I'm sure there is a fair amount of rework required after the initail draw. Many style lines are either not in the draw, or the rad is much larger than the finished panel because such tight rads are impossible on the first operation (panel tears instead of flowing over the rads).

**Perhaps this doesn't apply if they're using hydroforming...

It will certainly be interesting to see what Ed digs up. This is entirely another world for me.

Regards,

Robin

Reply to
Robin S.

That's why they hydroform the Solstice panels. They're too extreme for conventional closed-die stamping.

Be patient. I have several jobs in the queue, and this smells like a job for which it might be hard to get people to talk.

-- Ed Huntress

Reply to
Ed Huntress

I could name you a product. But then with your OT, I don't think I can justify the 5 minutes to walk through my linklist. You've already wasted enough of my time.

Nick

Reply to
Nick Mueller

If you're worried about your time, why did you bother to type a message?

I think you mostly wast your own time, Nick. And if you aren't even going to tell us about the product you're thinking of, you're now wasting ours.

-- Ed Huntress

Reply to
Ed Huntress

I've only installed one of these, the radiator support (entire front cross panel) for a Ranger. It fit OK but not perfectly and had some wrinkling. I got the impression that Veng's supplier had used an original for a model and ignored springback.

These parts are installed one at a time by people with the skill and tools to make them fit, often on vehicles with other damage (mine had rusted out), so maybe it doesn't matter if they aren't made to factory precision.

Jim Wilkins

Reply to
Jim Wilkins

That's what I would expect, and what I'm wondering about. As Robin knows well, making those panels to production accuracy is one hell of a difficult job, even with today's FEA tools and so on. Doing it in the aftermarket, which has to be a small market to begin with, is almost beyond my belief.

I hope I get a chance to look into it further.

-- Ed Huntress

Reply to
Ed Huntress

You wouldn't be able to assemble the panels if the draw die had the same geometry as the finished panel. In hard dies it's *impossible* to ignore springback. It may be less of an issue with hydroforming dies, but I don't think it's non-existant.

I've seen surfaces of dies recut by 10-25mm because the designers misapproximated springback (it takes *days* just to weld up 10mm of a die surface - let alone all the 3d machining, and then the weeks of tryout inside the presses afterwards).

Regards,

Robin

Reply to
Robin S.

(it takes *days* just to weld up 10mm of a

It takes seconds to reshape the flange with a dolly and rubber hammer. I had to pull the joints together with clamps and sheet metal screws before welding. The radiator and other mounts have oversized holes and the brackets were easy to bend with duckbill pliers.

I've done a lot more body work than this one piece, usually small-area rust repair, and I make a patch that matches the curves, MIG it in with a butt joint and hammer the area to shape. I haven't had much luck with Bondo in rust-prone areas but except for fender flares they usually are down low or within the wheel well and the curves don't have to be perfect.

The junction of the wheel well and the strut tower was quite a project to duplicate and it had to be waterproof.

Jim Wilkins

Reply to
Jim Wilkins

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