Why does no one make aluminum replacement body panels.

[Backyard]

I have not seen Stamping company make aluminum body stampings why ?? What is everyone's thoughts. Personally if I had the choice I would go aluminum if I had the option and it wasn't overly expensive.


Thoughts?

 

[Keith Seymore]

Because they would be expensive and difficult to make.

K

 

[Ricko1966]

Several reasons,aluminum panels are more difficult to weld and repair and not as strong by gauge. Aluminum is much more expensive,when is the last time you saw somebody collecting tin cans to take in for recycling? There are the galvanic differences between steel and Aluminum that would need delt with to prevent corrosion. And after all these obstacles someone would have to spend the money to tool up and make a product that has a very limited demand.

 

[Blue Ox]

If we're going that route it would be better to make stainless panels. But you'd still run into the same problems. Cost and metallurgy.

 

[Turbo4whl]

If we're going that route it would be better to make stainless panels. But you'd still run into the same problems. Cost and metallurgy.

Back in 1936 Ford made a promo out of stainless steel. Each piece stamped on the standard dies needed to be reworked as the metal sprung back more than the regular steel did.

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[Blue Ox]

Back in 1936 Ford made a promo out of stainless steel. Each piece stamped on the standard dies needed to be reworked as the metal sprung back more than the regular steel did.

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I'm not an expert in stamping sheet metal, but I know stainless has weird properties compared to carbon steel.

If I won the Powerball I might commission a set of dies for a stainless Squarebody. I can't imagine what it would take to make the entire truck that way, but I can appreciate the idea of just polishing it with Scotch Brite.

 

[Keith Seymore]

Coming back to this: a person CAN run aluminum sheet through the existing steel dies, but as noted above the springback is different and so the fit will be different.

My dad worked at Chevrolet Flint Manufacturing - Pressed Metal division (aka "Chevy in the Hole") and had to run some aluminum parts. He took trash bags and lubed them up with STP and placed them in the top and bottom of the die in order to run the aluminum sheet through them. This fills the extra clearance(s) in the die and prevents ripping and tearing of the metal.

If you don't have existing tools then you have the relatively huge time and expense of making a new set of steel or kirksite dies (both a top and a bottom), as opposed to a fiberglass mold where you only need one side, created by something inexpensive (like an existing part).

The springback issue is major. GM runs what is called a "match metal" program, in which they run tons and tons of junk trying to tune the metal so that it all fits, incrementally moving away from the nominal design values*. Smaller firms do not have this luxury which is why their sheetmetal parts usually don't fit very well.

Bottom line - why do all this when you can make fiberglass parts for essentially no effort and with no development, cheaply and end up with a lightweight part?

K

*This wreaks havoc if you ever have to move the tools, say from the US to Mexico. When the tools are set up at the new location they are reset to nominal, so then nothing fits right and the tuning process has to start over.

 

[Keith Seymore]

Not to say it can't be done, if time and money are no object.

This little car is one of six 1963 Pontiac Lemans coupes (there were also six wagons), created specifically for drag racing with a 421 cubic inch engine, special 4 speed transaxle, and aluminum front end sheet metal. It created quite a buzz on ebay a few years back when it sold for $226,521.63 as you see it here. Only one other coupe and one wagon are confirmed to still exist.

When the car was located (in a storage unit! in Harrison Twp Michigan) it had a steel front end on it. Any Pontiac enthusiast worth his salt knows that the original aluminum front end was removed a long time ago and is owned by a guy in Florida. When he was approached about reuniting the original front end with the car his asking price indicated that he didn't really want to do it. As a result the restorers decided to fabricate a new aluminum front end from scratch to complete the car. The parts were hammered by hand over small forms with soft mallets and sand bags, and then joined together to create the larger assemblies.

K

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[Keith Seymore]

In addition to my Dad's 26 years as a die maker in Flint I have a little sheetmetal experience of my own.

At one time I had design/release responsibility for the GMT900 pickup front of dash and underbody, pickup box, and G van underbody structure.

I also worked on a low volume production/show vehicle and had responsibility for everything you can see from the outside except the tire/wheel and wheel cover (that is, front and rear fascia, body panels, beauty glass and exterior trim).

K

 

[Keith Seymore]

I am attaching this picture for no particular reason at all.

K

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[Keith Seymore]

The springback issue is major. GM runs what is called a "match metal" program, in which they run tons and tons of junk trying to tune the metal so that it all fits, incrementally moving away from the nominal design values*. Smaller firms do not have this luxury which is why their sheetmetal parts usually don't fit very well.

Total sidebar: they also used to make scale models of stamped parts to test the "draw" of the metal, since the characteristics can be scaled down (known as "similitude". You can do that more famously with wind tunnel testing as well).

One time they made a bunch of 1/4 scale Chevrolet oil pans. After they had fulfilled their purpose they were supposed to be thrown away, but somebody ended up keeping them.

For the longest time after that any time somebody retired, or had some other significant event, they received one of these quarter scale oil pans, chromed, mounted to a nice plaque.

K

 

[Keith Seymore]

Now I'm done.

You can see my post #2 was "pregnant" with meaning!

K

 

[idahovette]

@Keith Seymore NAH, you're not done....there's a WEALTH of information left!!!!!!........thanks Keith, keep it coming!!

 

[TotalyHucked]

I'll chime in a bit too since I work for an aftermarket restoration sheet metal company (AMD). As stated earlier, nobody makes aluminum parts for these trucks due to high costs and stamping challenges. We did a couple runs of aluminum parts for '69 Camaros about 10 years ago now, the whole front clip and the rear decklid. Those parts were easily 3 times, maybe 4 times more expensive than the regular parts (my memory is a little fuzzy and I was only working in the warehouse at the time, not in sales or R&D) and fitment was not as good because they were made on our standard steel dies.

We ultimately discontinued them because of slow sales. The expense was the number one reason they were slow to sell but they did not fit very well. The factory had to massage each piece after it was stamped but without fitting each piece to a car, you can only do so much. We also did a couple small runs of S10 cowl hoods, thinking drag racers would scoop them up. But it was the same issue, too expensive to be feasible. If shedding weight is your goal, fiberglass is definitely the way to go.

 

[Keith Seymore]

I have not seen Stamping company make aluminum body stampings why ?? What is everyone's thoughts. Personally if I had the choice I would go aluminum if I had the option and it wasn't overly expensive.


Thoughts?

I hope we've answered your question.