View Full Version : How Do I ID This Metal & How Do I Cast It?

03-08-2006, 01:53 AM
One of my jobs at the moment is working for the guy who is restoring the Tucker that used to belong to George Lucas and on the engine deck lid (what would be the trunk on most cars) is an emblem of the Tucker family crest. The boss and I figured that it'd be a pretty goog idea if we made some reproductions of the thing, but we're not really certain what it's made of. It LOOKS like copper, but it hasn't turned green, and it seems fairly hard (but I haven't done any kind of tests to see how hard it is, since the car's worth $500K). I'm thinking it MIGHT be red brass, but I don't know. Anybody have any guesses? And how do I cast whatever metal it is? I've done tin, bronze, aluminum, and various steel alloys, so there's no danger of me setting myself on fire, but I've not had to figure shrink for anything, and given that it's most likely an alloy I've not poured before, any tips on how to do it would be appreciated.

03-08-2006, 01:59 AM
Wouldn't hazard to guess on a Tucker - long befor my time!

But those are usually a zinc alloy aren't they. then plated? Might well have used something better back then, or it would have corroded away by now.

03-08-2006, 03:02 AM
You might weigh it under water, calculate its specific gravity. Or displace water with it, as accurately as possible, weigh it determine the specific gravity, consult the charts.

Particularly if you know it is a copper bearing alloy, you can determine what it is closely.

Potmetal, likewise, though I think it would have been a better grade of metal back then, and being a Tucker. He did not skimp.

Brass will corrode, so more likely gold plated, though which colorant metal was used,
I could not say. Different alloying metals caused different surface colors without reducing the carat/percentage of gold. Could be 4 carat, still look like "real" gold, same alloying agent, still the same hue.



03-08-2006, 03:24 AM
In addition to what gmatov suggests, you could also try asking these guys (http://www.tuckerclub.org/bbs/index.php), they might know what specific alloy is used, probably a long shot though.


This Old Shed (http://thisoldshed.tripod.com)

03-08-2006, 08:42 AM
These guys http://www.paulrussell.com/ would probably know -- or be able to find out -- but it would likely cost you something for their time.

But if the car is worth $500K, presumably somebody has enough money to pay for some consulation fees.

03-08-2006, 08:56 AM
Here is another,


[This message has been edited by topct (edited 03-08-2006).]

03-08-2006, 11:29 AM
No idea what the base metal is but I suspect it is plated with rose gold.

03-08-2006, 09:43 PM
By then, auto makers were already using die-cast. It's an Aluminum/Zinc alloy. This was then plated. I've melted down old carburetors to duplicate door handles.

It may have been cast bronze, polished then coated with clear lacquer or plastic. Hard to say without seeing it.

Got any close-up pics?

03-09-2006, 01:39 AM
<font face="Verdana, Arial" size="2">Originally posted by SGW:
But if the car is worth $500K, presumably somebody has enough money to pay for some consulation fees.</font>True, but the people with the most money are the ones least likely to spend it. Still, I do have a friend with access to a spectrometer, but I don't know if it can hold the part, or if it's set up to analyze anything other than steels. I should be able to post photos of the emblem on Sunday.

03-09-2006, 01:20 PM
Found a copy of the original blue print. Apparently, it was plated with 14K gold, but what the base metal is, it doesn't say. Will upload the print pic along with the photos this weekend.

03-09-2006, 02:10 PM
It's rose gold then. Rose gold is about the same color as copper but never tarnishes.