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Q: Stamping using plastic parts?

04-09-2016, 02:58 AM

so I'm at a point in a project where I want to try stamping of thin metal sheets to get a part to have the shape of a plastic part but be made of the actual material.
My idea is to cast a negative mould of the part in question using silicone or resin or whatever (need input there) and use that to stamp the metal (cut open soda can). The original thought was to cast the original part in plaster and use that plaster as the die and then use some rubber tip small hammer or tool in a punch like fashion shaping the metal into the mould form. However, given my experiences with plaster after maybe 5 hits (if that many) the mould would crumble and turn into dust.
So I've been wondering... is there a malleable silicone / resin out there? Something that can be cast as a mould but is stable enough to lightly hammer a thin sheet of metal into shape on?

As for the part - for argument's sake think of the door sill on a GT40 (scale is 1/12). Of course you could just solder some half round rods of whatever to a flat sheet and recreate it, with the rods slightly smaller in diameter than the actual shape of the real part (to account for the thickness of the metal to be shaped over it). That is easy enough for that part, but if you get to more complex parts you could just as well build the entire structure from scratch - which I'm disinclined to do as aluminium is not something I know or have the tools to solder (or weld or whatever).
Also with the stamping solution it would be easy to create more than one copy as opposed to scratch build each one separately.

Ideas? Opinions - or have I gone off the deep end (again)?

04-09-2016, 07:03 PM
Try this link and on this page search for the word "stamping".

You might find this technique helpful. Hope it helps.

04-09-2016, 07:06 PM
Funny enough, this wip is back on the Motorsports section. See "1/8 talbot lago t26c" in this section.

04-10-2016, 01:48 PM
I know Dan's thread. I love every single bit of it. However, the stamping he did was for easier shapes for the most part. I think he used stamping twice - once for the drumbrakes and the second time for a firewall. He created the outline for that firewall on a piece of wood, cut the center bit out and drove it home by bolting a piece of sheet metal to the wood piece with the cut out and then use a vice to press the cut out bit into the sheet metal so it would shape the metal.

That aside, I have found a rubber, that might be useable for my purpose. I guess I will have to try it (Ebalta GM 984-2 in case anyone is interested). It is said to be excellent to pour and cures to a good strong but slightly flexible hardness (think rubber hammer tip).
Other ideas involve using a separation agent followed by a (few) thin layer(s) of gelcoat followed by something that is very strong. Something harder than plaster that won't crack and break when tapped with a hammer.... The gel coat is just to get a smooth surface in case the harder "background" material has a rough structure....

04-10-2016, 07:33 PM
Sorry I couldn't be more help. Please keep us informed of your progress.

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