Metal Casting and Plating Auto Body Emblems

[porschedude996TT]

My latest project involves making new fender emblems for my muscle car and casting them in brass and then plating them in my shop.

I have a 1969 Camaro that is a clone so don't get up in arms over modifying a classic car. It was not an original Z/28 but has the emblems and such. It does not have a 302 CI engine as fitted with a factory Z/28. It has a .060" over bored 454 CI engine which equates to 468 CI. I had an idea to change the body emblems to something that never existed from the factory. It would reflect something very different. The new emblems will state the engine displacement (Z/468) rather than the original option number (Z/28).

I told a friend at work about it and he wanted in and is making the first generation positives. He has made molds for poly resin casting in the past and has even casted some low temperature metals and so have I. He had and old RTV mold that we tested to cast brass. It held up for the one part, but the mold was toast after the first pour. We are making four total parts for the car which equates to two of one casting (Fender Emblem) and two of another size which has different mounting pegs for the front of the car and the back of the car. So we are making a part that will be casted and then mildly machined to fit either the front or the back.

 

[nine4gmc]

In for info.

 

[n8n]

Nice.

Wish I'd known someone that could do stuff like this a few years back, I needed some C-pillar emblems for a Studebaker Lark, that was a bit of a search, and I ended up having to source some beat originals, then have three different platings done on them (copper, nickel, and gold)

 

[kazlx]

For a couple emblems, maybe it would just be easier to fully machine them...couple hours in a CNC box once you have a file.

 

[gte718p]

Not a lot that is going to hold up to multiple metal pours, even at the relatively low melting temp of brass. The easiest way to do it is to make a wax positive out of the RTV mold, pack it in sand, make a couple of risers, pour into the sand mold. The wax will melt and vaporize. Repeat. The sand can be used repeatedly.

 

[A_Pmech]

Why must they be brass? Most original emblems are die cast and plated zinc. Some of the zinc casting alloys melt at a low enough temperature to be cast in silicone molds without damage.

 

[porschedude996TT]

In for info.

No problem.

For a couple emblems, maybe it would just be easier to fully machine them...couple hours in a CNC box once you have a file.

I am a Design Engineer and have access to 3D modeling software and we even have a nice 3D Printer, but I'm not sure the US Gov wants us to make Camaro Emblems on their equipment. Plus we wanted to do this old school as they say... I wish we have a digitalizer to scan the original...nah, not worth getting fired at the age of 58 years old and retirement on the horizon.

Not a lot that is going to hold up to multiple metal pours, even at the relatively low melting temp of brass. The easiest way to do it is to make a wax positive out of the RTV mold, pack it in sand, make a couple of risers, pour into the sand mold. The wax will melt and vaporize. Repeat. The sand can be used repeatedly.

Understand that, but sand casting does not give you as fine of detail as plaster. We thought about lost wax investment casting and we could go down that road, but for now we plan to use some high temp plaster mix and make four molds from the two positives.

Why must they be brass? Most original emblems are die cast and plated zinc. Some of the zinc casting alloys melt at a low enough temperature to be cast in silicone molds without damage.

I think you were trying to say they were die cast zinc and chrome plated, yes? No real reason for brass unless I leave them bright brass. I guess I could use zinc or aluminum which would greatly lower the melting point we would need to obtain. I can plate the aluminum using a pretreatment called zincate or is I used zinc I could directly plate with copper etc.

Thanks guys, I'll post some pictures of the progress if your interested.

Keith

 

[kazlx]

You are probably infringing on designs by casting too...never said you had to machine them at work...

 

[zkling]

BTDT more than a few times. I use to or actually still do have a small foundry setup for small pieces like that. Done a handfull of emblems for people. Mostly for older outboards, tractors and classic cars, and on occasion belt buckles (no joke). Nothing to exotic. Bronze and aluminum.

I requested that a sample copy be brought, I would make a negative mold from that, then pour casting wax to make a positive, which was then vented, gated and invested (plaster like mixture). Dried, burnt out the wax, leaving with a negative mold that could withstand the heat and provide a fine detail. I'd suggest you talk or look into local places that do bronze art sculpture. Even the local college. They will be able to tell you who in the area can provide supplies.

Edit,
A little word to the wise. I'd keep hush around the true collectors. Some can get pretty snotty about not 100% repos being made.

 

[Southernbuild]

BTDT more than a few times. I use to or actually still do have a small foundry setup for small pieces like that. Done a handfull of emblems for people. Mostly for older outboards, tractors and classic cars, and on occasion belt buckles (no joke). Nothing to exotic. Bronze and aluminum.

I requested that a sample copy be brought, I would make a negative mold from that, then pour casting wax to make a positive, which was then vented, gated and invested (plaster like mixture). Dried, burnt out the wax, leaving with a negative mold that could withstand the heat and provide a fine detail. I'd suggest you talk or look into local places that do bronze art sculpture. Even the local college. They will be able to tell you who in the area can provide supplies.

Edit,
A little word to the wise. I'd keep hush around the true collectors. Some can get pretty snotty about not 100% repos being made.

Any pictures of your setup? It sounds interesting

 

[zkling]

Any pictures of your setup? It sounds interesting

What sounds interesting about it? Ghetto maybe more like it. I'll do some digging. I posted pics of the furnace a while back in another thread where we talked about casting. :

 

[porschedude996TT]

You are probably infringing on designs by casting too...never said you had to machine them at work...

I think I'm ok as l am not making the exact copy of the emblem. Using the OEM emblem, then only using a part of it breaks any copyright. That and I'm making them for my car and not selling and profiting from the venture. Yes???

 

[Southernbuild]

What sounds interesting about it? Ghetto maybe more like it. I'll do some digging. I posted pics of the furnace a while back in another thread where we talked about casting. :

I've been interested in metal casting for a while, and am always looking for info / pictures. I really need to try it someday, so the scrap metal I'm saving to use as project materiel won't be underfoot.

Or, I'll have a reason to collect an even bigger pile!

 

[kazlx]

I think I'm ok as l am not making the exact copy of the emblem. Using the OEM emblem, then only using a part of it breaks any copyright. That and I'm making them for my car and not selling and profiting from the venture. Yes???

I don't really care either way. I would make them too. You just responded to my point about just machining them with info about not wanting to do it at work or whatever. I was just stating that it sounds like you already know the software and could have just loaded a couple blanks of aluminum in a CNC mill already and had them done. Casting works, but not exactly fast unless you are already set up for it.

I think there is absolutely 'zero' chance of anyone (I mean copyright wise) caring what you make for your own car that you aren't selling.

 

[aka Larry]

I think I'm ok as l am not making the exact copy of the emblem. Using the OEM emblem, then only using a part of it breaks any copyright. That and I'm making them for my car and not selling and profiting from the venture. Yes???

If they are for your own use (not selling them) you'll be fine. I really hope GM has something better to do anyway.

I'm sure all of us would want to see the pics of what you end up with so please keep us updated.

 

[48RON54]

I think I'm ok as l am not making the exact copy of the emblem. Using the OEM emblem, then only using a part of it breaks any copyright. That and I'm making them for my car and not selling and profiting from the venture. Yes???

People make small quantities of items for cars from the 30s/40s/50s in their garages all the time. I wouldn't worry about it too much unless you are trying to move thousands of them on a public auction site with a huge obvious GM in the middle of them or somthing like that.

 

[porschedude996TT]

Ghetto maybe more like it.

Why does this sound "Ghetto"? Please explain.

 

[mjb]

Why does this sound "Ghetto"? Please explain.

Pretty sure he was talking about his casting set up.