Technical Silicone mould and resin use in parts fabrication.

I’m presently restoring 7 x 53 Eldorados all at once.
Pot metal exterior parts have presented many problems in even sourcing repairable parts.
I’m looking at replicating these parts in resin or fibreglass and then chrome by use of graphite coating to hold electric charge.
Anyone got any tips or previous success using silicone mould and subsequent casting techniques?
I have access to a nos pair of these fog housing. Finding a decent pair these days is nearly impossible and I need at least 5 good pairs.
These ones are on eBay and will require substantial repair before they are able to be chromed.

 

For something that size, is resin shape stable?

 

I think it can be done. But there are many types of resin so you have to choose the right one. One that does not warp on a hot sunny day and that is not too brittle.
Or maybe it could be made with a 3D printer?

 

There used to be an old fella here in Adelaide who would re-cast this kind of stuff in pewter, then have it chrome plated. The pewter is soft, but the chrome plating is hard, and would be fine for these. I had some Caddy bits and badges re-cast by him , using a good original a for a pattern. Unfortunately he passed away a few years ago, and I don't know who else does this. Silicon moulding is very popular, and I think that the moulds can be used with pewter (because of it's low melting point). That's the only way we could figure out how the old boy used to cast them.

 

I’ve done a lot of casting with silicone molds and resin.

Contact Eager Polymers. http://www.eagerpolymers.com/ Talk to their tech guys. Explain the project, they’ll help you choose products to make it work.

Bubbles are your enemy.

Bubbles in the mold become bumps in your part that will have to be dealt with. In my case that means pulling a vacuum on the silicone before pouring it, and a slow build up to minimize bubbles in the mold surface.

On the pour of the resin, you also have to deal with bubbles. My molds go in a pressure tank at about 75 PSI after pouring to crush any bubbles in the resin.

I’m using a heat cure resin, so there’s also time in an oven to finish the parts.

 

The guy making the “waterfall” had some success with this. Check out his thread for details.

https://www.jalopyjournal.com/forum/threads/1935-ford-waterfall.1178935/