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Old 01-17-2019, 09:17 PM
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Jack 1957 Jack 1957 is offline
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Join Date: Sep 2014
Location: Strongsville,OH
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The last thing I need to get done on the front end is the parking lamp housings. I think the most efficient way to make these would be to cast them in aluminum. My go to guy with a home foundry has left us for greener pastures so I'll have to find someone to do the pour for me, but I can make the moulds
Since I'll be casting the tail light housings also, I'll do them all at one time.
I thought about making them from 24ga stainless but they'll be pretty intricate and a lot of welding in tight areas on thin sheet metal. Plus, bolting them together would probably leave indentations on the finished outer surfaces.
There are a few different ways to do this but I'll be using a method called lost wax investment casting, or plaster casting. It involves making a wax plug, then pouring a mixture of plaster and silica sand around it. When the plaster mix is cured, you flip it upside down and heat it to melt the wax and it runs out of the mold. Then heat the mold to at least 800 degrees for about 6 to 8 hours to get all the moisture out of the mold, then pour the aluminum.
The downside to this method is that it's very dangerous and you could get killed or seriously mamed. Also, you don't know if you have a good mold until the very end when you bust the mold open and inspect the part. The plug is lost and the mold is destroyed so if the part is bad you have to start over from the very beginning. The upside is that if all goes well you have some very clean, well made and durable parts that will polish up easily.
The first thing I did was take apart a headlight and a tail light to sort out what I need and where everything will go and to determine the shapes of the housings.

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This is the part that can get you killed or severly mamed. Grab your wife's electric skillet and some tin foil and get out to the garage quick. Don't forget to hang the "Do Not Disturb" sign on the door. (You didn't think I was talking about the pour, did you?). Fill the skillet about half full with water and hang some foil around the sides to reach down below the water line, and turn the heat on to about 200 degrees. This will bring the water temp up high enough to melt the wax but not hot enough to boil the water. Bust up the wax into smaller chunks and put it in the skillet to melt.
You'll have to experiment with how much wax to use. I wanted a sheet of wax about 3/16" thick. I ended up with closer to 1/4" thick. A little overkill, but I'll use it. This skillet is 12 x 16" I put about 1 1/2 pounds of wax in and came up with almost 1/4" thickness.

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As the wax melts then starts to cool, it will start to shrink. The foil will help keep the wax from splitting because it will move out with the wax as it shrinks instead of the wax sticking to the side of the skillet. You'll probably get some air bubbles so use a micro torch to pop them.

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When the wax is mostly cooled lift it out, set it on a flat surface and set some weight on top to keep it from curling up til it cools completely.

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I had 4 1/2 pounds of wax and got 3 sheets from it. I'll probably need more but I'll see how far this gets me.

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Next, I got some of this green foam. I think it's called wet foam or something like that. It's that stuff you see in flower arrangements. They poke the stems into it. It's very soft, light and very easy to work with. It's good for what I'm doing here with wax but not for anything heavy. It's not strong at all. You can cut through the whole block cleanly with a steak knife and finish on a belt sander in less than 5 minutes.

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Last edited by Jack 1957; 01-17-2019 at 09:28 PM.
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