The Ford Barn

nkaminar · 06-24-2025, 05:20 PM

Traditional rubber needs to be cured at high temperature but there are rubber like compounds that cure at room temperature. Silicone gasket sealant is one. Polyurethane is another. There are many other polymers.

I have cast polyurethane for a machine that I was designing. First I made the plug that is the male part used to make the mold. Then I cast silicone to make a mold. Then I cast the polyurethane into the mold. I made a few parts. The material that I used does not shrink so the plug can be the final size and shape.

The mixed components used for the mold and for the part have to placed in a vacuum chamber to de-air them.

It takes a while for the polyurethane to set but that maybe could be sped up with some moderate heat.

06-24-2025, 05:20 PM	#5
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 5,854	Re: Rubber Casting repro parts. Traditional rubber needs to be cured at high temperature but there are rubber like compounds that cure at room temperature. Silicone gasket sealant is one. Polyurethane is another. There are many other polymers. I have cast polyurethane for a machine that I was designing. First I made the plug that is the male part used to make the mold. Then I cast silicone to make a mold. Then I cast the polyurethane into the mold. I made a few parts. The material that I used does not shrink so the plug can be the final size and shape. The mixed components used for the mold and for the part have to placed in a vacuum chamber to de-air them. It takes a while for the polyurethane to set but that maybe could be sped up with some moderate heat. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past. Last edited by nkaminar; 06-24-2025 at 05:38 PM.