Re: Fallout 3: Mini-Nuke WIP
Here are the pictures as threatened.
Inside of the bottom mold. On this one the rubber is a little thicker than the top. After talking with the guy at the SmoothOn distributor, I think that is why the bottom of the cast has fewer low spots than the top.
Inside the top mold. It looks good anyway.
Unfortunately, I did not create the part line in the right location. So vacuum and a light mechanical lock meant I did some damage in trying to get the master out. I totally spaced out and tapped on the piece of balsa sticking out the top of the mold with a mallet. I might have saved it if I had not lost one of my compressor attachments when I moved.
First pull. That seam is horrible! If you follow the curve along the top you might see the mold was pushed in slightly just above the seam. I have a theory about that at the bottom of the post.
Here you can faintly see some of the low spots on the top.
More low spots.
Here I tried to get a shot of the one low spot on the lower half. It is in the shadow.
So the problems are a bad seam and some low spots on the top half of the mold. I think the problem with the seam might be because I clamped the shell too tight which compressed the rubber distorting it and pushed it slightly into the mold cavity.
For the low spots I am going to see if I can't use something to keep the rubber attached to the jacket. While talking about the seam the rep said that you can actually superglue silicone rubber together temporarily. So tomorrow (maybe) I am going to take some scrap silicone and cover it with PlastiPaste like I did for the jacket. After it cures I'll try supergluing it to the jacket, let it set, and see if I can remove it. If I can, then I will try it with the mold and pull another cast to see if it comes out any better.
Basically, I made the rubber too thin. While talking with the rep he asked how thick the rubber part of the mold was and asked if it was "this" thick while holding his fingers about half an inch apart. Nope, not even close. I got it a little under a quarter of an inch thick on the thickest part I could measure. Probably half that over most of the mold. I watched the YouTube video from SmoothOn about using Rebound 25 again and at the end of applying the rubber they say it should be about 3/8 inch thick. Oops! Live and learn I guess. Just hope this is the last expensive lesson.