Using the epoxy was a BIG el FLOPPO. It did not produce the detail I had expected. The epoxy that I used is a different flavor than what I have worked with before, so that might have something to do with it. It doesn't matter though because I quickly found out that two part epoxy is not a good fit with two piece molds. You basically have to squish the mold together and that can lead to distortions with the cast. The best solution would be a liquid resin.
This presented a dilemma. I can't use quick setting resin because the resin generates heat, and heat softens blue stuff. It would basically destroy the mold detail. The only other option to consider is a slow setting resin, and I just so happen to have some called Puduo. As a hail marry pass, I tried it. And what do you know-- it worked very well.
I am amazed at the amount of detail that both the Blue Stuff and the Puduo had produced.
At this point I could stop here and move onto making all 4. The downside is that the mold process won't allow me a more precise finished piece. This cast needs to be trimmed not only along its circumference, but also within it's spokes. It could be a lot of work. This got me to thinking. I have gone this far-- why not make a better mold using silicone. Yeah, I'll have to drop about $35 to buy it--but I should end up with a much better end product. If done correctly, there ought to be little flash, and the internal structures should come open like the master is. Or at the least, maybe a thin film of flash that can be easily trimmed. The above will not be easily trimmed. I'd have to grind them open.
I could also purchase a fast setting resin but that is another $35 to $40 bucks. This is why I like to avoid all this fuss with molds and such. In the end I could spend $70 to $80 just to make 4 wheels. That is ridiculous. And to make things worse-- these products have a shelf life, and a short one at that. If I could use them for a future project, that would be a different story. But that is not the case. Once opened the resin goes bad after maybe 3 months, not sure about the silicone, but I hear it is not that long either.
So-- for the sake of a better product and to take a shot at learning a new process--I will buy the silicone. For the resin, I will stick with the Puduo. It seems to work well. The main downside with their product is that I have to wait a good 2 to 3 days before demolding it. That's ok, I can wait.
A few more points:
1. I plan to attach the hub and rivets so that they become part of the mold/cast. This will reduce some work and gain some consistency. I need to make sure the master is done right then.
2. Remember what I said about the bubbles and Blue Stuff? I think I figured out the problem. As in the video it is recommended that the product be boiled until soft. Here is the problem. Doing that introduces water into the mixture and that creates pockets in the mold. I decided to use a heat gun to soften the material and guess what? I had seen no issues with divots. If anyone tries this -- just be careful. The stuff gets gooey and if too hot-- you can burn yourself. Blue stuff is cool stuff, and it has its place for simpler molds.
And that is enough bloviating on my part.