I have been reading the blog for a long time, but this is my first post in the discussion board. Your help will be greatly appreciated.
I am working on an basketball shoe project. I want to hand make my own working prototype shoe.
I have taken a mold of my feet to work off as a last. I am now in the process of hand sculpting what I want the midsole and outsole to be.
I want to use these to make a mold that i can then use to make usable shoe parts.
How can I do this?
What materials would you recommend to use for the mold.
And then how can I get liquid vulcanized rubber for the outsole and / or polyurethane for the midsole to make the parts out of.
I think make magazine had a pretty sweet breakdown of a style of the process using hardened shells (letting you create more than if you just used silicone).
As far as vulcanized rubber, unless you want to go for Room Temperature Vulcanization (which I don’t think would work for your purposes) you may be out of luck.
the only thing that comes to mind is plastisol… i haven’t done it myself so not sure if it would be perfect for your application but it’s at least worth reading about. I think you need to heat it to ~400F.
But it’s PVC, so don’t use anything you will ever use again for food.
The “hardness” of engineered materials is a measurement of durometer. There are two scales; Shore A and D. The Shore “A” scale is the measurement system used for “soft” materials (a skate board wheel); Shore D is for “hard” materials (a hard hat, or cellphone housing). There is actually a third Shore scale; OO. Chewing gum would be Shore OO.
Here are two hits from a “Shore A urethane casting materials” google search:
Urethane materials can be cast at room temperatures into silicone RTV molds. It can also be used as a mold making material itself. It’s a really aggressive material (meaning it likes to lock onto mold materials) and a suitable mold release should be used even with silicone molds; especially if your part is intricate (like the tread pattern on a shoe sole). You would have to have an original “pattern” to cast your RTV tooling onto.
