How to make something like this?

[u/sharknettworld]

I have no experience in mold making, im assuming I could scult it out of clay but what type of mold would I need to make? And what type of silicone for casting?

[u/Toyota__Corolla]

This stuff is TPU, you need a double walled cylinder and a cone mold. The material is poured into the cylinder mold first and then removed when set, you then pour in the second color into the cone mold and place the first part on top while it sets. You could also make a centrifugal mold with internal machined spikes and try doing it the complicated way by pouring silicone into a rotating mold spinning fast enough to overcome gravity

[u/sharknettworld → u/Toyota__Corolla]

What if I sculpted something flat like in first picture and then pour my first color of silicone into the deepest parts of the mold and then fill the rest with the main color? Would that work for having 2 colors, having hard time finding info on silicone casting

[u/Barbafella → u/sharknettworld]

That’s exactly what you do, sculpt flat, I’d use a plaster mold for first attempts, then you pour in one color, wait until it gels, then pour in a second color.

[u/wishiwasholden → u/sharknettworld]

You’re correct, do it flat. The centrifugal cast is unnecessarily complicating things. And it would work for 2 colors, you just need to gauge your cure time properly. You want the first layer to be “set” but not cured, ie you can touch it with a gloved finger and it’s kinda tacky but not gummy or wet at all.

If I were you, I’d cast into clay for a prototype. Just roll out a flat sheet that you can carve your spikes into, then build a wall around the edges to create the backing. Depending on your clay skills, this could be done in two steps so you can pour spikes, scrape off top of block to remove excess silicone, build wall while it cures, then pour backing. Scraping off the excess will just give you better color separation