Casting vs injection molding - which method works better?

I’ve actually tried making cornstarch-based molds at home - super cheap, but honestly, they don’t last long. Maybe two or three casts before they start falling apart, especially with anything warm. For small runs, I still think basic silicone is the best bang for your buck. Biodegradable stuff sounds great in theory, but unless prices drop or durability improves, it’s tough to justify if you’re watching every penny.

Casting Vs Injection Molding - Which Method Works Better?

I’ve been wondering about this too. I tried a couple of those “eco” mold recipes and yeah, they just don’t hold up. Silicone’s been my go-to for little projects, but I’m curious - has anyone here actually tried injection molding at home? I keep seeing DIY setups online, but it looks way more complicated (and expensive) than just pouring into a mold. Is it really worth the extra hassle if you’re only making a handful of pieces, or is it more for bigger batches?

I keep seeing DIY setups online, but it looks way more complicated (and expensive) than just pouring into a mold.

You’re right, DIY injection molding setups are a whole different animal. For small runs or unique pieces, casting - especially with silicone - tends to be more practical. Injection molding shines when you need high repeatability and larger quantities, but the upfront effort and cost rarely make sense for just a handful of parts. I’ve seen some home setups, but they’re usually pretty limited compared to what you can do with a simple casting mold.

“the upfront effort and cost rarely make sense for just a handful of parts.”

That’s been my experience too. I tried building a small injection setup once for some recycled plastic tiles - honestly, it was more hassle than it was worth for my little batch. Ended up switching to silicone molds and casting instead. Way less waste, and I could tweak the design without redoing everything. For one-offs or prototypes, casting just feels more flexible.

Couldn’t agree more - casting just makes sense for small runs or when you’re still figuring out the design. I’ve seen people sink way too much time and money into DIY injection setups, only to realize they’re locked into a mold that’s a pain to change. With casting, you can actually experiment and iterate. Sure, it’s not perfect for everything, but for prototypes or custom pieces, it’s just more practical.