Yeah, totally get you on the bubbles issue—had a similar headache myself once trying out resin casting for a small-scale architectural model. Spent hours sanding and patching those tiny imperfections... not fun. Injection molding does seem more predictable, but honestly, I think it's worth considering the scale and complexity of your project too. If you're doing something intricate with lots of fine detail, injection molding can save you a ton of hassle down the line. But for simpler, one-off prototypes or quick concept models, casting's flexibility and lower upfront cost are pretty appealing. Also, have you tried vacuum degassing your casting materials? It made a huge difference for me—really cut down on bubbles and imperfections. Curious if others have had luck with different additives or techniques to make casting more reliable...
"Also, have you tried vacuum degassing your casting materials? It made a huge difference for me—really cut down on bubbles and imperfections."
Vacuum degassing is definitely a lifesaver when you're dealing with resin casting. Another thing that helped me a lot was warming the resin slightly before mixing—it reduces viscosity and lets bubbles escape more easily. Just be careful not to overheat it, or you'll end up with a shorter working time.
Injection molding is great for detail and consistency, but the upfront costs and lead times for molds can be a real barrier, especially if you're still experimenting with your design. For smaller-scale architectural models, I've had good results using silicone molds with pressure casting. Basically, you pour your resin into the mold, then place it in a pressure pot at around 40-50 psi while it cures. It compresses any remaining bubbles so they're practically invisible.
It's not perfect, and there's still some cleanup involved, but it's way less tedious than sanding out tiny imperfections afterward...
Pressure casting definitely helps—I've seen some impressive results from it. But have you noticed any issues with mold durability under pressure? I've had a couple silicone molds deform slightly after repeated use at higher psi, though maybe I wasn't using the right silicone type...
Injection molding is fantastic for larger batches or finalized designs, but yeah, those upfront costs can be brutal if you're still tweaking things. Resin casting seems way more forgiving when you're still in the prototyping phase. Also, warming resin is a solid tip—I learned that one the hard way after spending hours sanding out tiny bubbles from a detailed facade model.
Have you ever tried vibrating tables or even just tapping the mold gently to help bubbles rise? It's a bit low-tech compared to vacuum or pressure setups, but sometimes simple tricks can save you a lot of hassle.
"Have you ever tried vibrating tables or even just tapping the mold gently to help bubbles rise?"
Yeah, tapping molds has saved me more times than I can count, especially when I'm working on detailed trim pieces. I've never had silicone molds deform under pressure myself, but maybe that's because I stick to lower psi settings. Curious though—has anyone experimented with reinforcing silicone molds somehow to handle higher pressures better? Seems like there might be a workaround there...
I've had good luck tapping molds too, especially for smaller detailed parts. Never tried reinforcing silicone molds directly, but I have seen people build a rigid outer shell or frame around them—usually wood or acrylic—to help maintain shape under higher pressures. Seems like it could be a simple fix without having to mess with the silicone itself. Might be worth a shot if you're pushing the psi limits...
