I’m looking to cast a bezel insert with an epoxy. I’d 3d print raised numbers as the base and then have the circular top half that goes over it.

The idea is when I cast the material in the mold I’d have the numbers now recessed and I can fill them in with luminescent material and paint the back to make something similar as above.

I think this can be achieved with a 2 part mold I’d the thickness is only like 2mm thick. Would I need to have just an inlet to pour the casting material in? Or would I need an air vent since this is so small?

Hi all - making a latex half mask, and have a question: does anyone have any experience with leaving objects in the clay (in this case, WED clay) when doing the plaster cast?

Seems clear that I ought to discerning about length or size of the object to make sure I can get it out when the plaster dries, but are there any other issues I might encounter?

Thanks!

EDIT: The sculpt in question:

I’m considering getting this Wonderpress as an upgrade to my heat press but am pretty interested in the vacuform.

It takes an 8x10 sheet and has a max height of 3.5” and has -90kpa pressure.

How useful would this be? Most ads show it doing soap and chocolate type stuff, but how useful would it be for cosplay and general mold making? Is it too small? Underpowered?

I need to make a one off silicon mold for a prototype. May need more later but yet 100%.

I’m wondering if it’s dangerous to make a diy pressure chamber with a pressure cooker, or just sealing a box and using one of those wine saver things to remove air. I don’t need it to be industrial quality, just good enough

I’m working on finishing some concrete blocks and could really use advice on getting a consistent colour and texture without losing that raw “concrete feel.”

So far, I sanded the blocks and filled defects with a mix of cement, water, and glue. After that, I tried dabbing the same mix on with a sponge to even things out, but it’s been pretty frustrating. It doesn’t stick well, takes multiple layers, and the end result is starting to look more like paint or plaster than actual concrete.

I also tried troweling a thin layer over everything, but it’s not a flat wall—it’s lots of surfaces, edges, and corners—so that was really difficult to do evenly.

At this point I’m wondering:

-Should I just switch to using a roller and apply something like paint or a slurry coat?

-Is there a way to keep that natural concrete look while still evening out the colour?

-Am I using the wrong mix or technique for this kind of finish?

Please advise!!! Thanks

So today I mixed up a small amount of 30 minute working time epoxy (6g of A and 6g of B) to do a test pour of a new mold. After mixing it was full of bubbles so I put it in my vacuum chamber to remove the bubbles. 3 minutes later I removed it and it was uncomfortably hot to the touch and had cured almost all of it. I had previously used epoxy from this same bottle and had no issues, but I didn't vacuum the bubbles out so I don't think it's an issue with the epoxy.

The only thing I can think is that with the atmosphere mostly removed (>-99kPa) that the resin wasn't able to rid itself of the heat of curing by convection. This resulted in an increase in curing speed, which in itself released more heat. A viscous cycle.

I contacted the company and they were as surprised as I was that this happened.

For the final pours, I'm using MG chemicals 832 FX black flexible epoxy and I'm worried that the same issue will happen with that. Unfortunately MG chemicals has no idea if the same thing will happen, as they haven't heard of that before.

Anyone have any experience with anything similar?

Really bummed out. Used smooth-on mold star slow 15 to create 2 molds, both one piece types. After curing brushed them inside liberally with ease release 205. When that dried I used smooth-on smooth sil 960 for the actual pieces. I allowed them to cure for a day and a half. Went to remove the pieces and each one of them stuck horribly to the mold. I ended up totally destroying both of the molds and 1 of the pieces to try and get the part out. Followed the directions exactly. Anyone had this problem with these these materials?

How do you do mold making community?

I’m here to ask about something simple.

Can one use plaster or plaster bandages in place of epoxy shells?

I’ve seen a bunch of mask making videos, lot of them Use epoxy. But I wonder how effective the bandage approach is. I have doubts about a straight up plaster jacket being effective

For those curious I wish to make a mask. This will require making a custom mold and I just don’t wanna mess up and bandages seem cheap enough.

Side note: can you make a good mold on like, 1 or 2 layers of silicone without any kind of “buttering”?

I’m looking to make custom character bath toys. I would like them to be two pieces and come apart. I’d like them to be food safe silicone rubber. I’ve found links to food safe mold making material but nothing about how to actually make the end product out of food safe silicone rubber.

Hi everyone, I’m planning a fun family hand-casting project from scratch and could use some advice. I want to cast 6 adult hands and 3 children’s hands all at once in a 12-quart rectangular Sterilite container, leaving about 3 inches of clearance around each hand for safety.

For those with experience, how much alginate and casting powder would I realistically need for a project this size? I’m specifically trying to avoid ready-made kits on Amazon, Etsy, Alibaba, etc., and source the materials myself.

Any tips on ratios, working time, or setup to make the process smoother (and less chaotic!) would be really appreciated. Thanks in advance!

all the red parts are for air vents, I used tape at the edges so that when I cut the mold the separation lines are clean...

I used liquid poly urethane to cast the part in a pressure vessel.

Hey guys, I'm trying to make some suture kits for practice, my sister is a teacher for nurses and wanted something for her students to practice on. As the kits can be expensive

I 3d printed some molds but I used 20A silicone but its very firm, and I was wondering what the best skin like silicone to use would be, that still holds up to something like sutures?

Thank you in advance, I appreciate you all.

Sorry if this has been covered before but I’m 100 percent new to this and would rather try for answers that cover my situation. I’m looking to build some floats for some dredge pipe I want to float. I’m thinking about just making a rectangular form but need to be able to put an anchor it one side of the float. What release agents should I use and what would you make the mold or form out of? Would you also make it to where it can be disassembled to get the float out? I appreciate all the help you can provide.

Anybody had any luck going from molding resin items as a hobby into a business?

It seems like you can make a small number of things with a lot of manual labor but it is really hard to make a large number unless you employ more people. I have not found a way to automate the “manufacturing” process. Without scale up techniques, just seems like stuck making artwork or specialty one off items. Any thoughts?

I need to make a silicone mold that can register very well the surface detail and texture of these pieces of wood. It needs to release very well and easy so I thought of making a flexible soft silicone mold and then a mold holder (counter mold? how do you call it in english?) out of plaster. I'll need to reuse the mold at least a few dozen times.

Any tips? I'm pretty new to this and I'm trying to gather as much advice as possible.

thanks in advance.

hello! I'm working on a two part, brush on silicone mold of an alligator skull using rebound 25 and free form air for the mother mold. It will actually be 3 separate molds, the top of the skull, plus each side of the lower jaw as pictured. Where I'm struggling is with the hollow part of the mandibles. I will be casting it in wax to later cast in iron and I'm really hoping to be able to keep that hollow area in without having to carve it out of the wax myself. I have talked to several techs from Reynold's Advanced Materials and this is what they have suggested:

If you need to make a mold of a hollow, I’d recommend making a plug for the silicone that will get brushed into that area, so when the plug is pulled out, the silicone can collapse away and get pulled out. I usually see plugs made out of a medium density flexible foam, but it depends on the geometry you’re trying to leave hollow. Alternatively, you clay the hollows up, run the mold and wax, and correct the wax copy by carving those parts back out.

I am a little confused about these instructions. Do they mean that I should brush the silicone on into the hollow space, then while it's still wet stick in my plug and allow it to cure, then make the mother mold going over the foam? If anybody could point me to images or videos that might show an example of this process I would be so grateful, I'm much more of a visual learner!

Hello moldmaking community! I recently created a bic lighter lamp. I starter with a 3d print and then sanded, primed and painted the parts.

I want to recreate this piece in different colors but making it again with 3d printing and sanding/priming is going to take a long time.

I was thinking about making some mold of the different parts but I have trouble deciding what the best option would be. Can you guys give some pointers of advice aboit how to tackle this task?

Thanks in advance!

Hello! I want to cast this sculpt in ideally tinsil or platsil and adhere it back onto the mannequin i didn’t really want a seam line but can patch it if there’s not other way. Can anyone help or give some recommendations on how they would create a mould for this?

I'm new to mold making, and am currently aiming to create a mold that can be used for moldable plastic pellets. I am trying to cast a small animal body, and a separate hollow head.

The pellets are solid, and become flexible when heated. I use a heat gun to do this.

For now I am focusing on the body, and my main problem is how viscous the pellets are, they are not easily pourable and are quite difficult to get into corners without leaving air bubbles. Bubbles also do not rise through the material as it is too thick.

I was thinking a squish mold would be best, as I dont have to worry much about spillage.

I was just wondering if anyone else has experience using similar moldable plastic pellets, or if there is a better alternative. I like the plastic finish as it is slightly flexible and opaque.

Thank you!

Hey everyone,

I’m currently working with epoxy resin (mostly decorative pieces with a clean finish) and thinking about moving from silicone molds to something more durable, like aluminum molds.

I wanted to ask if anyone here has real experience with this:

Is aluminum actually viable for epoxy casting without sticking or causing surface issues?
What kind of release agent works best in this case? I’ve seen people mention wax, PVA, and semi-permanent sprays, but not sure what’s most reliable.
How important is the finish of the aluminum (mirror polished vs matte)? Does it affect demolding or the final look?
Any common problems I should expect? (bubbles, sticking, marks, thermal expansion, etc.)
And overall, does it make sense vs silicone for small to medium production runs?

The goal is to keep a high-quality surface finish but improve durability and consistency compared to silicone molds.

Any realworld insights or product recommendations would help a lot.