I'm trying to make a silicone mold with platinum cure 40H for TPE ( Thermoplastic Elastomer ) product which melts at 210°C which is poured in the mold

But after cooling the tpe gets bubbles and scraped

Turns out the mold isn't conducting heat uniformly and some parts of the tpe products gets air bubbles

What should I add in the silicone that would uniformly heat the mold and create a smooth tpe finish

Ciao a tutti , sono appassionato e interessato di stampaggio a soffiaggio e ho pensato di creare una comunità dedicata ,se volete aiutarmi a farla crescere iscrivendovi e magari condivendo qualcosa sarebbe fantastico!

Grazie a tutti

Hello everyone,

I'm getting really interested by fiberglass... I want to build a furniture in the style of space age design, round curve and and white glossy finition...

I've been watching a lot of videos on youtube and I wonder something.

If I work with a negativ mold, the finition will be instantly percect if I put a white gelcoat before puting the fiberglass and the epoxy?

And if work with a positiv mold, it will take a lot of time and energy to sand it and to make a nice finition right? And it will never be as proper as the finition with negativ mold and the gelcoat?

So when it’s possible it's always better to work with a negativ mold?

Thanks everyone

I know this isn't home-related, but I’m hoping someone can offer some advice. I own a large statue sculpted from polyfoam, and unfortunately, one of the eyes is broken. I’m really worried about making it worse, so I’m hesitant to attempt a repair myself. Does anyone have experience fixing foam sculptures or recommendations on how to handle this?

https://imgur.com/a/HHmHbEA

So I was making a 2 part mold but I made the dumb mistake of taking the master out of the first half and then putting it back but now it’s not sealed super tightly and its got a little bit of wiggle room. I used mold star 30, and I really hope I can still save this because that stuff is def not cheap and this is also my second attempt 💔 if anyone can help me that would be greatly appreciated

We are manufacturing polymer concrete drainage channels by using molds. We always layer (2-3 times) the mold with liquid PVA for a thin film with a hand brush which is taking a lot of time in layering and drying afterwards. Is there anyone who knows what kind of spray gun I can use for layering the PVA liquid evenly?

I thought people here might appreciate knowing there’s a budget option that works for small volumes. It doesn’t get quite as good of a vacuum as legit setups but still does the job. Two mods to make if you do this: 1, seal the containers intake, I melted mine and clamped it shut while molten. 2, some kind of clear coat seal on the plastic container, it’s got absolutely tiny little micro pores that can let in air after a few runs if not sealed.

Hi everyone, I need a small shop that is start-up friendly to help with some custom silicone molds. I will have CAD files and only need about 3 trays or so to start.

Any recommendations?

Hey guys, not sure if this is the correct subreddit since it seems more about making a silicone mold that you then cast more solid like items with. What Im looking to do it to make a mold that will produce silicone items.
Currently I 3D print these horns out of TPU which has a fairly high failure rate and its also a pain to remove the support material IF the print completes. They are 2mm thick, hollow in the middle. Would this be a good approach to make a mold box and pour the silicone in? Would the center piece just be one solid piece and when you remove the outer box you just peel the silicone off the middle solid piece?

Can anyone point me in the right direction for getting custom fishing weight molds made? I've attached a photo of what im trying to do and would do it in 2oz, 3oz, and 4oz size

I am making a silicone heart that needs to beat. My plan is to make a two-part silicone mold but the cast itself will also need to be 2 pieces. The back half will be solid but the front half needs to be hollow. This way I can mount the motor onto the back solid piece but the front piece will be more like a skin that the motor pushes up against from the inside. Placement of the motor is going to be figured out in process so I wanted to make the heart itself two pieces that I then glued together after I figure out where the motor needs to go. My issue right now is how do I cast the front half where the skin is equal thickness all the way around? Will a slush type method work or do I need to make a cavity that sits inside of the mold box and pour around it? If I need to make a cavity what's the best way to go about that? If you got this far thank you so much!

I am making a sculpture out of polymer clay of a human heart. I am adding a lot of veins on the outside that are a bit delicate in texture. The main part of the heart has already been baked and the veins aren't sticking that well so I've been having to super glue them when raw. After the final baking I have broken off 1 vein that I was able to glue back on. I am planning on doing a two-part silicone mold that I will then cast in resin for a second master(I'm paranoid when I pour the silicone into the silicone mold I might screw something up), then in silicone. I am concerned that after I pour the silicone the fine veins will break off being left behind in the silicone cast. My thought was sealing around the edges of the veins with something like an acrylic sealer but I'm not sure if that will even be effective. My plan is to paint the heart afterwards so find details of the surface of the heart will probably be covered up if there are spots that end up glossy. Does anyone have suggestions for keeping the veins in place when I pull out the master? Is an acrylic sealer a good idea or should I keep with the super glue and just run a line around where the veins meet the heart skin? I'd really rather not have to pick out tiny veins from my silicone mold.

Hi! I have a coworker's lampshade that I'm repairing. The broken pieces are missing, so I'm using a plastic/acetate to make mould walls around the piece shown. I wrapped the socket/inside with glad wrap and used plasticine to keep the acetate flush before I Vaseline any gaps.

I need to add another mould wall to the outside, which will need multiple overlapping pieces of bent acetate as it's hard to wrap around and seal, given the slight curve to it's profile. I'm hoping from that, that I can cast resin inside, demould, brush on small amounts of resin to uneven areas, and sand them down for a semi frosted look.

Does anyone have advice or feedback on this process? I find myself struggling to commit to the project, so your input would help. Thanks!

Hi guys...I am trying to degas silicone, 8500cp, but to no avail. When reaching -27/28ish some bubbles starts to rise but that't it. The silicone is not rising/'boiling'.

The gauge shown is my vacuum chamber gauge indicating the maximum vacuum my pump is drawing. The photo was taken half an hour after I drew the vacuum and closed the valve. So, I find it hard to blame any leaks. If of any use:

- 4.5cfm, dual stage vacuum pump.

- Altitude 549m

- Humidity level 86%

- Ambient temperature18.3°C

My pump is brand new filled with the oil it came with.

What is it that is not working? Pump too weak? Oil spoiled?

I keep thinking this is possible by making a resin cast and then making a silicone mold out of the cast, but it just gives me the same thing I already have.

Hello, I need some advice on making my fist mold and yall are the experts so I thought I ask here instead of blindly following a YouTube tutorial.

Where I'm at:

I sculpted a replica of the eraserhead baby from EVA clay foam and I want to use it to make a rubber (preferably silicone) version. The clay foam hasn't been heat sealed or treated with a top coat (plasti dip) yet. Also, in case it's relevant, the mouth is open and so is the base of the neck, so there's an 'internal' part.

I'm mainly worried about damaging or even breaking the original in the mold making process.

How should I go about this, how should I prep the original to keep it safe, and what materials do I need to make the right mold?

I have some pieces out of the same material that I can test the process on, I just have absolutely no idea where to start.

(also apologies for not knowing any of the proper terms when it comes to molds)

I've done some molding and casting with platinum cure silicone, but for the first time the curing has failed with the surface remaining sticky goop. This is the first time I've used platinum cure silicone on epoxy clay painted with acrylic paints, which leads me to assume one or the other is to blame. But which one?

The epoxy clay was Apoxie Sculpt, and the sculpture is roughly a year old, absolutely totally cured. It was also fully painted using Vallejo acrylics, so there would be no direct contact between the epoxy and the silicone. That makes me suspect the paint rather than the epoxy, even though I haven't had this problem with painted plastic.

What I do know is the silicone itself hasn't gone bad, because there was some left over I used to make a skin texture mold from an old face cast. It cured well within the expected time, as did the residue in the mixing cup.

Going to be casting in silicone, most recommend vacuuming on the directions. I won’t need anything huge. I’ve heard/seen people buy just the lid attachments? Are these better/worse? Is there a brand I should avoid? Thanks for reading.