How to Make Silicone Dice Molds!

Here's a step by step walkthrough of how I make the silicone molds I use for my dice! It's a bit of a process, for sure.
Materials Used:
Lego
Packing Tape
Dice (Or Dice Masters. Mine are from Revel Broker, who appear to only do orders through their patreon now: / revelbroker )
99.9% Rubbing alcohol (www.amazon.com...)
Q-tips
A Craft Knife
Petroleum Jelly
Silicone (I use Smooth-on's Mold Star 15 Slow. A trial sized bottle can be found here: www.amazon.com...)
Nitrile Gloves (www.amazon.com...)
Patreon: / alchemistsattic
Twitch Streams: / humanlizaster
Stream VODs: / @humanlizastervods8806
My Shop: www.alchemists...
Discord: / discord

[@metehan1761]

The chosen music, the style of narration and the voice.... I think I fell in love.♥

[@tonyabrown7855]

What an amazing tutorial! I was struggling so hard to figure out how to make a mold for mardi gras throws I'm working on. I had seen people making resin dice and figured I needed the same type of mold. Found your video. I am beyond grateful for technique!

[@alchemistsattic]

Happy to help! Hope your project goes well :)

[@TheMercurialAlchemist]

I absolutely love the idea of using legos for creating molds, I really like the square shape of them and I've been having trouble thinking of a way to make a better mold for my dice boxes and I think that idea is perfect, thanks!

[@alchemistsattic]

I hope it works well for you!

[@emelie3602]

Same! The lego idea is genius

[@johnobrien7626]

Awesome video :) My players are looking for unique dice and making dice for them is definitely on the cards now.

[@alchemistsattic]

That'd be super cool! Dice are a lot of fun to make, and it's really fun making them based on things like characters or for friends :)

[@crazykimber85]

This helped so much. Thank you!

[@sirsparkalot2661]

Not sure if my last comment got thru….you are a genius..Gives me an excuse to play with Legos. Could you not use Legos, instead of packing tape, to make the lids? Just curious. Thanks.

[@sirsparkalot2661]

You are a genius! Gives me an excuse to play with Legos. Quick question. When you go to make the lids, could you not just use Legos again? Could you not build it up just two, or three brick higher? Just curious. Thanks.

[@alchemistsattic]

I don't see why not- It'd be worth a try! The reason I went for the tape is because it's faster than putting the lego forms together, but I suppose if you put something in to act as keys and then removed them before adding the bricks, you wouldn't even need to take the forms apart before doing the lids.

[@timefire2586]

Ohhh, these are really cool molds!! I'm just starting to get into working with resin and I've been wanting to make dice with it for a bit now, but I haven't been sure on what molds to use. These seem to be working quite well and you were able to get the leftover resin off quite easily in one of your other videos, so I think I'm going to try these for myself

[@alchemistsattic]

Awesome, I hope it works out well for you! I'd love to hear how it goes :)

[@timefire2586]

@@alchemistsattic It took me a while, but today I finally did the first layer of silicone! So far everything went pretty well. At least aside from the fact that I didn't have enough legos to make squares for all my dice (I ended up making a long row, which left me with two (2) blocks to spare) I'll let that cure for a day or two (the silicone's supposed to cure pretty fast, but better save than sorry) and then hope that my mold release is going to work

[@alchemistsattic]

@@timefire2586 I know a lot of people make "slab" molds where all the dice are in one mold together, so I bet that'll work out just fine :). Good luck with the lids, I hope it works out for you!

[@ABaumstumpf]

Nice and easy to follow video. But i will say: Silicon does not really benefit much from pressure while curing, and depending on the exact type it can lead to faster degradation as it can not hold as much gas dissolved as resin. When you look at professional mold-makers they will degas the silicone in a vacuum chamber but let it cure under normal atmosphere. Only for the resin (and there not for all) they will put them in a pressure pot. There is one situation were pressure can help: If your silicone has a lot of bubbles. You do NOT want to be in that situation. The problem here is that while the mold might look fine normally, when put under pressure for the resin-cure the bubble will also be compressed which can lead to surface-dents and deformations. In this case if you cure the silicone with the same pressure the bubbles will expand when outside, but when curing resin the pressure is high again and the bubbles get smaller to the same undistorted form it had during pressure curing. But again that is only when you already have way too much air in your mold.

[@mrjrm0868]

Hi Liz. I'm glad I found this tutorial. So simple. How many Legos did you use per die? I think I counted 18.

[@alchemistsattic]

Oh, I never really counted... I usually just try to leave a quarter inch of space around the die, however many dice that takes. Let me think, though... I think it's 24 of the 4x2 blocks for most of them? 3 layers of 8 lego each? It's a few more for the d20s and d12s which I make slightly larger molds for.

[@the_og_claudiva]

I love your dice videos as they make everything look casual, easy and fun. As if! :) I've probably tried every technique/mold shape on KZbin for making molds, but I'm never happy with the results. The big question for me is: how are your dice coming out of the mold so cleanly? I usually end up with voids and/or bubbles along the edges of the faces with this type of mold. I've also tried a number of designs with sprues and offset face plugs, but I hate using them and still end up with voids! How are you not? I use a vacuum chamber after mixing my resin to remove bubbles, and a pressure pot to compress any still in there after pouring, but I still get voids! Any tips for me? Thanks!

[@alchemistsattic]

Are the bubbles part of the mold, or just in the resin?

[@the_og_claudiva]

Just the resin. I’ve switched over to bbdino super elastic silicone, and don’t need to to degas or cure under pressure with it. It’s also cheaper, and cures in 4 hours. But it didn’t fix my resin issues!

[@alchemistsattic]

@@the_og_claudiva Have you tried using a different kind of resin? maybe it's the resin itself? Seems odd, though, that even with a pressure pot you're getting a lot of bubbles.

[@hobieslittlesibling]

This might be a dumb question, but do pressure cookers work as pressure pots. I mean setting it to pressure rather than pressure+heat

[@alchemistsattic]

I'm not %100 sure how pressure cookers work. Don't pressure cookers usually use steam? Moisture might cause problems, and I'm not sure if you'd want to leave the pressure cooker going for that long anyway. Maybe someone else can chime in with more info, though.

[@danking7460]

How long does a mold like this last? I see a lot in the background and was wondering if it's just different type of die of is it because they break fast?

[@alchemistsattic]

Mostly I make a bunch because I want to be able to make multiple sets at once (or a batch of 9 d20s like I'm currently working on, lol), and because I like having options for molds with either the highest face at the top or at the bottom depending on the design I want to do. I do also have quite a few different designs of dice, including my normal 8 piece set, an extra different shape of d4, pipped d6s, fate dice, dice blanks, vampire the masquerade dice, jumbo dice, and jumbo dice blanks. They honestly last me quite a while (not sure on an exact timeframe, but I've had a few of these molds for probably a couple years now and they're a little beat up and not quite as shiny, but still usable.)

[@evanpennock1301]

I'm curious if you have experience with casting dice with rounded edges and if that makes a big difference in the mold making?

[@alchemistsattic]

I'm afraid I don't have much experience in that area, no. You might join my discord and ask there, though? People there might have some more experience with round-edged dice. (Link to discord in video description)

[@k5K5x]

I saw people use baby powder instead of petroleum jelly or vaseline. Don't know is it works better though

[@alchemistsattic]

I've heard that before, too, although I haven't tried it myself. Could be worth a try at some point :)

[@craigaonifall]

couldn't you re-add to the lego mold and just stack higher to make the lid and i would add corner shape lego at the bottom of the mold to make the registery keys

[@alchemistsattic]

That's an interesting idea! Perhaps if I had added something when I poured to add the keys instead of having to cut them after pouring.

[@IcsulX]

How did you prevent Mold Star silicone from reacting with the masters and not curing properly? Platinum based silicone usually reacts with 3D printed masters.

[@alchemistsattic]

I'm honestly as baffled as you are. They place I got my masters from apparently uses some sort of non-reactive resin in their printers. I'm sure I'd have so much trouble if I tried to make molds with masters I printed myself.

[@the_og_claudiva]

@@alchemistsattic, actually dice masters are *usually* cast in the same type of epoxy resin you're using, not 3d printed. Silicone cure inhibition only happens with 3d printed resin, as it has sulfur in it. I can usually get around this by sanding and polishing the heck out of them and then surface treating them with some nasty chemicals. That's way too labor intensive for each set of masters, so they mold them similarly to what you're doing here.

[@alchemistsattic]

@@the_og_claudiva I know a lot of manufactured dice are cast much the same as my dice, but I'm talking about custom masters (For example I had my shop logo put on my d20), which are a bit more unique. At least in the case of my masters, I know they were 3d printed, because I follow the people who created them on social media and Patreon.

[@the_og_claudiva]

Got it! And you use platinum cure silicone? You can process 3d prints under UV for a few hours, followed by a few hours under heat, but that makes them more brittle. You can also treat them with naphtha, but it’s nasty. Other than those, the only thing you can do is wait a few weeks, but then they’ll be fine to mold.

[@alchemistsattic]

@@the_og_claudiva Yep, I use platinum cure. The place I got my masters from uses some sort of UV resin that doesn't seem to react with the silicone :). I have heard that letting 3D prints sit for a while helps a bunch with cure inhibition as well, yeah.

[@TheOlminiartureworkshop]

Does it have to be a specific type of silicone

[@alchemistsattic]

Depends on what you're trying to do, and what your masters are made out of. Different kinds of silicone have different pros and cons. Some silicones react poorly with some 3d printed masters, there are different hardnesses which may make a mold that is so soft it doesn't hold shape, or so hard that it's difficult to remove the dice. Ultimately, a lot of it comes down to personal preference.

[@TheOlminiartureworkshop]

@@alchemistsattic ok. I was just curious. Thanks