Prop: Shop - Molding & Casting 101: How to Make a Two Part Mold 

I've never really had the courage to try molding, but I love watching the process. I'm glad I discovered your channel. Thanks!

You can also get a silicone degasser to help prevent air bubbles getting trapped in the mold. They aren't super expensive and can really help your casts be a little more consistent.

Seriously, awesome! thanks, Bill! I'm working on a bunch of props and costumes for my sci-fi series and am binge-watching all your stuff... again...

Awesome Video! This will help a lot in improving my mold making skills! You have served as a huuuuge source of inspiration for me in my prop building. I hope one day to be half as good as you are at prop making and costuming. Thank you for all the helpful videos and inspiration!

so much better than my first mold.

Good coverage of the basics. Thanks Bill!

Perfect video all on spot easy fast without any extra talks, very helpful ! Thank you!

Just wanted to came back 2 years later and say thanks so much for these videos. I made my first 1 and 2 part molds last week and achieved almost flawless results, well after a few goes at rotocasting anyway! With out this series I highly doubt I would have even tried but with the knowledge you two have shared it was almost easy. My next adventure will be a mask so I am sure I'll be rewatching those videos again a ton before I start pouring the rebound!

Im definitely gonna make a mold of something!! Thanks for the awesome tutorials Bill!!

Superb video. Honestly. Clear and concise. Thank you.

I also wanted to say you do some great videos. Thank you very much. I've used your videos and others to help jump start my cosplay game from simple found materia costumes to creating my own stuff from scratch. I will check out that Patreon page.

For my first couple two part molds, before I actually got proper mold release, I sprayed a couple coats of crystal clear coat to act as a barrier between the silicone halves. I think Frank talks about that on the Tested two part mold lightsaber video. Works pretty well in a pinch. And a good alternative.

very nice video, I wanna start doing this at some point, with my twin kids (they're 3.5 years at the moment...). Thanks for sharing, and Keep on trucking ! (from France)

man this series is a real god send Bill!

Great video, as always, thanks Bill.

Lots of good information on this episode. Thanks for sharing this!

many thanks....you explained this great....been doing 1 part molds for a year or so, but im going to need a 2 part soon.

Alway the best videos. You should come back and revise this or updated the videos but can mess with the classic.

Un excelente video, me encanta tu canal 👍

Well done videos... thanks for sharing...

amazing series! (: so helpful! :D

great tutorial. very clear

One thing I discovered is that after the first part, you can draw around the outside with a sharpie so you can see where the two parts come apart. Either that or tint each part.

Absolutely love this video thank you for sharing!

Super educational as usual, thanks and keep it up! :D

Watching you use the tools to smooth the clay from the edges was oddly satisfying :)

Really nice!

Flying fantastic, thank you!

Omg that came out sooo good!!! Better than the original master

+Punished Props would a mini vibrating table help remove the bubbles from your molds. Much like they have vibration sticks in large construction to fill in the gaps and remove air bubbles use an old cell phone vibrator attached to a "floating" board to create a mini vibration for a few min

here is an unorthodox question (it may be a pretty silly one too).... if you were working with a smaller or medium sized mold, what would happen if you poured the resin into your mold, and then put the mold in the degassing chamber? would this help get air bubbles that are trapped in details on the piece? or would it cause some sort of insane reaction? i.e. damaging the mold itself, or actually adding more bubbles to the cast piece. I never see anyone do it, so i'm just curious if it would even work or what would happen if you did it. Loving the series so far, extremely helpful! looking forward to the next episode! cheers!

Check out plaster jackets for the moulds. Saves a fortune on the silicone.

now I know where I went wrong, thx Bill!!

have you thought about putting together a small kit (i.e. your logo) for people who want to try casting but are too nervous to buy the expensive silicon

So good

Bill I noticed when shaking the mold for bubbles it can be messy. I know a tool fairly cheap . Buffalo Dental Lab Stone Mixer Vibrator No.1A Its a Vibrator for making stone molds or casts of peoples teeth. Being the stone can be a bit tough to work with IE bubble removal this tool would work well with Silicone/Resin materials as well.

Heya! Great tutorial, can't wait to try it out! I have a Question though.. If you make the master object out of clay, how does that work? I assume you can't really add clay to a clay master object, because it'll stick and you will lose detail.

I've seen many people using legos to make walls for their molds, any thought about this method Bill? Your videos help a lot, even in the other side of the ocean, thank u so much from France!

So here's a thought. Since NSP can melt, would it be a viable technique to heat some up until it's runny, and then pour it around your master for a perfect 90 degree seam clay base?

Awesome

Very educational. I'm enjoying this series and can't wait to try the two part mold on my pieces when they are finished. Quick question, which type of molding would be best for a halo/space marine helmet?

Does it also work if you use plaster of Paris instead of resin for the actual piece????

Thanks u this helps

Hello bill i was curious about what type of materials you use for making model masters?

Hey Bill and Brit ! Could you guys please post a link to files you used to 3d print that NN-44 blaster? Would be super happy to print it and follow along with you :)

Can you use rebound 25 for this method? And do you guys have any videos that could help me figure out the best way to make a mold of an axe head with a hole through the middle of it for the wooden handle to go in?

whats your original props made of?

thank you for that! really helpful. I've made a skyrim dragon priest mask master to make a first ever mold with you because I think you have a really good interpretation and skills :D Few questions I have :D I need to use mold release or can I use vaseline for example. By the way if you do rondo slush directly in paper model you can easily separate paper from hardened bondo and resin mixture if you brush vaseline on the paper before slush... maybe you already knew that :P And also do you know what is the biggest difference between polyurethane and polymer? I've checked in stores around my home and I could only found Polymer resins... but from the description it sounded similar to polyurethane. Thank you for videos... I Can not wait for another video to come!!

hello, taking on a bit of a hobby project, molding a vaporizer mod box. Its two pieces, a this cover that slides into notches, and the bottom have that will have the battery sled and all the electronic components. The bottom half is whats giving me pause. My plan is to mold it with the hollow part facing up, with a clay cylinder added to what is the left side to pour in resin to the mold. Does that sound feasible? Open question to any one that takes a look at this

Hi Bill. what is that piece of mdf on Reys' mold for? I assume in the end, it consumes more resin? What is the benefit? thanks a lot for the video!!! *-)

Can the final cast be drilled? How hard is the resin part after cooling?

Can you post a link where you can get your tools like the razor blade do you use

Could you use foam board to make your box for your mold? The foam board you can buy at office supply stores that you would use as a display board.

I'm loving this series! Super informative. Have you tried any other alternatives for making molds (other than silicone)? I've seen some smaller casts using brands like Composimold, but I'm not sure how well it would work with resin casts of a larger prop

If the piece has a front (showing) and back, then which side do you recommend to do first?

Just wondering, once you've poured your resin into the mold is it worth putting it in to the vacuum chamber. Will it make any difference with the bubbles?

How effective is this technique for casting large objects like a sword? what tips would you suggest for when a mold becomes particularly large?

How do you make the master though? What are good materials to make them out of like guns or weapons? Or pieces for armor?

Is there a real reason for casting a prop if you are only intending to do a 1 off? I'm working on a good solid MDF gun, but is there a benefit to casting it in resin for just me? Keep up the great vids!

A question unrelated tot mold making. Do you use some sort of lighting rig when recording video, or do you just use whatever light you have available in your shop?

are there any other materials i can poor into the mold instead of urethane resin

Hello hello, I'm reviewing your whole casting mood video, because I'm starting to do a lot of casting. My question is, is it mandatory for a sword (mines are warglaives wow), to make from the first mold literally half of my sword? To avoid the seam, I mean, if it is better if the seam is on the side blade and there is no problem sanding it, what about the edge? Thank you already for your answer because Cast and Mold is stressful the first times

There are a lot of Resin to choose from as you mentioned. To make a gun mold that will be subjected to contact with approximately 330 degree Kydex, is there a preferred resin to handle this? Thanks a bunch!

having a bit of a panic attack cause my mold won't split apart.... how long did it take pry the two parts apart? I've been at it for like an hour (i used ease release 200 on mold star 30 silicone)

Loving the series so far. Your style is great and it's obvious you've put a hell of a lot of work into the videos. One question, when you say do a little dance is there one you recommend like say the cha cha or would a two step do. Just asking.....

Can you reuse the mold for other projects, get it back to liquid or is the mold trash?

If I make a prop out of EVA Foam can I make a mold out of it right away ? Or does it need to be prepared in some first.

can we do this for rectangular bonsai pots ? maje a vid pls dude

Which silicone do you use ???

Vc usou resina epoxi?

I really wish you did a "you will need" section at the start

Es silicona de caucho???

Bill thanks for this awesome video! I'm looking into making my first 2 part silicone mold - however I have to make the master of the object myself. Do you think making it out of FIMO modeling clay would work, or would you suggest anther material?

its the vents that are stumping me, im going to be moulding a face hugger, im guessing 2 part but i have no clue where to place the vents or wether im better off dismantling my sculpture and doing 3 seperate ones, legs, body, tail.

Mission accomplished I am inspired! I want to cast a statue I've made. If i don't have a degasser will the finished product be ugly and full of bubbles? It is a fine object with lots of small details and smooth skin surfaces ect.

are you going to do a trial on how to cast a helmet

Nice instructive videos. Question, What wet clay do you recommend, brand? Where to get it?

Frank Ippolitto doppelganger!

Late comment, but what if you've made your master out of plasteline clay? How do go about making the clay 1st part of the mould?

Can you pour silicone rubber liquid over polyurethane rubber items? I don't want them to stick together.

What if your master is a clay sculpt?

so im trying to make replicas of the exotic sword crystals in destiny out of resin and siliconnmold, what should i use for the master object? clay?

Greetings from the UK. Love your videos, I'm new to this and keen to get my first silicone mold project on the go. One question - does the urethane casting material suffer from captive bubbles in the same way the silicone does, and does it need vaccing or pouring from a height? Cheers

What about if you have inner cavity that need to be just as accurate as the outside? Would primed wood be ok to set into and extend thru a 2 part mold?

Any thoughts on offering workshops anytime in the future? I know I would pay money to come learn on a weekend or something. I think I saw Artyfakes offers that kind of thing but I sure cant fly to Europe. Seattle would be much more affordable.

hey bill can you make a video about the tested box figures i would like to se that sorry for my bad english

Thank you for sharing this information with us. Extremely informative. I have a question, if anyone knows the answer. I need to make a 2 piece mold to cast a car part that is made of rubber. I need to know what needs to be done to the master to insure the silicone will not stick to it? I was told I could coat it with Vaseline before pouring the silicone, but wondering if this is the only option, or if there are other methods? I will be using polyurethane for the copy.

You're like the Leonardo da Vinci of the future.

Punished Props Could i sand away the seem line to smooth or to not that noticeable?

I was so happy when you answered my question in the Q&A video :3 So thank you! .. But here I am, with another question xD (If I get annoying, just kick me :P) I want to make a two part mold for these big chains for a World of Warcraft Tier 13 Hunter outfit. I figured it probably will be best to make only half of a chain link, so I can still link them together to .. well.. become a chain :P Now if I would want a full set of chains I would need to cast A LOT of copies in this mold. So my question is: Is it possible to make a mold where I can cast several of them at the same time? (I think I saw one in the intro of this video, the blue mold with the tubes for.. I think it was the District 9 gun) I'm not sure if there is anything different about doing that or something I need to be careful of. Thanks in advance again! :D

can you use silicone in the cast to get a rubbery mold? you probably have to use mold release on it first though right?

Is there anyway to help the pour viscosity of older resin? When I tried to pour resin into my mold it cures faster then i can get it into the mold. It isn't even a very large mold. Also I am curious who sells that curved hobby knife?

how would you hide the seams after removing the cast from the mold?

New to mould making. Cant seem to find anywhere in the uk who sells smooth on.... Which is what everyone one youtube seems to use. Is there an alternative that i can get in the uk?

hello i have a mechanical object that has lines that act as gaps to the inside what is the best way to fill the holes on something? I want to mold an airsoft pistol if that helps to make a mold for kydex. But am unsure if i should maybe use clay inside the gaps? or tape it off? any tips or advice as i dont want to ruin the pistol im trying to mold but if it gets a little gummy or stained im ok with it. Thank you!

Is there any alternative to mold release for silicone on silicone, cause I'm just going to make the one two part mold and I see it a little pointless to buy the spray and pay for shipping.also do I have to treat bondo with anything before pouring silicone on it.

also, what would be the best silicone mold for a palm sized extremely reflective gold plated figurine?

I am casting, not with resin, but with more silicone in my silicone two part mold. Do I still use baby powder like how it is used in the video at 5:11 or do I just add more Mann Ease Release to both parts of my mold?

Urethane Resin is good with Latex molds!? Thanks

how would you prepare the mold if you need to have an internal thread in your mold?