Molding Or Casting? Which is it?

Molding and Casting are words people use interchangeably, leading to much confusion. In this video I explain the similarities and differences between molding and casting and how to use the words correctly.
00.00 Good morning!
00.05 Let's talk about two words: molding and casting
00:17 The point to molding and casting is to make a copy of an object.
00:44 A mold is a container with a specific shape that, when filled, transfers it's shape to the casting medium.
01:27 Silicone rubber molds are flexible molds.
02:18 Other kinds of molds are rigid such as wax or fiberglass molds.
02:45 Molds are also called Tools. There are flexible tools and rigid tools. That's why you will see molding rubber sometimes referred to as tooling rubber.
03:50 Rigid molds can't have any undercuts that would lock the casting into the mold.
04:00 You must design models for rigid molds that take into consideration the direction that the mold will be pulled open.
05:20 The word casting is both a verb and a noun. When you are pouring resin into a mold you are casting. The object you take out of the mold is also a casting.
06:00 There are hollow castings, open back castings and solid castings.
06:20 When properly made, hollow castings have even wall thickness and smooth interior wall surfaces.
07:30 Another reason for the confusion is that molding and casting are essentially the same thing.
08:25 The thing you are copying goes by many names: The Pattern, Model, Master, Sculpture, Item, Object and Original
08:56 The pattern must be oriented in the Mold Case. The mold case is the container that you fill with rubber around the pattern to create the mold.
09:38 When making a mold you are pouring a liquid into a container just like you do when making a casting. So molding and casting are the same activity. When discussing these things its easy for people to get confused.
10:30 It's essential to pour the mold rubber into the case properly; from the bottom up!
11:30 Another reason molding and casting are the same is in both cases you have to move the air out of the way to fill the container with rubber or resin. the way we do that is using gravity to fill the container and let the material push the air out above it as it rises. if you trap air against the pattern you will create voids in the mold.
12:15 Pressure pots will eliminate small bubble but they will not remove big ones.
13:25 Molding and casting is all about making a perfect casting by pouring in the material and removing all of the air in the container. The best way to do that is by placing air vents correctly on the model to allow the air to escape.
15:06 Let me know if this video is helpful to you and be sure to send me any questions or ideas you have for future videos.

[@leifkicker]

I've been molding and casting for over ten years and I learned something from this video. I wish I would have had all the information you've been sharing back then! Your videos have all been on point, interesting thumbnails, catchy titles. Love it! Please keep them coming.

[@Perry-the-platypuss.]

Thank you it was the best explanation I got for this topic 🧠🙌🙌👍

[@AncientHermit]

I've gone from child amateur model maker to pro model maker, to Quality Controller for a global injection moulded kit maker in my life time, then did 3d model making for a decade or two. I am now retired and looking at tinkering (for fun) with casting in resin or silicon, perhaps. I say you were dead right to make this video, because all the things I have learned so far tell me that to have a chance of a success on any project, you absolutely must understand the basics, I do not mean learn to repeat the industry jargon on demand, I mean understand. This is a solid first step for anyone to take. Nice job Sir. Be well.😉

[@arda_ufukk]

I am a mechanical engineering student and i was confused until this video. Thank you

[@maryarmstrong687]

Im a beginner just starting out and understand why you are demonstrating this. Thank You Ive learned a great lesson here that I will apply every time.

[@KristonAbbott]

I’ll always give a thumbs up to a video that features the word nomenclature! Informative and educational as always Robert.

[@Pteromandias]

“Is it too elementary for most people?” It might be. But I’m at an elementary level so I enjoy these kinds of videos.

[@humblehombre9904]

Thank you again, Bob. You are so friendly and informative. You are an excellent teacher.

[@vmitradkwondofytr480]

I'm molding and casting for my thesis, really helpful at explaining the jargon - thank you!

[@Lunatheia]

This has been extremely useful. Sometimes it’s good to go back to basics even for those who’ve been doing it for a long time. I was having this same irritation with the lingo the other day and this clears it up nicely. Thanks 😊

[@Arigal3]

you are a master of the craft, im from colombia and im here learning so much from you thank you very much

[@levinebette15]

Yes! helpful! How you need to plan for vents for pour! This is the stuff no one wants to learn, but should!

[@RobertTolone]

Yeah, proper venting is essential.

[@hombrebala_toys]

I love your videos Robert. Your explanations are clear and you know what you´re talking about because you talk from pure experience and that´s something ivaluable. You´re the teacher! Keep on shinning light on the cast/mold process! Greetings from Spain!

[@RobertTolone]

Thanks Antonio!

[@Melscreativearts]

Thank you for clarifying! I appreciate all of your tutorials so much! When asking at an art shop about castings and molds, ive had confusing conversations with the workers there....as in they didn’t know what materials I was asking for. Got it now!

[@RobertTolone]

I’m still feeling my way here, trying to see what would be most helpful to the viewers. Thanks so much for your comment!

[@naldomination]

Thank you Robert. This is very helpful. Wish you could also discuss your tools and equipment please. The fancy ones up to the most simple and necessary and also what one will need to start a small casting workshop. Thanks again!

[@karimosama5541]

Your presentation is really amazing.

[@RobertTolone]

I appreciate that Karim. Thanks!

[@Toystorations]

I had a title for you to work with, for a future video. I don't think I've seen you do it yet, and I think it has potential to reach a wide audience. "6 Things You MUST Know Before Making Your First Silicone Mold" I think would benefit people a lot. Maybe not 6, but whichever number you think hits all the points you need to cover basic stuff. Each video you produce has little tips and tricks in it to showcase different challenges, but laying out a small list of basic things everyone will fight on their first pour is I think what I'm missing from you while I watch through your catalog of videos. For me, from watching, I think measuring the silicone as carefully as possible is an important thing to know, knowing what materials won't let silicone set up is important to know, knowing how to orient the model I'm working on for a successful pour (and how to cut the mold for a successful cast), and how to prep the model for a successful pour (sprues, vents, funnels, where to put them, etc.) and knowing how to pick the type of mold (one part, two part, flat back, etc.) for my project is also important. Those are the things I can think of, being in the process of doing my first pour right now. Surely I've missed some, and I think the ones I missed are likely the ones that people need to hear, and the ones that deserve a video. People starting out, or those who have been inspired to try from watching you, will definitely watch that video and gain something from it, but also those who have been in the hobby or business for a while and think they have a good grasp of things will also watch it to see if they agree with your list. You can also talk about and link to videos in the description that show you facing the challenges you are glossing over, so people who are struggling with each step can really see you struggle with it and overcome it as well.

[@irenerichardson2383]

I found a lovely fossil that has formed from an open clam filling with mud which left an imprint of the interior of the animal. Couldn't decide whether mold or cast. THANK YOU!

[@Daniel-vp2on]

I've never made a single mold but I'm interested in starting and I'm sure I would've gotten bubbles in my castings one or all of those ways you mentioned had I not watched this video. You just saved me a lot of time, effort, and frustration. Thank you.

[@RobertTolone]

I’m very glad you find my videos helpful Daniel!

[@gabrielsequeira2347]

Thank you so much, this clears up what a mold and cast is. I've never cast before and I've got to for a 3D project I have so this was really informative thanks

[@maniestacio9245]

This was a masterful explanation! Thank you so much for sharing your expertise with us. You’re clearly so knowledgeable and passionate about your craft! 🙏 🤗

[@calv46]

I’m new to sculpting/molding/casting and I usually have difficulty in finding the place I need to put my vents when molding my pieces and usually end up with a little bit of bubble in my castings (can’t afford a pressure chamber). Your videos have been very helpful to me. I love your channel! Thanks, Robert!! :)

[@RobertTolone]

You can make bubble-free castings even without pressure pots. Placing the vents properly will do the trick. Rocking, tilting or vibrating the mold can help too. Be sure to keep urethane resins away from moisture by tightly capping the bottles. Thanks for watching!

[@MonicaRayner-rl4xb]

Thank you so much! Super informative and great for helping this noobie!

[@onkarkitekt]

🥇This was helpful for a project I'm planning 🙌

[@dianeharris2687]

You explained everything in an easy-to-grasp manner. Thanks.

[@RobertTolone]

Diane Harris Thanks Diane!

[@YanniCooper]

I'd love to see you go over some of the other jargon that is commonly used! A lot of the time we can make a pretty good guess, especially when you use it in context, but I doubt many people go looking up "undercut" especially as that's a more obvious one from context. Before this video I thought I knew what "pull" meant, but obviously it has a different connotation for molding/casting than for magnets, tug of war, or skeet shooting. And of course one of the big things is that in any industry, once you're familiar with it the jargon becomes second nature and you barely notice when you say it. I'm big into the miniature wargaming scene, and one bit of jargon that I'm fairly certain I (and almost everyone else) gets wrong is "Sprue"... I think what we call the sprue is actually called the tree in the casting world, and the sprue is just the bit where the material enters the tree.

[@h7opolo]

i grew up without a grandad. i love you so much, ill adopt you.

[@RobertTolone]

You like the guy on the channel. Once you get to know the real me - probably not so much!

[@h7opolo]

@@RobertTolone true sentiment. i respect that. you know how fans get.

[@BIGJIM1934]

I'm addicted to your videos! Very informative and you're a quick witt to boot! The only thing I would add is that vacuum chambers and pressure pots should be used in conjunction with one another. If you don't vacuum your rubber and make a mold with air bubbles just below the surface, you could end up forcing resin into all those tiny air bubbles. Keep up the good work. And on a side note...how does one get one of those tasmanian devil castings?

[@MRNIIK]

Robert this was really eloquent and helpful! You may think it was too elementary, but what you did here that I really liked is simplify the philosophy down to "get the air out of the way". I think framing it this way makes it really clear! This video serves as a fundamental rule of thumb that will help many people in trickier mould/cast designing situations not make silly decisions.

[@RobertTolone]

Really appreciate your feedback. That’s exactly what I was hoping the video would do. Thanks!

[@oo70vd]

Thank you! It's very helpful. 👍

[@mattmoore1311]

I spent a good part of my life as a commercial/industrial carpenter. To add to the terminology confusion, concrete workers refer to the mold as a "form". You'll get razzed if you call it a mold. For us, we call any sort a of core such as a window or door opening a "buck", smaller cores are called box outs or block outs. That's just scratching the surface of the jargon by concrete carpenters. Thanks for posting these videos.

[@RobertTolone]

Every trade has it’s own jargon in the molding and casting world. Foundry jargon is different than resin casters, jewelers, etc.

[@Gtown1777]

Great info, thanks! I would appreciate a lesson on sprue placement and your thought process and approach to this topic. Regards :)

[@RobertTolone]

I am beginning an ongoing series next week on how to set up challenging pieces for mold making. It will cover how to position the model in the mold case, the size and position of the inlet funnel and sprue and the location of the air vents. I hope you will find it useful!

[@k.p.2706]

Thank you, Robert. Your video helped me tremendously today. I'm currently working on my Halloween costume and trying something new. Your clarification on terms was a great refresher!

[@punkeasy]

Fantastic information.

[@eldergodscreations]

This was very helpful. Thank you.

[@DudeBoerGaming]

Thank you for the video...The technical aspect of it is great! My 2c is to make more videos going in-depth into the detail. One cool trick I have proudly learned myself (from your inspiration to do more tests) is to create a wheel model where I cast the inside of the wheel with plastic and the tyre of the wheel in foam but all in one final piece. One mold is used to create the wheel, then the casted wheel is placed in the second mold, which is then casted in foam (or whatever the tyre material needs to be made of).

[@RobertTolone]

That's a subject I plan to cover in a future video- potting a casting (or other object) in a mold then casting resin around it. Should be fun! Thanks for sharing.

[@n.m9917]

I appreciate your time and information.. thank you

[@RobertTolone]

Thanks for watching!

[@akabeka2352]

Is very very helpful thank you so much.

[@jenchiwu]

Great video for the clarification. Fantastic and thank you..😊

[@nkinacho]

VERY HELPFUL!!!

[@roger.agburn]

Hi Robert. I like the video, it's basic, but as I see in the comments, it's not too basic. If someone has watched all your videos, some parts orcourse are a bit repetitive. But most of the time it's good to have some kind of summary on certain topics after a while and this video fits very well into this section.

[@RobertTolone]

Thanks Roger!

[@cryptology3975]

I like your illustration of what creates air pockets and/or bubbles in molds and castings. I think it would be interesting to see these ideas in a practical manner! Perhaps molding and casting the same object twice, once with and once without proper pouring and venting? Maybe you could cut a mold in half and seal it with a sheet of acrylic so we can see what's happening inside while you pour?

[@RobertTolone]

Clear front panels on my molds is a great improvement that I will implement in the new year. I did it once before in this video: kzbin.info/www/bejne/m2a7fKeujbWrq8U

[@itsio7188]

Thank you. Very helpful. I have watched many of your videos so far. Do you have any videos or tips on what kind of rubber and resin to purchase? Some guidance if you will 😆 . Your videos are becoming exciting with every one I watch.

[@RobertTolone]

I cast mostly urethane resin in tin-based silicone molds. There are many manufacturers and a great many resins and rubbers. It’s hard for me to recommend specific ones because they must match the needs of your projects. Best idea would be to contact a supplier such as Smooth On or Silpak and describe the objects you are making. They will be able to recommend products for your project.

[@itsio7188]

@@RobertTolone I thank you very much for your reply!

[@rlwhite55]

This does help a lot! Thanks for the clarity!

[@RobertTolone]

rlwhite55 Thanks so much for watching!

[@redshadow3095]

your videos always help, any one new to this would have value in this it is confusing when any one is new and still you can mix up a word to a client and have to re-explain to them the process again. Keep making them, you should also link tools you use in every description and maybe get affiliate links cause i would be happy to buy a few things to send something back to you so you can keep making them and have it not cost you out of your pocket :D

[@RobertTolone]

Thanks for your input. It’s so helpful to know what topics to cover.

[@CliffRoth]

Very informative. Perhaps add something about mother molds.

[@RobertTolone]

Cliff Roth Thanks for the suggestion Cliff. I have covered them a little in my rotational casting videos. kzbin.info/aero/PLIy8UDigJ_ylz1wHqv_WUJZmArXjBg0zm But they’re worthy of a much more in-depth exploration.

[@lifeholdstrategic]

Great explanations! Thank you for this, very helpful.

[@RobertTolone]

You’re welcome, thanks for watching!

[@paulhayton3423]

Planning is everything..thank you!

[@RobertTolone]

Thanks Paul!

[@MsZzzipper]

This is soooo helpful!! Not elementary at all!

[@RobertTolone]

Thanks Lee-Ann!

[@ArcticFlies56]

Bob, for people just starting out, this video should be the first video they watch. For people who are trying to navigate a new hobby, maybe a business or to make copies of artifacts they want to keep, this is very important. The problem here is the nomenclature of the parts. Maybe someone should write a new dictionary for all these parts so that there won’t be so much confusion. Like the proverbial duck. If it looks like a duck, walks like a duck and sounds like a duck, then it’s probably a duck. Like General Patton was quoted as saying when addressing the British, we’re similar people separated by a common language.

[@msredcorvetteme2463]

Do u have a video of making a two part mold? A front and a back such as making a doll mold. Thank you for your time. Love your videos!

[@treblam1]

Excellent and informative as usual!!

[@RobertTolone]

Albert Madril Thanks Albert!

[@AsainNerdfighter]

This was so insightful, thank you!

[@RobertTolone]

Glad you found it useful. Thanks for watching!

[@edwardmurray2284]

I'm more advanced than this in most ways, but not all, because I use a different kind of mold and casting process. It's still enjoyable to watch, and probably informative to a lot of viewers. It's also good to see other other people's perspectives and strategies. Learn till you die, that's my philosophy. Have you considered doing Patreon?

[@RobertTolone]

My focus has been on learning to make videos that are useful to people. Now that the channel is growing I will consider options for making it pay for itself. We’ll see how it goes!

[@edwardmurray2284]

@@RobertTolone I understand. The information that you are giving is very helpful, and I will make sure to try to return the favor with feedback. From what I've seen, certain fields seem to be much more lucrative than others on Patreon. For some reason, Miniature painters make a killing... Sculptors and others just make pocket change, but Patreon seems to be growing. There is a guy named Crafsman who puts out really quality stuff on both KZbin and Patreon and he does very well with an increasing audience.

[@ERP444]

Your amazing dude!!!

[@linga3240]

Thank you sir , You cleared what i had confusion about cast and mould. A container used to get specific shape and size by pouring molten material and get when it solidified, is this the meaning of mould, cast, pattern,form, cavity, die,. Right sir

[@scaredycats2794]

Very helpful! Your video was the only one I could find on it so clear! Would there be a way to do one with undercuts?

[@RobertTolone]

Undercuts are never a problem with rubber molds because the mold flexes when the casting is removed. Undercut are a serious concern when both the mold and the casting are rigid.

[@richards8291]

new to this video was awesome thanks for your time

[@RobertTolone]

Thanks for wanting Richard!

[@DudeBoerGaming]

Would love to see how you make a copy of a small gear with many teeth. I keep running into problems with bubbles. Creating an open-top mold as an alternative works sortof (for flat gears) but many casts flop because of overfilling, which in turn means every gear teeth needs to be finished off manually.

[@RobertTolone]

Gears are very difficult because you must vent the teeth. Also the casting will shrink a tiny amount when it cures so there are dimension issues if the gear must fit into an existing assembly. On top of that there is the question of whether to cast or bore the shaft hole in the gear. Holding tolerances in castings is extremely difficult; that's why most machine parts (such as an engine block) are rough cast then milled to final size.

[@brianmosher4053]

I can't believe there are adults that learned something new from that lol I love all your videos don't get me wrong.

[@UvThe1st]

Great video! Those bubbles under the eyes, nose, lips etc., you said a pressure pot wouldn't quite get rid of them so how about a vacuum chamber? I've seen videos explaining the 2 before but I'd love to see you explain a little more about them :)

[@RobertTolone]

There are so many challenges with vacuum casting resin that I gave up trying years ago. It’s so much simpler to orient and vent the model properly in the mold. You can get perfect castings almost every time just doing that. Occasionally you may have to tilt or rock a mold or even pre-fill areas of it with resin. But usually good venting does the trick.

[@Mi.wagh786]

It is very very helpful. You should teach us in our college.

[@RobertTolone]

I taught at Art Center College Of Design years ago. On KZbin I can reach a much bigger audience but I miss the live interaction with students.

[@dovel1000]

This was very helpful!

[@RobertTolone]

Christian Dovel Good to know! Thanks for reaching out.

[@Jerry-67]

Hey there.. Awesome content.. Very informative. I wanted to ask what brand silicone do you use? Thank you in advance

[@RobertTolone]

I use Econosil-25 from www.silpak.com.

[@Jerry-67]

@@RobertTolone thank you sir

[@markhenning2813]

How helpful is it to have a method of vibrating your mold when casting to help remove bubbles while pouring?

[@RobertTolone]

I never got vibration to work for me. So I gave up on it. With proper vent placement it’s not necessary anyway.

[@brucekiefer2209]

Great job!

[@RobertTolone]

Thanks Bruce!

[@edwardmurray2284]

Also, I really want to cast larger stuff to use fine art in the near future. I want to do it economically. Maybe slushcast or rotocast back filled with expanding hardfoam. Not sure if you do that stuff, I've only seen videos for the most part regarding these processes. Do you cast using any materials other than resin?

[@RobertTolone]

Foam backfilling of rotocast pieces can work really well. I’ll do videos on it as those projects come along. Also, RIM molding, which is reaction injection molding. By the way, here is a perfect example of when even industry substitutes the word molding where they mean casting. RIM is injecting self-skinning foam into a mold that is able to withstand the pressure of expansion. The foam expands to fill the mold and also creates a hard shell at the same time. Because of the difficulties of creating the mold I have only seen it used in industrial manufacturing. But I have experimented with it a little.

[@edwardmurray2284]

@@RobertTolone Awesome, I will look into that. I tried using expanding foam on a platinum silicone mold before, but it didnt really skin. Any number of things I could have done wrong... I saw that you had more videos than I was able to access before. Not sure why Im having trouble navigating it, but for example, Im seeing a part 4 or part 5 of one of your videos, but cant really find the first one to watch sequentially. Perhaps if you made playlists on your homepage thing for organization?

[@edwardmurray2284]

Nvm, I think its just me. I didnt spend enough time trying to navigate. Seems like its there already.

[@nandingpanelo]

Nice

[@sonnybie6194]

really helpful!

[@RobertTolone]

Sonny Bie glad to hear it Sonny, thanks!

[@Greyboa45]

You nailed it!

[@RobertTolone]

Matthew Aysse Thanks Matthew!

[@verdantpulse5185]

I wouldn't limit molds to being filled with liquids. Carbide machining cutters are pressed in molds, compacted from powder and subsequently sintered; sand molds for metal casting are compacted from loose sand. Capable of being filled with a flowable material seems a better way of saying it. Concrete is an aggregate mixture to my way of thinking, not a liquid; but with propper technique it can be molded.

[@RobertTolone]

There are many worlds in the universe of molding and casting.

[@verdantpulse5185]

@@RobertTolone Indeed!

[@amilcarmiguel7274]

Obrigado pelas ótimas dicas . 🇧🇷Londrina, Brasil.

[@RobertTolone]

De nada!

[@emmerge]

Not elementary at all! - loved the drawing explanation of vents / sprues and avoiding air bubbles. :D

[@RobertTolone]

Glad it was helpful! Thanks so much for your comments.

[@08diegobc]

Helpful, thx

[@MsZzzipper]

I’m trying to learn how to take a live flower and create a mold. Any suggestions?

[@RobertTolone]

Silicone rubber can reproduce detail down to the microscopic level. But it has a bad habit of sticking to porous surfaces. So it can bond tightly to wood, paper, cloth etc. So your biggest challenge will be preventing the rubber from bonding to the flower parts. What kind of flower are you trying to reproduce?

[@MsZzzipper]

@@RobertTolone thank you for replying! I’m trying to reproduce a daffodil.

[@RobertTolone]

@@MsZzzipper Extremely difficult but not impossible. You will almost certainly have to break it into lots of separate pieces, cast them and assemble the finished flower.

[@MsZzzipper]

@@RobertTolone ok, thank you. I might make it an ongoing project. Lol I don’t think I’m that skilled!

[@M4rt1nX]

Thanks a lot!!

[@RobertTolone]

Thanks for watching and commenting!

[@Stivaartist]

You are the best

[@RobertTolone]

Thanks!

[@onkarpatil140]

Yes it is helpful thank you

[@RobertTolone]

I’m glad it was useful for you. Thanks for watching.

[@onkarpatil140]

@@RobertTolone sir your content is so awesome and realistic. I am from India, you should target indian audience, as we have good population, you will get popular easily here, if you post more practical videos. I mean this was the first video of yours which i saw.. anyway see if you can do something about it.just beacuse you deserve it

[@RobertTolone]

@@onkarpatil140 Yes, I should begin to have my videos translated into other languages. I have been waiting to see if my channel would be successful enough to make it worth the effort. I know that many languages are spoken in India. Do you think the best language for me to use there is Hindi?

[@onkarpatil140]

@@RobertTolone yes hindi will attract most number veiws, but it would cost you much to translate, i suggest you first make a audience base here, with English also you can do it, you can see the engineering degree courses and start making videos related to it, that will really help you, or have a look on other indian content creators are doing, But still yes hindi is the national language and by that you can attract many people, but i would suggest to have your channel settle here first and then go for dubbing. I hope you get my point. Please do go through the courses offered in indian mechanial engineering

[@tylerevans2261]

Fantastic. Do you have a business. My company is looking to create low volume/low-cost injection molded prototypes using our resin.

[@RobertTolone]

Contact me at [e-mail].

[@ivelsoup]

So a mold makes a casting?

[@android01978]

The real question... is it molding or moulding? 😂