Crazy Cuts Can Create Clean Castings

Even a small object can require a complex cut pattern in the silicone rubber mold.
One of the biggest advantages to one-piece silicone rubber cut molds is that you can create a very complex cut pattern that hides the parting lines on the object and results in a very clean casting.
In this video I demonstrate how to cut crisscross parting planes that hide the parting lines on the inside of a ring; resulting in a very clean casting requiring minimal clean up.
Thanks to Michael for printing the skull ring for us.
He has an excellent channel on 3d printing called Nerdtronic.
Check it out at: / @nerdtronic
TIME STAMPS
00.00 Skull ring STL file sent in by viewer Osman.
00.23 How the ring was printed by Michael at Nerdtronic.
02:53 Testing the ring resin for cure inhibition of the silicone rubber.
03:27 Mounting the funnel, sprue and vents on the model.
04:13 I bought a assortment of wax rods of different shapes.
06:02 Mounting the ring in the mold cup.
06:35 Pouring the mold rubber.
07:56 Cutting open the mold.
17:25 Mixing and pouring the resin.
19:20 Putting the mold in the pressure pot to cure.
20:08 Opening the mold.
20:42 Inspecting the casting.
21:10 Cutting off the sprue and vents.
23:50 Save the cut off funnels for use in future projects.
24:04 Use a Dremel tool to cut the sprue off down inside the casting.
24:44 I hope you enjoyed the video and hit that like button!
Here is a list of suppliers for the rubber, resins and waxes I use in my videos: www.dropbox.com/s/kz6mhmf7v5v...
Do you have a project to suggest for the channel? Here’s a .pdf with everything you need to know: www.dropbox.com/s/pjb0l6fr7zj...

[@BaronMcCausland]

"The Mysterious Weird Things"; and, "Mold Pollution"; both are good names for a rock band. By the way, the yellow-colored resin is fantastic!

[@m.b.boyack2228]

Attention Alliteration Addicts Another Robert Audio-video Attraction Awaits. Great casting of a relatively difficult shape. Not filling in the 'zygomatic arch' (hole in cheek bone) makes great detail, even though filling this area would have made for easier mold making and removal, although compromising a loss in realism. Cheers.

[@RobertTolone]

Alliteration and zygomatic in the same comment. I have the smartest viewers!

[@bikerfirefarter7280]

Attention ALL AVID Alliteration Addicts Another AWESOME Robert ADEPTLY ASSEMBLED Audio-video Attraction Awaits AUDIENCE APPRECIATION . I'll stop now. ;-)

[@SeonasStudio]

This channel is why the internet needs to continue to exist! 😊 excellent video thank you. I’m trying to work out how to cast some rings and this taught me a lot!

[@txikitofandango]

The casting looks even better than the print, amazing

[@BrianMillerCEO]

Have to admit I was expecting it to fail with those tiny cheek bones. Bravo!

[@terryperrott8567]

I've learned so much from watching your videos, & you do a great job. Thank You for sharing.

[@annekabrimhall1059]

This is definitely something that you haven’t done before. You’re very good at keeping it new and fresh.

[@RobertTolone]

It's because the viewers send in all kinds of crazy things like realistic baby heads. ♥😊

[@ronjlwhite8058]

the sprue & vent pieces are nice extra tools. sweet job on the castings.

[@stefanfrisk9598]

I was glued to the screen thinking about those holes - "He's not gonna get it out" :) Nice one!

[@chrisnunez4758]

Amazing getting all that detail from a small ring!

[@Acheiropoietos]

Really tricky looking method but you proved it was possible.

[@holzmann8443]

A sticky lint roller with disposable tear-off sheets can help with resin confetti on your clothing, or evil things like glitter. Amazing work on that skull ring! Very clean castings. I'm partial to the yellow one since it shows up so well on camera.

[@RobertTolone]

Never thought of using a lint roller. Great idea!

[@timosteen]

Good to see you back! Have you considered having the pour funnel and vents modeled and printed as well? The idea being that the ring would be printed with them already attached in the right place, and all you’d have to do is attach the whole lot to the bottom of the mold box and pour

[@RobertTolone]

Yes, I will eventually do a project where I receive an STL model and add the vents, sprue and funnel before I print the file. So many possibilities using 3D printing!

[@ComicClub01]

@@RobertTolone Just think about it, the airvents wont brake of as easy as with wax. Neither the funnel.

[@drewgossage8842]

So small, yet sooo clean! Great job!

[@UnicronsLeftNut]

Welcome back, Robert!

[@bricegordon64]

Good to see you back!!

[@glenfisher728]

Good to see you back Bob. Hope all has gone as well as can be. Always love those complex cut moulds , you have a good way of showing and explaining what is going on . And always vent your moulds ! Take care mate

[@yugos.oficial]

amazing work!

[@fordeetv]

Another great video Robert! Cheers!

[@osmanaker2927]

That was great and really interesting to watch Robert ! Thank you for doing the project, I have learned a lot and I'm actually pleased that you enjoyed the project and was a little bit of challenge for you. Keep it going, you are great !!

[@jezfish1]

Welcome back Robert. Another great video well done. Best Regards Jez

[@RobertTolone]

Thanks Jez.

[@tftf60]

Good to have you back.

[@JoaoRodrigues-cb9zh]

Great video as usual. Super cool stuff.

[@SoloRenegade]

Really love watching your videos, I always learn something and your videos are so relaxing.

[@ChempZee]

Wicked cut. Nice job

[@ProcessLoveCandy]

Loved it. thanks!

[@classicmetaldude]

You make everything so easy to visualize, I appreciate your work so much!

[@GaryMcKinnonUFO]

Thanks again i'm loving your videos :)

[@roger.agburn]

Bridges really are something. I sometimes don't see them directly in my model and then get into problems cutting the mold. I guess that's all just about experience and not missing those spots when inspecting the model. Nice video!

[@darrensmith4606]

Great to see you again Robert

[@RobertTolone]

I appreciate Darren!

[@aaronsotofernandez5]

Awesome!

[@HaikalArts]

nice work thank you

[@gabrielaalcantara9984]

Good to see you back! What a great modeling on that piece. I couldn't have started to imagine how to make that mold.

[@RobertTolone]

Thanks Gabriela. It could have been much simpler, but then the cleanup of the castings would have then much more work.

[@J0nnyTheJ3w]

Great stuff Robert, glad to see you back!

[@RobertTolone]

Hey, thanks!

[@matthewdowning7069]

Great project! Your channel has helped me with my molding and casting so much. Thank you and my condolences.

[@RobertTolone]

I’m glad you find my videos to be helpful Matthew. Thanks for watching!

[@coffeybean04]

Glad to see you back in the saddle. Great video. Those are some interesting cuts.

[@RobertTolone]

Thanks Anthony!

[@markhills3922]

Yet another perfect cast from a very difficult piece. Good to have you back Robert.

[@RobertTolone]

Thank you Mark. That was a fun one to do.

[@securityrobot]

Good to see you back, and thanks for this video that has mould making and casting all in one. Mind you that’s quite a complicated cut job so count me in for another viewing.

[@RobertTolone]

I wish that all my projects were completed in one video. But the viewers always say they want me too show as much of the process as possible. So only simple projects like this one can be compressed into one week. I just can't make videos much longer than 30 minutes in one week.

[@brandonrobinson1603]

You're my new favorite channel

[@classicmetaldude]

POUR FUNNELS! SO COOL! I shall make my own as well!

[@treblam1]

Cool!!

[@Nos4a2a]

Fantastic!!

[@RobertTolone]

Thanks!

[@davidhoogewijs1718]

i have to say it Mr Tolone,yet another great video,always exiting to see where you will make the cuts :-)

[@RobertTolone]

Thanks David.

[@jasonrobinson252]

Great work!

[@RobertTolone]

Thanks!

[@szymonm.8138]

Awsome job Robert ! always love to watch you at work :)

[@RobertTolone]

Thanks for watching!

[@vernonleeper]

As always an excellent video.

[@RobertTolone]

Thanks Vernon!

[@Professorvapes]

lovely video thankyou

[@RobertTolone]

So nice of you, thanks!

[@levinebette15]

Great video Robert!

[@RobertTolone]

Thanks Bette!

[@faultyinterface]

Oh, I love Nerdtronic, always happy to see when youtubers I watch are friends

[@RobertTolone]

Michael is a great guy as well as super talented.

[@Krenshondizerkhan]

Welcome back ❤️

[@ArcticFlies56]

Bob, another enjoyable video. The rings you displayed, one on each finger is definitely you! Very stylish. Best regards, Richard

[@RobertTolone]

Skull rings - definitely my style! 😀

[@fuqorock]

Nice

[@debrajol3585]

Awesomeness & such a tiny little project! I totally enjoyed this . I’ll definitely go check out your friends 3D printing 👌 Robert your channel is such a pleasure, I hit the LIKE on my way in. Glad to see you back. Warmest regards about your father.

[@RobertTolone]

Thanks for your kind words. Much appreciated.

[@henrexfiberglassproduction7794]

Amazing

[@RobertTolone]

Thanks!

[@grimmace2131]

Triumphant!

[@amonynous9041]

that's really cool, if you could cast silver I'd be interested in having one of these

[@Yunchanghun]

Good

[@stevemyers4552]

Welcome back. Hope everything went well. Keeping good thoughts for you.

[@RobertTolone]

Things are good. Thanks Steve.

[@flytrapjohn]

Wonderful stuff. This above all, has shown the benefit of cut molds. How may rings do you estimate you can pull from this one before it becomes too damaged? Thank you everso, Mr Robert.😊

[@RobertTolone]

Minimum 10, possibly 20 with urethane resin. With other materials you could potentially get a lot more.

[@shaunavconnelly9022]

Love this project! Dremel use a nice addition (love the use of everyday tools.) Which Dremel bit was that?

[@RobertTolone]

Bit # 134. I don't own a dremel; in my home shop I use a pneumatic grinder. But here I was able to borrow one from a kind and sympathetic friend.

[@noviceartisan]

That blasted ring is the very first thing I tried to learn to makign moulds with haha I must have tried 4 different times, and even then I couldnt' get a consistent clear cast in wax from it, as it either broke during removal, or didn't fill fully etc. Love how well you've done this, wish i'd discovered your channel when I first started getting into this a few years ago, would have saved me SO much silicone haha ^_^

[@RobertTolone]

I’m trying to build the channel I needed when I started mold making in the 80’s! I wasted a LOT of rubber and resin in those bad old days. 😄

[@noviceartisan]

It's really appreciated what you're doing here man, your contributions are so very helpful! I'm already recommending your channel as the goto one for anybody I see that's just getting started, there's no comparison to your wisdom and skill in this field, and I've watched a LOT of videos on the tube 😂. So very happy that you're freely sharing this with us all!

[@Mehmet-ie1zv]

Best youtuber ever

[@RobertTolone]

Thanks!

[@wollibar5263]

Great to have you back on fridays. One thing I never understood is why don´t you use glass or metal marbles(?) inside your resin containers to aid shaking up the B-side ? Great video once again. Castings are looking top class - will you perhaps polish them as well?

[@RobertTolone]

I never thought to add them and just plain old shaking seems to work fine. These skulls would buff up really nice! Too bad my polishing equipment is in my home shop. 😢 No worries, we'll do some polishing in future videos.

[@sikokkh4891]

good! I'm looking for your Amazing ring

[@TheZahnputz]

as far as i experienced inhibition only occurs with platinum cure silicones. what are you working with? when it has to be platinum sillicone the resin then needs to be thoroughly cured (preferrably in a water bath) and coated as thickly as possible (one coat of spray paint may not work). Additionally, a rubber with high reactivity (fast and hard) seems to work better since the incompatible chemicals dont get a chance to mix

[@RobertTolone]

That’s why I rarely use platinum rubber. But I’ve had some tin rubber cure inhibition problems over the years.

[@SoloRenegade]

Everyone is all caught up in 3D printing these days. But after finding your channel, I've been working on starting resin casting now, as not everything needs to be 3D printed. Many things I'm doing I would prefer to do in a single piece without layer lines, be able to make multiples faster and with better resolution, etc. 3D printing has its advantages, and some things can only be made through 3D printing, but I like having options, and sometimes 3D printing just doesn't cut it for me.

[@RobertTolone]

I have done both hand sculpting with wax and 3-D printing during my career as a toy prototype sculptor. 3-D printing has made extraordinary progress in the last 20 years. But often, good old hand sculpting, molding and resin casting is faster and better.

[@dwdidit3664]

I'd love to know more about the cutting of the rubber moulds. One thing comes to mind, and it's that, to try to pull a wax model from that mould would be problematic. Am I wrong? New subscriber here by the way, and I bow to your superior knowledge.

[@RobertTolone]

I always expect that a model may be damaged in the molding process; especially soft models made from wax and clay. For me, the casting is the important thing. The model is just a step in the process.

[@yoopermann7942]

what kind of scale is that? and where can i order one,, thank you for the tips

[@RobertTolone]

It is an Ohaus triple beam balance scale. Mine reads to 610 g but I would recommend you get the ones that read to 2610 g. That makes it much more versatile. Be sure you get one with the tare slide. I built tare slides for my scales and I don’t understand why Ohaus sells as an accessory because it is absolutely crucial you have a tare slide on your scale. They allow you to set the scale to zero when using a variety of different size containers. These scales are available from lots of places on the Internet. Current cost around $160. Other brands are cheaper.

[@DonTheVeteran]

Love the video. I do have a question. What is the differences between: Sticky Wax Sculpting Wax Blue Stick Wax When do you use which? Maybe this could be a nice instruction video, too.

[@RobertTolone]

I use all three waxes in almost every video. So you can watch me use all three in many different use cases. But the short answer is the sticky wax is used as an adhesive, the blue stick wax are used mostly for vents and the brown wax is used for sculpting and filling in gaps.

[@LABrynthStudioLeonABain]

I have a mimic dice box I would like to make a mold for. You had said in one of you other vids that I may send something to you to demonstrate how to mold it. Is that still a thing?

[@RobertTolone]

All my video projects are sent in by viewers. Send pics to me at [e-mail]

[@TKTrooper]

where can i find the STL for this ring?

[@cesarmata9062]

what are the pros and cons of doing this project manually? (How do you do it) and what are the pros and cons of using a plastic injection machine?

[@RobertTolone]

Doing it manually has a very low start up cost and is very flexible in that it can make a large variety of castings. The cost per unit is high because the labor is so expensive. Injection molding requires a much larger initial investment but it can produce a lot of finished products quickly and cheaply.

[@betogaona3d.]

Dear Sr Robert, may I ask how much PSI pessure do you use on your pods ?......is it always the same pressure?

[@RobertTolone]

For most things I run them at 50 psi. Occasionally I will crank them up to 80 psi but I find that it usually isn’t necessary.

[@runin1wild]

Fine details , good video! Foreign Object of wood? Maybe from your stir stick. 🤷🏼‍♀️

[@RobertTolone]

There’s a lot of wood dust in my shop. But the stick could be the culprit. It’s extremely rare for me to get debris in my molds.

[@masswired7431]

Hello, i have a few questions regarding resins. I am a CNC machinist and recently started experimenting with resin projects. Ive been CNC cutting my molds into HDPE plastic to make necklace charms. I dont particularly like the weight of my final product. - Do some resins weigh more than others? -What would u recommend to add some weight? (I cant make the thickness of the mold larger due to the limited cut length of a 1/16 bit..) -How about durability? Im using “alumilite deep pour” is there something better you recommend? -Do you take custom orders? Could i contact you privately for a silicon tray of 50-100 small logos nested onto it? (Also lighter cases, grinders, a small 2 part box like in your video?) -Is there a proper ratio for pigment powder or do everybody just eyeball it? Ive had some powders that stay throughout the whole part and others that just settle to the bottom of the resin... why is that? How can i prevent it so the color stays fluent through out the entire part?

[@WhenDoesTheVideoActuallyStart]

Look up cold casting, and fillers. You can cast resins filled with metal or stones, but typically you will lose tensile strength. Not worth it. End the cult of heavy.

[@per_sev]

Is that a new scale there, or did you just super clean your old one? Also, was the nut, and washer on the scale to be above the minimum weight of the scale? That mould looks crazy to cut. What a super cool project.

[@RobertTolone]

New scale. I am in a temporary shop set up in a friends garage. The other 30-year-old beauty is in my home shop. The nuts, etc help to balance the scale with different size containers.

[@per_sev]

@@RobertTolone nice.

[@ualdayan]

Have you ever casted with expanding urethane foam? My attempts to make a sign using it always resulted in big air bubbles.

[@RobertTolone]

Foam casting is a whole other thing. Most methods involve designing molds so that when the foam expands it pushes outward toward vents in the mold which releases the air. In reaction injection molding, the mold is held in a very strong case so that when the resin expands it pushes the air out of the vents but also is self skinning So it forms a rigid shell. I have poured urethane foam into rotational molded pieces to make them stronger. But it is always difficult to fill the mold completely without bubbles.

[@ArindursForge]

Hey is this STL available for me to have printed? This looks like it could be fun to use to learn some investment casting. I've been poking about learning metal casting

[@RobertTolone]

Email me [e-mail]. I don't own the design but I can put you in touch with the guy who does and you can ask him if it's okay that you use it.

[@ArindursForge]

@@RobertTolone awesome I'll send an email, thanks!

[@HaileyCrys]

Have you ever tried using Gypsum powder instead of resin? It dries softer even though its a fine powder cement. Wondering how you would fix bubbles or small parts that break off when you de-mold etc. (I have this gorgeous frog mold that I keep breaking his fingers off pulling him out of the mold) I have things in my house I want to make a mold for and use the Gypsum powder and then paint. The powder costs about a dollar a pound from the manufacturer and mixes at a 2:1 ratio powder to water and takes 1 hour to cure.

[@HaileyCrys]

because its porous the only thing i have been able to find so far to re-attach fingers is gorilla wood glue... and then use my dremel to make it look like a finger again. Oh and for demolding and some bubbles spraying dawn dish soap and water seems to work most of the time... but not always.

[@Warghoul]

Great video! Are you selling those rings?

[@RobertTolone]

No, the design belongs to Osman who sent the project in. I don’t know if he is planning to make them for sale.

[@Warghoul]

@@RobertTolone ok thanks!

[@A.C.Walker]

I have a 2 inch skull. How do I make a proper bridge for the jaw, to make a silicone mold?

[@RobertTolone]

I’m not sure I know what you mean by a proper bridge. When I cast a skull the jaw is usually cast as a separate piece

[@A.C.Walker]

@@RobertTolone I see, thank you.

[@edwhal06]

Just like that

[@raggeysoap6188]

❤❤💯👌

[@stevevaughn2040]

Do you like this 3D printer mold making better than the wax rings? I have never seen a 3D printer

[@RobertTolone]

3d printing and wax sculpting are pretty similar. except I would only use 3-D printing for highly mechanical parts, like machines are robots, etc.

[@cesarmata9062]

is it possible to do it on a INJECTION MOLD MACHINE?

[@RobertTolone]

It would depend on the material that is being injection molded. If it was a hard plastic or metal it would not be possible because this ring was not designed for injection molding. There are many undercuts and areas where the plastic would lock into the rigid injection mold. That is why the design of this ring required casting in flexible rubber tooling.

[@noneckjoe948]

Hi Robert, how do I hire you for a project? (Discontinued RC car body parts molds).... I’ve tried unsuccessfully and at my wits end on replication...

[@RobertTolone]

send pics to me at [e-mail]

[@A.C.Walker]

Excuse me again, I was wondering how do you deal with tiny details like loops, tiny coffee mugs for action figures?

[@RobertTolone]

The rubber forms a bridge that goes through the loop of the handle. You simply make a parting line through the handle by stretching the rubber on one side of handle and cutting across the rubber bridge.

[@fredswanson6089]

I was just wondering why not poke a hole in the bottom of another cup. Put the mold in it and turn it upside down to pour resin. I would think the pressure around the mold would be just right.

[@RobertTolone]

It’s a good idea in theory. But in practice cups - even those from the same package - are not identical. So the new cup may or may not close the mold accurately. Plus with rubber bands you have very good control over how and where you apply pressure.

[@jakesells2379]

Maybe the chunkies were fragments of a stir stick?

[@RobertTolone]

Very possible. There's a constant battle with wood debris from the tools in my shop.

[@KyleTO7]

I thought your supposed to cut molds with a sigzag pattern so it all interlocks together?

[@RobertTolone]

I do cut interlocking planes. But most people make much too ragged a cut which is not only unnecessary, it is counterproductive. I think of cutting planes like making a 3D topographic map instead of a sawtooth zig-zag pattern.

[@DKarkarov]

I wonder what the time frame was from him printing the skull, to you getting it, to you doing the test. Typically it takes a week+ (a month to be safe) for this type of resin not to have cure inhibition issues..... unless of course that was tin cure silicon.

[@EvileDik]

Th UV resin used in the resin printers needs to be cured fully under strong UV after printing and IPA wash (as you may know). One isssue that the UV resin has is its surface stays tacky as oxygen inhibits UV resin curing, I've found by doing the cure under water this effect can be negated, and my prints are directly usable as masters same day with RTV silicone.

[@DKarkarov]

@@EvileDik The only thing that is guaranteed to work is A: use tin cure silicon, and B: give the resin an extended time before use in mold making. Well or C: use a very high end industrial grade printer that uses a completely different kind of resin that has no inhibition issues. Like a formlabs. I did check out Roberts part list he links in this video description and sure enough, he uses tin cure silicon. So in this case it was a non issue.

[@RobertTolone]

Michael from Nerdtronic (who printed the skull for me) told me that this resin definitely causes cure inhibition in platinum rubber. I almost always use tin-based rubbers.

[@EvileDik]

@@DKarkarov Yeah all mine seem to be tin RTV apart form one batch that I specifically got as food safe. UV resin comes in 2 forms, Acrilate (radical, cheap and weak) and epoxy (cationic, expensive,strong, this is the stuff they make dental work from). 3d Resin printers can use either as 405nm curing wavelenth is universal, it just matters how much you want to spend on your resin. You can tell in the finished product which one you have, Acrilate is usually milky with a lot of sub-surface scattering and super brittle. Epoxy is pretty much unbreakable by hand over a 4-5 mm thick.

[@AutismusPrime69]

Why cast replica of 3d printed ring in more resin?

[@RobertTolone]

Printing vs casting, which is better? both have their advantages and disadvantages. Some casting advantages include a wider range of casting materials, speed of production, lower labor. But really it depends on what it is you’re making and what your resources are. Ultimately, I think printing will become the dominant method of production.

[@cesarmata9062]

is it possible to make a living from this job? I don't mean what you do. I mean creating silicone baking molds and selling them. or is there some more automatic way, for example with a machine.

[@RobertTolone]

Anything is possible if you design your business correctly for a good market. Mold making runs from the kind of custom prototype work I do all the way up to highly automated machine processes. Your level of automation will depend on the volume of product you sell.

[@ArindursForge]

When you've got a standard sized repeatable mold case like a cup, why don't you make a securing ring out of another instead of using rubber bands?

[@RobertTolone]

Because weirdly, cups are not identical. So the cup that molded the rubber will be a slightly different size and shape than the new cup that you are trying to hold the rubber together with. Also, you cannot see the parting lines. With rubber bands you have a clear view of the parting lines and you can make sure that they are closing properly. In a cup you cannot do that.

[@ArindursForge]

I hadn't thought that the production variance would matter but that makes great sense, thanks for the reply!

[@levinebette15]

My fingers hurt watching your fingers tremble!

[@RobertTolone]

It's not that I'm old or feeble, I just do that for added drama.

[@deweyrayfield6701]

cct

[@TommyWashow]

now THOSE are mans hands. dont make em like they used to eh

[@paulhayton3423]

Trust me, it's going to take a lot to ruin your reputation.

[@RobertTolone]

Haha Paul, only on KZbin. In the real world it disintegrated decades ago!

[@josephstevens2123]

Hey young man don't cut yourself

[@RobertTolone]

Been running a tablesaw for 40 years. Still have all 10 fingers! Knock on wood.

[@thevvizard823]

Amazing

[@RobertTolone]

Thanks VWizard!