You need to incorporate small vent holes to release the gasses as they form. Small thin wires will do the trick. Just poke them in near the top as the plaster / investment hardens. Then pull them out when the investment sets. It will leave small extrusions but they are easy to remove with a dremel or other cutting tool. Also, add some vermiculite to the plaster to help control cracking.

Hey Grant, To get better results when casting aluminum you've got a few options. Being what you're doing here is investment casting, you could go further down that route with a more complicated colloidal silica slurry & refractory sand or flour set up that requires firing the ceramic shell, etc. But if you want to keep things simple, you could go with something like Green Sand, which is just a coarse or fine grit of sand (like sand paper) mixed with bentonite clay (may be available at local health-food stores as bentonite powder, for abdominal problems) and water, made specifically for metal casting. As a bonus is, it's even reusable several thousand times, and if it dries out just add a little water, and stir. The only parts you would need to replace over time, are the wooden mold boxes, called a "cope" and a "drag," that are combined to make up the "flask."It's porous so the steam has places to escape, unlike in molten aluminum/cement explosions. And if that still won't work for you, I've heard of people using super fine colored play-box sand! Hope this helps! Matt, aka: The Cosplay Supply Store

Miss you man I have a part in my life missing without you

Rip you were a total legend dude you will be missed

To avoid the air bubbles (they come from gases in the molten metal specially from hydrogen) you could use: 1. a vacuum chamber after the cast 2. postheating the mold specially the sink heat If you want to improve the quality of your mold furthermore give investment casting a try. One tip: To remove impurities use flux and then get rid of the dross by skimming it. I really appreciate your show =)

Hi Grant! I've been studying iron casting at school, and have a suggestion that may help reduce air bubbles. When we cast, most often we use bonded sand, and we always drill out TWO holes, one for the sprue and one for a vent. Adding an extra vent means more we have to cut more off the final casting, but it also allows gasses to escape from a different hole than the one you're pouring into. It should work the same on plaster as well! Thanks for the awesome videos!

May he and his projects rest in peace

“We are going to salvage as much as we can” *Proceeds to pour half of the aluminum on the ground*

"It says to heat it up and cool it down a few times so it doesn't crack but I'm not patient enough for that" "It cracked in half! That's $40 down the drain" REALLY

This guy needs a diamond play button...NOW

Make a plaster mold, pour silicone in it and BOOM. You now have uour own bouncy (Poké) ball

Rest in Piece Nate. We will forever love your experiments. Not just that, but your amazing personality

AN ADVICE: Greg, I am a great fan of what you do. I have learned a lot of things from you. I am a PhD student working on metal casting. So, i have some advice for you when you try to cast metal: 1. Always preheat the metal as much as you can. 2. Preheat the mold as well. This will prevent undercooling, and hence porosity in the casting. 3. If you are making wax casting, you don't have to melt out the wax. Pour the metal directly in the mold with the wax structure in it. The wax will instantly vaporize and moreover, will give you a better surface finish. 4. Speaking of surface finish, try Lost-foam casting (using styrofoam) since you already have a cool styrofoam cutter, this will be easy for you. 5. When you pour molten metal into a cavity, make sure you are pouring the metal at a constant rate forming a continuous stream. This will prevent air bubbles entrapment. 6. Add a riser to the mold design, this will take care of the solidification shrinkage of the metal. Hope these tips help you. Regards, Your BIG FAN!

Try putting the moulds on a vibrating surface as you poor them and as they set. This will help get the air bubbles out. I used to make concrete garden gnomes and we always poured the cement into the moulds on a vibrating table to help get the air bubbles out.

If you add holes in the top that lead to the casting chamber and don't pour aluminium in them then the gasses can escape and the pressure doesn't rise inside too much

this is truly what tkor is about, so much better than the new vids

Ok so I have an idea. first do a mold of your face. And then do an aluminum pour of that.

You should put your silicon molds in a vacuum chamber before letting them fully cure and set. It'll force all the air bubbles out, due to the drop in air pressure.

Casting with liquid metals is so satisfying for me

I can finally make the Steel Balls I've always wanted...

Probably the most i've seen you struggle in a video before and you handled it like a champ!!!

How to be a nerd: use a master sword to make a pokeball.

They really look like the thermal detonators from star wars

I love how the second plaster mold breaks on the beat drop. so satisfying tbh

Can you cast me a bright future?

Hi Grant, I enjoy your videos a lot. I have some small pieces of advice. 1. Mix some sand into your plaster. This is how you make what is called an investment, which i'm sure you'll agree is an apt name. A ratio of 3 to 1 plaster to sand is about right. 2. Make a thin coat of just plaster and sort of splash it onto the surface of your model. This provides a very clean surface, and prevents sand and air bubbles from marring the surface of the cast. 3. Most important tidbit! When you are lost wax casting, it's very useful to use a sprue system. A sprue system is made by connecting max to the top and bottom of your mold, one an exit from the top, and the other connection leading from the bottom of the piece, to the same level as the exit. I use a paper cup affixed with glue or wax. When it's all put together, you should have a U shaped apparatus. One leg of the U has a large diameter cup where you can pour easily, and the other is a smaller vent hole. When pouring, you pour until the aluminum comes out the vent hole. The usefulness of the sprue system is two fold, as it allows gas to escape, instead of having to exit through the liquid aluminum. It also creates a reservoir of liquid aluminum, which the mass of the model can draw from, assuring that it entirely fills the space. 4. One last thing, I swear. To properly burnout your investment, you need to bring it to 2 distinct temperatures. Both should be approached slowly. First step is as you showed, melt out wax at a low temp. Next you should bring the investment up slowly, something like 250 degrees an hour, to 700 degrees Fahrenheit. Hold it there for a couple hours. This ensures that all carbon is completely removed from the model. This is probably where your gas is coming from, small bits of wax trapped in the surface of the mold. After it has stopped smoking, or you've hit 3 hours at 700, bring it up even further to around 1300 degrees. This removes all chemical moisture from the investment, which is being held by the plaster molecules. Your current curing temp is enough to remove mechanical moisture, or water that is being absorbed by the plaster matrix. But when you drop a 1300~ mass of liquid aluminum in there, it immediately starts removing the chemical moisture in the plaster, which can, among other things, crack your mold and off gas into the piece. I'm not sure if you'll actually read this, but it just so happened you entered into a realm of my expertise. Happy experimenting, and keep the great hobby videos going!

R.I.P thank you for your time and idea’s

Rip you were One of youtubes best youtuber

you should sand it, polish it and paint them like the real deal

Cast my dad so I can see him for once

😭😭😭😭😭 every time it hit so hard without the legend here

I laughed so hard at the beginning, I make random things into plant pots too, like the rim of a car tire and a bobsled and forgetting what you did with something like that is so something I would do 😂

you need an exhaust port for the mold, you can't just have a single pour port the heated gases need a place to escape

6:20 The pokeball looks so cool here! It's like some ancient relic that an archaeologist dug up. Personally, I really like how they looked before you cleaned them.

As a student metal-caster I can offer the following advice: use a product called Hydrocal instead of plaster of Paris. It's more like cement, it's tougher and can also withstand heat better. Also vent holes are your friend, they can help remove air that gets trapped in the molds and prevent cracking.

this series was so satisfying

he's got balls of steel

Make your logo in iron or jello

im a goldsmith and im impressed that you get this process by yourself. we goldsmith used a similar technic for jewerly.. exept that im the final step when you pour the melted metal you need a centrifuge or a succion machine to make metal go down and get better results with less imperfection on surface and less air bubbles inside the jewel

Love how we learn and experiemnt with him in the comfort of our own home.

For the next silicone mold you make why not paint a layer of silicone on to the object first let that cure then do the filler around that to add support to the fine layer around the object? This would give you control of what touches the object and you have already seen silicone will bond to silicone so it should keep its strength after. Doing it in 2 steps would also let you introduce reinforcements between the layers in ether solid or fiber form.

"we have to salvage as much as we can" pours it all on the ground.

It's amazing how from silicone to wax to metal!Awesome work!

Hey Grant, you should try casting the "The King of Random Logo"

make an aluminum chicken and put it on a plack like a trophy. I think it would be funny and random as heck to see a chicken trophy sitting next to someones real trophies.

Hey random person going through the comments I hope you have a great day and a merry Christmas ;)

well you just took this whole experiment from 0 - 1000 real quick.. great content brother.

The first one already looked like a quick ball with messed-up paint when it came out. Rest in peace. You were the best thing to happen to KZfaq.

honestly, those pokiballs looked better than the originals

cast your whole body into aluminium. and make a statue

Just a tip when using silicone you can stick the mixture in a vacuum chamber to help get the air out then pour it in a thin stream from up high so the rest of the air bubbles pop. That way you don’t get the air holes in the mold.

You are so awesome!! I wish that I could come over your place and make my own working pokeballs with you!!

maybe you can make solid metal legos, lol.

Cast a King of Random logo

watching the master sword melt broke me internally

today I learned: heat the crucible and let it cool before casting ;) Thanks for breaking yours so I don't have too! Also to avoid air bubbles, take a few bamboo skewers and stick them through the top spaced evenly to create vents in the mould. (coat them with vaseline so you can pull them out before you bake.)

PLEASE CAST A GUITAR!!!!! I'D LOVE THAT SO MUCH!!!

Try making Poke-ball with Proto putty I wanna see how high it can bounce.

Awesome! Like the music XD.

Hi Grant, I love all your video's and wanna thank you that because of you I have learned a lot. I have seen all the aluminum casting videos but what I really want to ask you if you can make a video of how to anodized it. Cause anodizing makes them stronger & if you can make a video of that I would really appreciate it. Thanks in advance ;-)

when this guy dies cast his body 😂

silicone cast one of your kids

Casting ideas: 1. Bowling pins 2. Glass bottles 3. Car parts (if you think you could use them as a substitute. 4. Something to put on the end of a wooden pole (rake, shovel, etc). It'd be cool to see something to remind us of "Age of Empires" or Civilization games. Progression through the metal tools/weapons, etc. 5. Suit of armor! 6. Shield 7. Props/toys from movies. 8. Various stands/mounts for cameras/lights/etc. 9. A whole arrow or crossbow bolt. 10. A bobblehead/action figure. 11. Other martial art weapons (sai, etc) 12. Sports balls (homemade trophy) 13. A large scale car or plane model. 14. A toy spider. 15. A chair! Even if you don't use these ideas, hopefully they give you some more of your own!

this is my first time watching and it's a great thing

Could you pour water in the mould then put it in the freezer? That would make a really cool ice pokeball!

Only Grant Thompson could lose a metal foundry.

Imagine throwing those poke balls at an animal trying to catch it tho...

still can't believe he's gone

You should make a marshmallow pokeball from the original mold

Your silicon mold was flawed from the pour, as it poured directly onto the blank the vicosity made it bend and fold over itself introducing air bubbles by the second, you need to pour slower in a corner of the mold that isn't occupied and let it fill that way. add fine sifted sand to your plaster to give it a little more durability, and it needs to be a denser mix all around, If you could vaccum it before you pour that would be awesome but it's not absolutely required. There should be enough sand to change the color of the plaster to something like light khaki pants, I eyeball mine based on detail i'm looking for and the temp I intend to pour at. Your shrinkage is a tough fix, add vent holes in the mold that meet the cavity about 2 mm below the first noticable defects. Failing that you might benefit from a riser as well, But I'd start with the vent holes, you can make them by rolling some parafin wax into a string and pressing it onto your wax ball before pouring the plaster investment, Paraffin wax is easily sourced and mouldable if you just get it from some fancy cheezes if you don't wanna buy some, It's actually easier to mold than candle wax in my opinion. and it'll melt out just as easily

Ceramic Slurry could be a solution for you. First you make your wax mold positive with a large sprew along with some straw shaped vent tubes. Then you dip the mold in the slurry [as per manufacture's instructions!!!]. Once it sets, the ceramic can be cooked with a torch to melt out the wax. And WA-LA! You dripped out the wax in a hurry and you have a slightly more expensive investment mold! Also, I absolutely love your channel. I am so happy you exist and are doing what you do! Keep up the random fun!

to help with the final cast of any kind of metal you should heat it up to where it's liquid like you already are doing but instead of slowly pouring it into the mold just quickly por it in so the metal as little to no time to harden back up which will give you better detail as well.

A suggestion: Maybe cast your glasses you wear? And wear them? Just an idea. :)

YOU FORGOT THE CHOCOLATE POKEBALL AND THE JELLO POKEBALL!

i want one!!! looks amazing :D

Tip for keeping the plaster from cracking: pour the plaster in an oven-friendly material such as a segment of steel tubing instead of the acrylic tubing and de-gas in the vacuum chamber before it sets. Leave the plaster in the containment material. Proceed as normal. To remove, drop the cast in a bucket of cold water while it's still hot. The thermal shock should break the plaster and free the aluminum. Learned in a nonferous metallurgy class.

i think he should paint them

1. Would you cast a metal controller? (X-Box, Playstation, ect.) 2. Is there a way to make a permanent mold, or at least more than one use?

I am not a moulder tho by watching some sand moulding i noticed u have to make another hole for air escape thats how u can get perfect shape!

I like this guy. So much more humble, and less arrogant than The Hacksmith.

"Its recommended you heat up then cool down the crucible to prevent cracking, but aint nobody got time fo dat!" *crucible proceeds to crack in half*

UMMM ISN'T IT OBVIOUS YOU SHOULD JUST MAKE A ICE POKEBALL... LIKE👍 SO HE CAN SEE IT

To avoid bubbles in your sphere castings you need a small secondary hole at the top of your mold for the air to escape as the metal fills the mold and plugs the primary hole

1:1 mix of Plaster to Silica powder will give you a mold that withstands heat better. Use a respirator and mix outdoors. Also add a larger funnel onto the pokeball you use for the mold so that you have a smoother pour and a slant for gases to escape while allowing enough overpour to combat shrinkage.

CHOCOLATE POKE BALL!!!!!!

You should have a mould made for your own head, then turn it into a gummy head.

Yes, vent gates are a must. more than 1 would be a little better. depending on the size of the casting, and the location of the pour gate.

Not sure if it would be the exact same on a larger scale but when casting gold crowns in dentistry we use Investing stone surrounded by a metal case. After the investment sets around the wax pattern it's heated to 1200 degrees for about 90 minutes and then the gold is cast. Possibly the material you use to invest your pattern or the heat of the oven could help with the cracking.

Cast your Logo

It would be cool if you could cast a Rubik's cube...

you need to make some kind of vibrating table for when your casting

I don't know if it's been mentioned but to slow heat treat the plaster on low heat then work your way up to 400 degrees. My friend make some pokeball but with a two piece mold, he said the slow heat made better results.

Can you pour a 3DS into silicone and create an 3DS chocolate treat ???

You know what whold be cool? a christmas-tree!

Hi Grant, In order to do an aluminum casting you'd need an investment mix which is usually 1 part sifted play sand with 2 part plaster and 1 part water or so, mix up well and pour over your wax. I've also re-enforced my investment with either chicken wire or fiber glass tape. When you melt the wax out you should fire it in a kiln or oven at a couple hundred degrees to melt out the rest of the wax and dry out the investment. These are my suggestions let me know what you think!

I got so nostalgic when you mentioned the Technodrome. xD

Make a captain America shield

*✌ Congratulations to Mohammed Ali Vader Ali from Manama, Bahrain who won the Desktop Punching Bag* (goo.gl/puDRw3) *from VAT19. An email has been sent for you to collect your prize. Winner Wall of Fame:* goo.gl/RdGLqH *The contest is now closed. If you missed it, learn how to get in the next one:* goo.gl/BkXQZL *For an even better chance to win, follow me on Instagram:* instagram.com/thekingofrandom *& Facebook:* facebook.com/thekingofrandomfanpage

To allow air to escape you have to dig a whole on the top and connected to the whole inside (where the poke ball is being cast) from the side.