The EASIEST Method for Metal Casting (open mold)

[@Chlorate299]

Jewellers sometimes use cuttlefish bones for casting. They're made mainly of calcium carbonate but the structure is soft, you can press the pattern directly into them.

[@PaulsGarage]

That's interesting I didn't know that

[@mytoolz]

Good to know thanks

[@Boosted98gsx]

1:53 MAKE SURE you sand smooth your 3d printed "drafted" sides, otherwise they'll still grab sand. Notice the ringing in his print, that needs to be SMOOTH.

[@PaulsGarage]

Good point. If you want to do anything good definitely sand it. I was less concerned here and got a bit lazy

[@paulkurilecz4209]

Those bubbles? That is why a pouring basin is used. The Aluminum alloy used for beverage cans is a 3000 series and does not make a good casting metal.

[@PaulsGarage]

Bingo. Basin and spin trap ftw

[@lazytommy0]

What metal is best for casting intricate designs then? 😮

[@paulkurilecz4209]

@@lazytommy0 If you are wanting to cast in aluminum, the alloy to use is A356. A good source of A356 from scrap is aluminum car wheels. If you want to make a close alloy from scrap beer cans, you will need to add Silicon. To do this go ahead melt the beer cans and pour into ingots. Clean and weigh the ingots. Remelt the ingots and add about 7% by weight of Silicon. This will be close to A356 when starting from beer cans. The trace amount of Manganese from the beer cans shouldn't affect the castability. Be sure to use a flux and to stir the melt when you have added the Silicon. Another thing that is helpful on intricate castings is to increase the superheat or temperature of the melt above the melting point of the alloy. This helps to avoid freeze outs and cold shuts. Also, there is a minimum thickness that can be achieved when casting. Preheating molds prior to casting can also help. hth

[@ellizaethe9249]

This was an amazing explanation of why's and why not's, do's and don'ts. I loved that you showed your mistakes and your experimentation and what resulted from it. That was a lot of work, and it is very appreciated. Thank you.

[@Mistertbones]

I love your self-deprecating sense of humor in all of the videos.

[@PaulsGarage]

Thanks!

[@randolphchappel6098]

What I found with flat casting is to make a cover to go over the cavity. I took a piece of MDF; drilled a hole through the Center of it; then used a chamfering bit to creat a funnel. Then I cut it in half. Then placed the 2 halves together over the cavity. Lightly clamped the pieces down over the cavity. Did the pour until the molten metal rose into the chamfer. Waited for the metal to harden; pulled the two pieces off and with pliers lifted out the casting by the chamfered plug. With yours make the top pieces out of some type of metal, I guess. I’m casting pewter with mine; over a Smooth On flat mold.

[@bola9452]

dude your sense of humor the best

[@makofett7404]

We used ladles in the foundry. Pour slowly but steady from above. Have to have a vent and srop when you see the pour opening and vent filled. Make a board. or metal top plate with your holes since you cant make a backside sand mold

[@steverenken5143]

I was thinking of doing something similar with some cookie tray trains using plaster of Paris to make a positive cast. But instead of covering the whole back side, I was thinking of using tuna cans filled with sand just to cover that area, and dig the channels, and build up the poor, and exit holes on each side of the can.

[@jackdawg4579]

Why do I love make open mould castings - When I am making billets to feed my lathe and my mill. Not looking for fancy surface finishes or detail etc, just want a billet of metal to machine. A 100mm of 80mm diameter aluminium from my nearest metal supplier is about $50 delivered... shove some cans into some green sand, fill the resulting holes up with aluminium and I am good to go for a fraction of the price.

[@1pcfred]

That must be some really nice aluminum if it costs that much. Your little puck only weighs about 3 pounds. So they're charging you $16.67 a pound. Someone where you order metal from is driving home to their mansion in a really nice car. Currently aluminum is worth about a dollar a pound.

[@PaulsGarage]

Yeah scrap is basically free. I'd be worried about porosity and bifilm entrainment with open molds though. Weak spots you can't see until it cracks. Of course you can just overbuild stuff like me and then it doesn't matter 🤣

[@simoncleret]

I'd like to see the results you get if you use that zinc alloy in silicone molds

[@gregorychaney7604]

That would be very interesting!

[@PaulsGarage]

Well then I have to try it!

[@samwilliams8327]

Would most likely need slightly higher magnesium content. Used zamak5 and 3 for silicone casting, lacks the flow properties required for perfect castings

[@brandimurphy2160]

Thank you for all the advice! Just got some from that company. Wicked fast shipping. This will be perfect for making replica hardware for my antique steamer trunk hobby.

[@GregKrynen]

Rotometals shirt for the win. Have been using them for decades now... I feel old suddenly. Time to light a fire!

[@MetallyCorrupted]

Very Cool! I just started playing with sand casting, Great tips

[@sierraecho884]

You can get around the shortcomings of this mold by finishes up the pattern as usual and then clamping an aluminum plate behind it it pour 90 degree to the side. So place pattern and ram with sand in to place inside your wooden box --> turn box around and clamp a metal plate behind it --> now turn the mold by 90 degree which increases headpressure and pour as usual. You just need to create an opening on the side that´s it. But the pattern making and all that stays simple.

[@PaulsGarage]

Yeah that would work, I'd rather just use a normal 2 part mold though, then I could control the gating a little more

[@sierraecho884]

@@PaulsGarage True, a 2 part mold is simply better.

[@DavidClunie]

Any reason not going with a silicone mold? Especially if using a low temp metal. Back in the day I used to use RTV engine silicone from the automotive store but that hit took forever to dry, until I found tin base and then platinum based silicone rubber.

[@andy-in-indy]

Most high temperature silicone are only good up to around 300 C but ZA12 does not melt until 380 C. It works for pewter and some other low melt metals, but not this one.

[@PaulsGarage]

2 reasons why I didn't do silicone. #1, I don't have any (this is the main reason) and #2 I wanted this to be the "easiest" method, and making a silicone mold takes some steps. I've read some super high temp silicone can handle za12 but not for very many castings

[@n2darkness]

If you didn't want to do a 2 sided ram mold, you could scoop in a pour shout to one side and then cover the rest of the mold with a scrap wooden board and clamp it down (giving it a temporary back). But would only work if doing one casting at a time, unlike what you demonstrated here.

[@PaulsGarage]

I've seen people do that with low temp metals. It would probably work with this stuff

[@Microwavingmetal]

I read a paper form about 1904 where they add tin to aluminum to improve the liquidity of the molten pool and flow of the metal .

[@gregorychaney7604]

Tin was probably less expensive back then. It would still work but zinc is much cheaper.

[@PaulsGarage]

Aluminum in 1904 was pretty bad, yeah. Silicon is the go-to for increasing fluidity, but even some high silicon alloys (like a380) don't flow great due to the copper added for strength. Just aluminum is super weak, everything is a balancing act.

[@richardepps8500]

When will we see more of the David Gingery series?

[@PaulsGarage]

My plan is one video a month, so probably 3 more weeks from now? Video next week, stream next week, gingery after that

[@richardepps8500]

Can't wait

[@MikelNaUsaCom]

@@PaulsGarage =D

[@joshuadelisle]

Well explained. Cheers J

[@ufochannel01]

put a screw in the back or melt a small wire into the back. then you can pull it up without any flaws from your fingers pinching it to get it out. all in all great info.

[@olawlor]

6:54 Could that dull area also be a "shrink", where the last metal to solidify has lost some volume feeding the areas that froze before it, leading to microporosity? (Hmmm, you talk about shrinkage in your Zamak video, so maybe it is oxides from the pour?)

[@PaulsGarage]

Hard to say because the first one I poured had a worse dull area than the last one. The last one was poured at a lower temperature (which can reduce shrinkage) but also the crucible was emptier, so I tilted it more, pouring from a lower height (reducing entrainment). The dull spot is on the bottom, however, which would be an odd place for shrinkage *Except* with this alloy for reasons I'll go over in a future video

[@israelborrerojr9772]

Theres a movie replica badge I purchased that is out of resin. Is there a way or place to go to get it recreated a little larger and out of metal?

[@joell439]

Interesting. Nope, I won’t be doing any open mold. Thanks for saving me some time 👍😎👍

[@Marcuslobenstein]

Would pre heating the mold help like 250 degrees normal kitchen oven?

[@PaulsGarage]

Not really, the petrobond sand I'm using would have issue with it anyway. You could try heating the surface with a blow torch maybe but the key is head pressure, that's why these patterns don't work well

[@HeinrichsMade]

Any light metal as you know wont cast well open mold. No head pressure as you said. Ibe been Casting pewter with open mold casts with 100% good casts. It flows nice and its heavy.

[@PaulsGarage]

Pewter is good stuff. I just wish it wasn't so expensive

[@HeinrichsMade]

@@PaulsGarage yeah, I found some lead free pewter for $5 at a thrift shop 1.5lbs each plate.

[@PaulsGarage]

@@HeinrichsMade that's a fantastic deal!

[@Islamisthecultofsin]

Why didn't I see shrinkage of the cast items? I was thinking of making a metal casting of a plastic gear but shrinkage is supposed to be a problem. It must be exact or the metal gear will not work. Also thinking of casting it using epoxy. My thinking is that the epoxy gear would be stronger than the plastic gear.

[@PaulsGarage]

Shrinkage is a percentage thing, so small pieces like this will be imperceptible, but they do shrink. Something like a gear has to be exact, so even a tiny shrinkage will make gear teeth a little sloppy, which destroys them quickly. Most metal gears are machined from a disk, not cast in place. Plastic ones are molded in place though. I would suspect depending on the plastic and epoxy, the plastic might actually be stronger. Some epoxies are brittle

[@Islamisthecultofsin]

@@PaulsGarage I was thinking that maybe the plastics that they use to make the gear has improved and the new gear that I have ordered will be stronger than the old one. The original is probably 20+ years old.

[@UtOhh]

Hey Paul. I'm in charge of trying to figure out the best way to make a metal dragon head so that it can actually breathe fire. Can you do a life size dragon head? If so how much would that be? Ballpark.

[@PaulsGarage]

I don't make things on commission, but if I had to make a huge fire breathing head, I have an idea how I would do it. 1: get the flame shooting set up figured out. I would probably use a propane weed burner set up, that's what is in those boring company not-a-flamethrowers. 2: I would weld up a frame out of steel angle or square tube that I could mount the weed burner inside in whatever orientation I needed. Then 3: make a steel dragon head in pieces that I can mount onto the frame built in step 2. You probably want the weed burner and the dragon head attached in a way you can remove (not welded on) just in case you need to make adjustments, repairs, take apart for transport, etc... I'd probably make the head out of sheet steel. That way you can form it, weld it, forge it, etc... easily. A welded up sheet steel head would be way lighter than anything cast, and it would be much cheaper and less brittle. Steel is heavy, yes, but sheet steel is extremely strong given its weight. This video here is a casting made from zamak, and a weed burner is hot enough to *boil* zinc, but won't even melt steel.

[@UtOhh]

@PaulsGarage Thanks for the reply. I appreciate your point of view. We have the flame setup already. We are not going small. We want the flame to be seen from the space station (no exagerration. My company is an architectural company that does custom jobs. I do CAD work and operate robotic arms. My goal is to present my boss with ideas on how we can build the head so this is why I'm reaching out. Sheet steel sounds like the way to go. One of the other things I need to figure out is the cost/time options. Do we contract the job out or do we buy/make the equipment to do it ourselves. I saw your video and wanted your opinion as this is a new feat for me. Thanks again!

[@andy-in-indy]

Do you need to add a flux to zinc? If so, what should be added and how much?

[@PaulsGarage]

I haven't. This stuff flows like water. One thing I haven't mentioned yet is that za12 (and 8 and 27) is hypereutectic and can separate out, which makes it a bit unique. More on that in a later video I think. But it flows great

[@sammaldonado5931]

ah yes, metal casting videos in the morning!

[@PaulsGarage]

Smells like... Burning? At least with petrobond sand lol

[@ChaosPootato]

I recognize that lance tip you used to pull out the castings, man it's been a while

[@PaulsGarage]

That's actually a new one I cast a couple weeks ago from this same metal. I still have the bronze one but the tip is rounded a bit. I was using it as a chisel to break glass off of some firebrick and the hammering didn't do the bronze any good 🤣🤣

[@robby_6470]

hey, would you recommend any brand of sand for beginners? I was also wondering if plaster could be substituted for sand.

[@PaulsGarage]

For sand casting I would definitely say get petrobond. Plaster is for investment casting which is a totally different process. I've had good luck with prestige optima plaster but I hear plasticast is another brand that is just as good for lost resin investment casting.

[@robby_6470]

What's the difference between open mold casting and investment casting?@@PaulsGarage

[@mytoolz]

The EXACT video I needed, THANKS!!!

[@drewg.6961]

Okay I figured casting/recasting a coin would have been really super fun & easy and any and everyone can do it in their backyard. I’m not a metal worker or even a tinker er… or much of a speller if that ain’t clear lol. What I am or was trying to do was create a “recovery” coin, like as in AA/NA. Something more permanent instead of these temp plasticish coins.. and the said community here or lack there of is very overbearing against the grain kind of bunch . I was wanting to make something a little more welcoming & free roaming! Something more along the way and self care rather a strict call of duty. To each their own less fall in line. For more of a business card then anything else as you can assume the bunch I’m referring to isn’t. Inch of the business card types. So before my many failed attempts about the detail.. would it help at all to use a vacuum like the tray type ones to make plastic molds/packaging, using that in the sand? That mixed with vibration? Do u think that would help at all?

[@3rdeye7thdimension]

What if you used a small, short, steel rod at an angle stuck into the corner of the mold, and pour the ZA12 over that to reduce the turbulence of the pour?

[@PaulsGarage]

Anything to reduce the height of the pour, the better.

[@3rdeye7thdimension]

@@PaulsGarage I was thinking more of reducing that initial impact that causes the sudden deceleration of the molten liquid, thereby adding turbulence to the stream; pouring along a steel rod would also reduce the air molecules from being dragged into the pour, in theory anyway. Might try a garbage pour as a proof of concept.

[@1pcfred]

It sounds like you want him to decant the metal to me.

[@brandonfrancey5592]

Poor Martian. Doctors think it's a physical problem, in truth he is just watching Paul pour castings. Even the ones Paul doesn't film, Martian can feel it.

[@PaulsGarage]

Haha oh no I don't want to cause him pain 🤣 it hurts me a little to watch the droplets too

[@fictionaddiction4706]

Hi, I'm new at this and this is a bit off topic but I'm hoping you could answer me. Is there a way where I can make a temporary sand or plaster mold to cast a strong metal like (steel or graphite) and use that to make a permanent mold where I would later cast other metals with lower melting points and not need temporary molds anymore?

[@skyrider4789]

Can you cast a full-sized ironman helmet? I’m sure you’d get many, many, many views and subscribers. Plus, I’d love to see! 😊

[@PaulsGarage]

I imagine I could with investment casting. Might be a heavy helmet though lol I think sheet metal forming is the way to go for that

[@skyrider4789]

@@PaulsGarage cool! 👍😍 Is sheet metal forming something you do?

[@PaulsGarage]

@@skyrider4789 I have in the past but the videos don't do well so I stopped making videos on it. Most of the sheet metal I did was car related. There has to be an armorer somewhere on KZbin who has made an Ironman helmet

[@skyrider4789]

@@PaulsGarage Thanks. I have a 3D model I’m trying to get made with a metal process, but at this point, I’m not sure what process is best. I’m learning all I can. Thanks for your responses! 🙏

[@anunordinarycellist]

why do I feel freaked out that at 3:04 , has my hometown water tower?

[@jordandmytryk471]

Love your vids just found the page great stuff

[@PaulsGarage]

Thank you!

[@VincentGroenewold]

I rejoined the Patreon, I always cycle around creators but am very interested in the new projects! :)

[@PaulsGarage]

Thank you! I saw that, welcome back!

[@JoeRed]

I'm jealous of the Datsun emblem...

[@PaulsGarage]

the guy i sent that to just sent me a picture of it, he still has it! I made that thing YEARS ago

[@johnmccanntruth]

Great info for someone starting out… Only downfall was how nice the Zamak did because it flows so nicely. Probably most people would be using junk aluminum and it would have looked much worse, 😂

[@PaulsGarage]

Very true, that's why I added the clip of my old aluminum pour so people could see the results. It would be better to ram up a 2 part mold. I should probably do a video just on that 🤔

[@MashDaddy]

Sand casting has been used for 2,000 years. I think it's time for an innovation 😊

[@PaulsGarage]

Investment casting is coming. I already did a little bit I'm researching/building and acquiring equipment. Videos soon. Next video will be a precursor I guess, I have one of those temperature controlled electric furnaces now. Temperature control is super critical.

[@dfross87]

If Martin ever gets well enough to make more videos, he might ask to use that dripping pour clip as an example of "What not to do."

[@PaulsGarage]

Wait martin isn't doing well? That's not good. I hope he gets better soon. And yeah I almost put in a text joke about hearing an Australian screaming in the distance at that part but I couldn't figure out a way to make it funny enough lol

[@dfross87]

@@PaulsGarage His back is a buggered, and causing him a lot of pain. Surgery to reduce the pain level was a failure, so he's out of action for the foreseeable future.

[@PaulsGarage]

That's terrible. Back pain is the worst. I know he's an older guy but I hope he feels better at some point

[@JeremyMakesThings]

@@PaulsGarage you did put that joke in there, and I laughed at it.

[@PaulsGarage]

I left it in? Weird I thought I didn't... Maybe I'm losing my mind after all haha

[@custos3249]

A lot of channels out their use open molds, and I just don't get it. They rarely _don't_ look like hot dogshit, yet those channels also get millions of views...

[@brandonfrancey5592]

Casting swords and axes and video game weapons gets attention. Most people aren't interested in doing it them selves, they just want to see cool shit.

[@PaulsGarage]

Yeah Brandon nailed it. Cool stuff gets views. Though less so these days. Open casting is fine for making ingots and simple stuff in my opinion. The entrained oxides tend to float when it's remelted and can be skimmed off during the next pour, so it doesn't hurt much.

[@PaulsGarage]

Want to use your 3D printer to learn Sand Casting in your home shop? paulsmakeracademy.mykajabi.com/joinus

[@davidsalman8362]

Next; something that no youtuber so far has done Use the printed Polycast object as a Foam for casting, leave it under the Sand and just pour Molten Aluminium brass on it, But you'll need to pour it fast

[@lornablewettandlee504]

I don't think I would ever try casting in an open mould, unless I was just producing ingots or muffins. They look OK for some reason. Strange.

[@PaulsGarage]

I'm not going to do it anymore, I'll probably get an ingot mold though. These bars I bought are really big

[@jek__]

I think a pressurized pond is called a geyser

[@PaulsGarage]

Haha exactly!

[@Kineth1]

I meticulously scour my subscription feed. i HATE notifications from YT. Sorry, I won't turn on alerts, but I will watch, like (when appropriate) and comment to feed the alghorrorithm.

[@PaulsGarage]

Thank you! I understand gating notifications of all kinds. I should scour my sub feed more I think

[@sierraecho884]

Next Video: Casting under pressure. Cast a small delicate piece inside a small pressure pot and pressurize it right after the casting. Caution, make sure the pot won´t explode!

[@PaulsGarage]

Lol I think I'll avoid molten metal explosions if at all possible

[@sierraecho884]

@@PaulsGarage Come on give it a try, nothing should happen =)

[@Yabroproductions33]

heat your molds up prior to pouring

[@runrob1]

cool

[@AmalgmousProxy]

You should check out the channel Olfoundryman you might like it. I learned a lot from him.

[@PaulsGarage]

The text about the screaming Australian was a reference to him 😉

[@AmalgmousProxy]

@@PaulsGarage Hmm. I must have missed that.

[@Squidword99]

Bro had bill cipher

[@AnarchyAutomatons]

111th!

[@PaulsGarage]

I don't think trophies go up to #111 🤣 or id give you one

[@timhaakenson916]

MEH.. SOMETHING TO DO WHILE YOU CHASE ME FOR YEARS