3D Print to Metal Casting. Higher Level Lost PLA Casting Experiments. 

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As someone that has done many dental castings , here are some suggestions. 1. Wet the pattern with soapy water (we call that debubblizer)and then dry it to help the water based investment "wet" the pattern ( water does not want to wet plastic). The investment will flow onto the pattern better. 2. Vibrate the pattern as you paint the investment onto the debubblized pattern and then vibrate the casting ring as you fill it.

i have absolutely zero desire to get into this type of hobby but i LOVE watching your vids. keep it up.

once again killing it with the tshirt game

Always interesting to watch my friend👊🏻😁🍻 that double cylindrical mould at the end is pretty cool .

CitriCal! Blast from the past. Paul Harvey used to advertise for CitriCal. I can still hear his voice saying the word.

I really enjoyed this quite a bit. I did learn one major thing. You sir are extremely patient to keep at this. Talented as well. Thanks for sharing these videos. 😎

That t-shirt is great

Tshirt is right up my street 👍

I've known about and loved your channel for years. Didn't realize I wasn't subscribed. My mistake.

Your vids are usefull, you share the knowledge in a practical way that is very entertaining. Thank you.

Polymaker is made for investment casting . Leaves no ash .

Good video! I've also spent some time experimenting with lost PLA and lost wax and here are my 2 cents. Let me know if you have any questions. 1. You learned by the end that the part orientation is very important. I don't think the horizontal orientation would work very well because the metal cannot fill properly as it will trap air bubbles and break apart... I was happy to see you got a good result with the vertical orientation at the end of the video and I think that was crucial. Always make sure you have your fill at the bottom and your vent at the very top. 2. Like you mentioned, a real crucible (not a tin can) helps a lot. I've found that stainless steel at least 1/16" thick is best as it doesn't oxidize and flake apart which can allow the plaster to move. Keeping the plaster contained will prevent it from cracking. 3. For larger castings, you can add boric acid to the investment to stiffen it. This will absolutely work and prevent it from cracking even with quite large castings, but the downside is that the demolding becomes a lot more tedious as the plaster hardens like a rock and is difficult to chip away from the part. You can find the ratio to use online. 4. It seems your 3D printer is underextruding a bit which is leaving that fragile pattern that the plaster fills into. You should run some calibration parts for this, usually single wall thickness works. You can also use an SLA printer with special wax-like resin for ultra detail, which I've used for jewelry. The machines are only about $200. 5. A bit of windex spray added to the plaster can act as a detergent (?) and prevent the bubbles from forming around the letters. I'm not sure how much it helps but it seems to reduce the tendency to form these bubbles. 6. I've tried pressure casting like you did but with steam and never had good results. You can instead pull a vaccuum on the bottom of the flask which is what I do. Using a sheet of graphite on top of high temp silicone on top of an aluminum manifold hooked up to my vaccum pump works well for me, without spending lots on a fancy casting table. 7. (EDIT): I also use a burnout kiln with a raspberry pi controller to precisely ramp the temp during drying/burnout to prevent cracking. This is very important.

always a pleasure when you upload a video

I think you need to spray some water and soap mixture on your mold to reduce the surface tension before you put your plaster in. By doing this your plaster will flow better against your mold producing a better detail molds.

This is a very fun series

I think what you could do is, use just a small amount of plaster to cover the top surface details and then mix 1:1 ratio sand with plaster to fill in the rest. You should also probably burn out the plaster for longer to absolutely make sure there is no water trapped.

Great video

Yeah that CSC seemed the way to go. Great videos!

Thanks for great content!

Fired it up! Thanks, man. Great videos. 🌲🌳🌲

Great Video!! 👍

this stuff is really interesting!

Thanks for sharing!!!

I love your vids Thanks!!

could you use: Resin 3D Printers 3D printing in extremely high-detail is what the 3D printers in this collection were made for. Whether it is for dental applications, castable jewelry designs, prototype 3D printing and more, this group of 3D printers is capable of incredibly detailed 3D prints. With resolutions of only 25x50x50 microns, 3D prints come out looking lifelike without the need for post-processing. Using various resins, 3D prints can be firm, flexible, soft or incredibly tough for almost any application under the sun.

Welcome back

This was an excellent sequel. I like the investigation into the internal of the mold after loss casting. The most entertaining part of the video, was watching the vacuum chamber happening before the mold pour. I'm thinking it should occur after the mold is poured, not before.

some stuff i've seen help in the past with the printing pattern in the plaster is sanding the print itself before casting

I found adding sand into the plaster mix reduces the cracking of the plaster a lot. I usually add twice the amount of sand as I do plaster. Plaster is unstable during the burnout but sand is completely inert. It makes the mix more porous which allows the steam to escape the plaster mix as it heats without cracking your mould. I just use regular play sand. It doesn't effect the detail of the casting either.

I forgot to mention to make sure your cast has good functioning vents placed in the proper position!

Very interesting Somewhat chaotic

I use a 50/50 mix of ordinary plaster of paris and sand, pore into a metal can and turn upside down to burn out the pla so it drips out on its own before burning off......heat slowly in the kiln to avoid cracks

Just spitballing a couple of thoughts (I've never done this type of casting with these types of materials): Thicker walls on the flasks might help; the investment material and the plastic and the metal and the flask all have different rates of expansion and contraction - you might be able to find an investment material that is more conducive to these things; have you tried burning out at a slightly lower temperature for a longer time? Possibly this would counter-act the rapid expansion/contraction and (possibly) help with the cracking problem. As I said, I'm not an expert at all, it's just some thoughts that came to me. Great video!

One thing you could try if the pla expanding is causing the cracking you could try dissolving it instead like abs and acetone or polymaker makes a filament called polysmooth that dissolves in alcohol maybe even pva it might hold up in the moisture long enough for the plaster to set

Many books have been written about what I don't know about metal casting! I did stumble across a channel by the Veg Oil Guy who seems to have this process down pretty good. Might give him a watch or two.

Hi, a number of people use chopped fiberglass strands to reinforce the plaster. Personally I find it a bit of a pain. I had some luck by getting ceramic fiber paper, adding water, then blending and then adding the resulting mush to the plaster mix. The fibres seem effeive in reinfcing the plaster.

Do you remember the burnout cycle you used? That has a significant impact on the durability of the prestige oro

also, since you recycle metal the way you do for the casts, could impurities/hidden reactions have influenced the quality of the casts?

I feel like I saw a video where a surfactant like Dawn was sprayed on the surface before pouring the plaster. I believe it helped the bubbles release from the surface.

Maybe it was not crosshatching from the print but rather brush strokes from the brush you used while the casting material was wet. The brush brings small air bubbles and the hair left voids? Just a thought

Thanks for sharing. I had a question about your robinair vacuum. Will it pull down to -30 or better? Thanks.

So leave slits for air flow in objects like the d and Os, cast it on its side like you did for more aluminum pressure. The sprue placement must have helped with air flow leaving as metal comes in. you could do the bottom fill and the vent at the too method. I liked the rectangle housing. try vibrating before setting process. Let your metal cool before putting into water. make the details potrude from the face more.

Maybe: 3D print into Silicone molding -> then Casting Wax and then that into Plaster

You could try to smooth the print with an isopropyl alcohol vapor chamber to cut down on the print lines.

At Master Carr you can buy raw material and you can get thick walled pipe in short sections, sold by the foot, just drill out your holes and weld on end cap which was the two crossbars.

Just want to share my experience from a bit different application that you might want to try. I did some differential hardening of Japanese style blades many years ago and had many issues with the clay cracking and falling off the blades when heated. Then I added a little borax to the clay mix and that made all the difference. I preheated it in the kitchen oven to dry it through before heating it in the forge. And after the preheat it got a slight glassy feel to it like if the borax where melting into the clay and made it more ductile while hot.

I got dap plaster of paris, hopinf it works well cuz its more like that ultracal that you use, its super hard so rubbing fingers on it doesnt destroy the small details, but i have yet to put it in the smelter to fire it, i dont have any other way of melting the wax out, but i was gonna do it without an extra container, glad i watched this first cuz id have probably had an accident and spilled the metal.

I got a tip for farmcraft101: Mix into the plaster the red shavings they use to clean concrete floors. The stuff they sprinkle on a concrete floor & sweep by hand using a push broom. Your molds won't crack & they'll last a long time. ( In between college classes I had looked up an art professor to ask him how to make strong, durable molds to cast lead & pewter. Looking back, I didn't know to ask him two part mold or onetime mold. I was thinking like a top mold half & bottom mold half, strength, & durability. Anyway he gave me this tip & I had no cell phone back then. Once online I could not find this industrial cleaner. Amazon & Etsy were not around back then. Sometime later some smartypsnts latchkey kid slipped into my home & stole all 2 lbs of my lead & pewter bits & nearly cleaned out my kits into ruin. I really hope he/ she rots in a cell some day. 🤬 ) Anyway, I will never be able to use this great tip from a master ring maker. Best regards.

Have you ever tried electroplating the surfaces to get the fine details to stay better?

Hi, I really love your videos. Don't know if it can help you, but just watched another guy video who uses Ultra-vest investment...but he also mentioned to pour hollow mold instead of solid ones.

vacuuming is one part, the other is vibrating the mold before it settles to mitigate the movement of bubbles from suspension

The cracking makes sense to me. If your mold is about 125mm across, 68um/m/K expansion of PLA means your mold goes from room temp to glass transition temp and gets about 0.5mm bigger inside a fully rigid plaster mold. Only above the glass transition temp can the PLA start to flow and "get out of its own way" and even then it won't be molten until it expands even more. I wonder if large items would work better printed out of a soluble material (PVA in water, or ABS in acetone) so you could remove most of the material before the burnout

You could try putting some sand in the plaster what should help with the cracking

Commenting for the algorithm.

i wonder if no infil and use the function "ironing" in the slicer to smooth out the skin would help

fookin legend

Whats about printing the item with low to zero infill, as few outer shell layers a possible, and then burning it out with the molten metal? When the molt goes in from the bottom, and there is an air vent on top, it might smoke like hell, but evaporate all the PLA?

One thing you might try to get rid of the 3-D print layers. Is to put them in an acetone vapor chamber. This will smooth over most of the print lines.

Some kind of vacuum when pouring might help too?

Not sure how much time you allow for the phosphor copper reaction because of your editing but when you had an image of the bag with the phosphor copper shot I though it said leave it in a minute or so, I counted much less time than that on your first pour for the video.

Could putting the casting on a lazy Susan and spinning it help. Centrifugal force is quite potent

Can you do experiments to see the flux effects on castings?

Have you tried to let them set longer to push out all of the moisture?

This is good but have you thought of standing the cions straight up ?

Is it ash from the pla that is causing the fill in the letters? Blow out with air maybe?

I can't tell, but are you baking your plaster molds before firing them? You need to remove the moisture before firing it to a high temp.

try reducing the infill. maybe have no infill, make it hollow, and use the support material function. this should let it collapse inward when expanding.

thanks for the tips! btw, theres no link where you pointed to and said would be a link lol u maybe forgot? just letting you know

Do you heat gypsum before pouring?

Is it possible to dissolve the pla in acid instad of burning it out?

is it possible to do a extremely low infill and skip the burnout process?

i use drywall joint compound onto very thin walled pla printed models and i dont even have to burn the plastic out, i never have cracking issues my main issue in my 2 small tests so far was simply that my brass cooled too quickly to completely fill my mold. i didnt have any gates or sprues or vents etc. i literally just coated my part and then mae a hole in the coating to pour into. my next test i will use slightly higher melt temp + a riser because i could see on my test part where the detail was better towards the bottom and i tihnk its just the weight of the molten metal.

Why did you VC it before pouring? I always pulled my vacuum after pouring and it's the way to go I think

3:50 What value do you vac this to? I have a pressure kettle I plan on using and I want to get the right vac pump. Thanks!

have you tried casting a wax from the print and then metal from the wax?

You put the mixture in a vacuum which is cool, but could the mould itself fit in the vacuum chamber after you've poured the plaster? I'd be surprised if pouring doesn't trap air EDIT: Ignore me, I got to 10:15 now where you've tried exactly that.

I'd like to see an AR lower receiver made this way

Pressurizing while the plaster sets shrinks the bubbles by a factor proportional to the absolute pressure. Thus if you pressurize at 20PSI which is 20PSI "gauge", or 20PSI above atmospheric, or 35PSI absolute, the bubbles will shrink to 15/35 or about 43% of their original size which is not really much of a reduction at all. Also, unless the pressurized air can diffuse out of the mould before or during firing, it acts as an force trying to expand and crack the plaster. Applying, then releasing, vacuum before the plaster sets causes the existing air bubbles to either expand and break off completely, or to be replaced by bubbles of water vapour, which condense to essentially nothing when the vacuum is released. I'm not sure how the air trapped in the 3D print's infill affects all the vacuum/pressure. It may depend on whether the skin of the 3D print leaks. It is almost certain to have a few leaks, but it may also be the case the the entire skin is leaky all over.

I don´t understand what is the pressure pot supposed to do ? Usually you do that to get rid of bubbles but you already have vacuume degased your plaster so wjhat´s the point ? Also you ddin´t seem to have any problems with bubbles anyway.

If you think that the print is expanding too much, try printing with the coin rotated in the x or y axis by 45 degrees... It's not a magic number or anything, but I think the problem is that you are printing flat on the bed when it comes to it being too solid. There would be a lot of support material with it rotated, but you probably have 1 or 2 non-solid infill layers as it is. Printing with it wonkey will just leave you with almost all walls, and little solid layers. I have noticed printing in that orientation will increase your surface details and reduce stringing on the surface. Maybe hit it with clear coat to seal it. And yes, it does take forever to find out if it's good or not If that is the same color change pla I use, excellent choice. That stuff is good beyond it changing color

ive only recently gotten into metal casting, i havent been able to properly cast things yet, (waiting on shipping) so take what im about to say with a teaspoon of salt, i think sandcasting might be the move for this stuff, and im curious as to why you arent doing that instead, but again thats just from what ive seen other people do online, and maybe im incredibly wrong.

I'm guessing The reason you're seeing much taller ridges on the inside of the mold is that the plaster is soaking into the cracks in the PLA

Moroso makes a ceramic block sealer (to seal cracks in auto engine blocks -) which (when fired to hi-temp -) should be ideal for sealing cracks in your investment molds .

Thanks for trying to use pressure, I get the impression that 60psi is a good starting point for epoxy applications. I wonder if the prestige oro is plaster of paris based, as that goes the same way (delicate and friable) when you heat it. The ultracal looks like it properly cures, but also expands as well which is why it cracks like that - something I don't think plaster of paris does as badly

My father worked at an investment casting company. I used to have the name of the investment casting ceramic they used. I know there they would use molds to cast the parts out of a casting wax that they later burned out. The shells were several layers of ceramic slurry dusted with silica sand after each wet coat. You may be better off printing a 2 part mold of the item you want to make and then making wax copies to put in the plaster that you burn out.

The pressure pushed the air out of the 3D printed model.

Wax also expands when heating, that's why they use wax in wax linear motors. It produces a lot of force.

So what might help with PLA is rather than doing a conventional burnout to have the mold be upside down and only bring it up to 450 at first, letting the pla go soft enough to drain out somewhat. The plaster already has its final shape at this point and staying below 500 for the beginning doesn't cause the chemical change to the plaster of breaking the water molecules off. Then after you've gotten a bit of the pla out, you can take it up to full burn out temp. Or possibly try casting it, as the metal should burn the remaining thin layer of pla off and if you have good vents it might work

Maybe after this we'll see an upgraded version of the cannon?

I need a aluminum bracket made. Are you in US and can you cast a bracket for me?

what's the life of a crucible? IE how many pours, and is there a way or even a reason to get all the slag off/out of the crucible?

👍👍👍

I dont understand: Why did you create a lost form and not forms with 2 halfs for the coins?

Did you ever try adding sand to the plaster? To keep it from cracking?

Enjoy your videos. I'll give my stab on a coin like this but via sintering. Got a few vids on my channel showing some other tests if you wanna check

It’s not air bubbles it’s residue from pla not burning out completely. Ash or plastic stuck a the bottom

Less water in your plaster will lessen the cracking, as little water as possible to get your detail

At around 6:30, you made pour with no vent. Is that the way it's done?

what does the phosphor do in the alloy?