# Anyone know how to turn a plastic part into a metal part?



## jimtyp (Jan 2, 2008)

I read an article a while back about a fellow that turned plastic parts into metal parts. I can't seem to find my reference for that. It seemed like he put the part in something and then the metal literally vaporized the plastic part and filled the void with metal. 

Has anyone done this or something similar? I know folks can machine a part from a diagram, but for single parts the cost would be prohibitive for me.


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## rkapuaala (Jan 3, 2008)

I've heard that one requires the sorcerers stone in order to turn lead in to gold,,, I suppose it would work for plastic.


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## vsmith (Jan 2, 2008)

I suppose you could use the plastic part the same way lost-wax casting are made, namely encasing the part in casting clay with tubes in such a way to drain away the plastic when its heated and it melts the plastic away, you would probably have to raise the heat slowely as not to cause the plastic to burn, once the casting is free of the plastic just plug the drain holes and fill with molten metal, then break away the casting clay once the metal has set. 

Persoanlly I think it would be easier to make a latex mold of the plastic part, cast that in wax then repeat the above prodess, be less messy in the melting part, and you would have a master mold in the latex to make multiple castings.


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## Torby (Jan 2, 2008)

I was going to suggest Alchemy, but rkapuaala beat me to it.


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## rkapuaala (Jan 3, 2008)

Victor, 
I've done lost wax castings before, and don't think that would work. For one, the wax used actually evaporates and leaves no residue. Plastic would not evaporate at those tempratures, you would need some sort of chemical reaction (not to be confused with Alchemy . I would guess that its something like nickle plating, but where is the metal is only electro plated the chemical would bond the inert metals to the excited plastic molicules?


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## 3lphill (Feb 22, 2008)

Sir,
Given the caveats that it has been 23 years or more since I have made any jewelery, and casting was not my primary interest, I recall that you could sprue up a plastic (or plant) thing with wax rods just like a wax and invest it in plaster. After the plaster has cured and dried it is put in a burn out oven that heats it to relatively close to the tempeture of the metal. The original wax or plastic should be totally consumed. The metal is injecting into the mold while the mold is still very hot, in fact we were taught to direct the flame of the torch across the metal in the crucible and into the opening of the mold to keep it hot. The fun part was releasing the spring loaded centrifuge and hoping it all stayed were it belonged. To get the part out of the plaster the mold flask was dropped in a bucket of water. Instant plaster chunks. If the first one turns out good it could be used to make a rubber injection mold to turn out wax copies. 


Phillip


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## rkapuaala (Jan 3, 2008)

Phillip, 
I defer to your knowled since mine is 38 years ago since last doing wax casting. It was also for jewelry, but since we did the pasters in wax blanks and wax rods and didn't use centerfugal methods, I think we did it more primitively and the instructor didn't tell us about plastic. 
We did do something that was interesting though, in stead of centerfugal forces we used steam pressure to inject the mold. Supposedly this was a process that the Egyptians used. The plaster mold was first placed in a kiln so that all the wax was evaporated. Next the cooled down mold was placed on a stone, and metal ingots (gold or silver) were placed in a bowl on top of the mold and melted. The mold was made in an old tin can (I'm sure the Egyptians didn't use those) and prior to melting the ingots a peanut butter jar lid had a wooden handle screwed to it and an absorbant fire retardant material was placed inside the lid (Don't think the Egyptians had those either) the whole lid was set in a bowl of cold water while the ingots were being melted. Once the ingots were heated the lid was slammed down on the mold and held firmly in place. The resulting steam forced the molten silver/gold into the mold instantly. 
We had two choices for removing the piece, dunk in water and let it melt, or simple remove the plaster from the can and crack it open. I did about a dozen rings using this method and a couple of pendants and charms. I got pretty good at it, but like I said that was 38 years ago.


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## Torby (Jan 2, 2008)

Saw that steam casting method demonstrated a few years ago. Was pretty slick. I was going to say cool, but that didn't seem right.


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## rkapuaala (Jan 3, 2008)

Yep, slick and economical and very clean castings too.


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## rwjenkins (Jan 2, 2008)

I stumbled across this website a while ago while looking for info on custom brass casting... http://home.onemain.com/~thebackshop/plastics.htm

I haven't tried this technique, or used the service offered here, but I did save the link for future reference.


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## jimtyp (Jan 2, 2008)

I appreciate all the info, thanks to every one. Very interesting discussion. I'll have to check into wax and steam casting. 

Richard J., that is the link I was referring to but couldn't remember it. Thanks!


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## rkapuaala (Jan 3, 2008)

Thanks for the link Richard that was a very interesting read. So it looks like its limited to styrene and delrin, but still that is pretty amazing to know


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## livesteam5629 (Jan 2, 2008)

Dental labs have been using a form of plastic to make metal dentures for years. They mix a resin like material and pour into a rubber mold then take that part and put it into casting plaster. Burn out the master in a burnout oven then cast back with molten metal. A dentist and I tried it with epoxy masters one time for some HO stuff. Ran everyone out the dental clinic with the odor. Never did it again. The Colonel kept trying to find out what had gone on but no one was talking. Precision scale uses lost plastic casting techniques as did ?? (cannot remember the mfgr) to make brass Porter engines from Grandt line plastic parts. 
N


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## Dave F (Jan 2, 2008)

Talk to Manfred (Lotsasteam)... I'd bet he couild tell you a thing or two..


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## Bob Starr (Jan 2, 2008)

Having been an active jeweler for the past 40 some years, I guess I can say a few things here. Anything that can be burnt out in an oven, a kiln, can be used for a casting. The trick, of course, is to have enough heat to vaporize the object. As a testament to that I have a belt buckle I have worn since I was in my 20's that I cast a salamander in silver. (I froze him first) I have done pine cones, bumble bees, you name it. There are many ways to cast and you have not said what kind of metal you want to cast in. Tell us what you want to do, and it is possible you could only need to sand cast or even work in cuttle bone. Depends on what you are casting. Does it have undercuts or a lot of detail? If it doesn't there are ways of making the part without the necessity of lost wax techniques. Give me some info and I can get back to you.


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## rkapuaala (Jan 3, 2008)

Bob, That's amazing, could you show us a pic of your belt buckle?


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## jimtyp (Jan 2, 2008)

Bob, I was hoping for something like brass, copper or something I could solder. The first part I'm looking at casting (or having cast) is an I-beam for a G scale bridge - about 12.5" long by 3/4" wide. Plastruct makes one in black ABS plastic but I wanted one (well several) in brass or some metal I could solder. Other parts I've made from styrene are smaller but I would like them in metal for soldering.


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## Bob Starr (Jan 2, 2008)

Hate to say this you, as experienced as I am I would not even consider casting a 12.5" I-beam. Not doable without some serious equipment that is generally beyond home craftsman capabilities. The biggest crisis that you would faace is that the metal would cool and solidify long before you could fill the cavity of the mold. Not to mention that you would need a flask, the device that holds the mold to be plus fourteen inches long! Way too specialized to do in a home workshop. If I wanted to build I-beams, I would construct them by soldering them together with hard solder, but that would require that you make some sort of jig to hold the pieces together as you solder them. I have a bridge on my layout that I built the beams out of steel and welded them together, worked fine. Here is a pic of the belt buckle. The "lizard" is cast and the rest of the buckle is fabricated out of heavy silver sheet.


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## ConrailRay (Jan 2, 2008)

Bob, not to offset the thread, but more pics of your bridge please!! 
-Ray


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## Bill Martinsen (Mar 4, 2008)

For parts smaller than I-beams, try this site.


http://home.onemain.com/~thebackshop/plastics.htm

Bill Martinsen


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## Matt Vogt (Jan 2, 2008)

Posted By ConrailRay on 10/31/2008 6:29 PM
Bob, not to offset the thread, but more pics of your bridge please!! 
-Ray 

Here, here! I love the look!


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## Bob Starr (Jan 2, 2008)

Here is a pic of the bridge when I first built it around 1994-95, maybe earlier, don't remember. It was on the Cedar Gken Nail Road. (All the people were made out of horsenails). The bridge was not used on the second layout which burnt in the forest fires of 2004, but it survived. The forest fires caused it to rust to that patina and that is how it will always stay. It is a fully functional pin truss bridge, built just like the real one. Many live steam engines have run thru it.


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## BigDigger (Jan 3, 2008)

Bob,

Thanks for taking the time to post the photos. The Lizard buckle is cool, especially because of how it was created.

Wood is my prefered medium but that bridge really has me thinking about working more in metal !

David


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## 808Morgan (Oct 30, 2021)

Turning Plastic Into Metal


Here at printedsolid.com, through the use of a mix of dark magic and science, we have discovered the secret to turn plastic into metal. That’s right. We’re modern day alchemists. Alright, maybe that’s a bit of an exaggeration. We have been experimenting with using 3D printed parts for...



www.printedsolid.com


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## Greg Elmassian (Jan 3, 2008)

Got anything for turning water into wine?


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## armorsmith (Jun 1, 2008)

Is anyone else going to the link posted and either getting 'can't get there' or going to a One Main Financial page?


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## Greg Elmassian (Jan 3, 2008)

No, it takes you to a site named like the link is named...

Here at printedsolid.com, through the use of a mix of dark magic and science, we have discovered the secret to turn plastic into metal. That’s right. We’re modern day alchemists. 

Alright, maybe that’s a bit of an exaggeration. 

We have been experimenting with using 3D printed parts for investment casting. Investment casting is not new. It is a manufacturing process where a part or artistic piece is made in a soft/low melting temperature (wax and foam are commonly used). That piece is then coated in a ceramic slurry (kind of like plaster of paris but with other stuff added in to make it stronger and more heat resistant). The slurry is cured until it is hard and strong. The original part is then burned out or melted out. Now there is a hollow cavity in the shape of the part. Molten metal is poured in and you ‘magically’ have a copy of your part in metal. This process allows for reproduction of very fine detail. 

So, the process is not new. However, 3D printing is (relatively) new. It turns out that some common 3D printing materials (PLA in particular) also work really well as originals for investment casting. 

We have partnered with a local casting guru with the goal of eventually offering lost PLA casting as a service. We will offer three different options. 

1) Send us your idea and we design, print, and cast

2) Send us your stl file and we print and cast. 

3) Send us your 3D printed PLA part and we cast. The ‘Maker’s Special’.

Some of you may be reading this and thinking, ‘why would I have someone cast for me when I can do all this myself’. For you makers that are not afraid of molten metal (I have to admit that I am) we will be starting up a blog with the lessons we learn as we perfect this art.


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## Exador (Jan 24, 2020)

I had created a 3D model driver for a coronation class 4-6-2. About 3 inches across. I put it on Shapeways and was quoted $98 for a steel print! $98 for one wheel? No thanks, shapeways.


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## Pete Thornton (Jan 2, 2008)

Exador said:


> I had created a 3D model driver for a coronation class 4-6-2.


Well, Slaters Plastikard have a 6' 6" Princess class wheel. Only 50+ GBP each with crankpins.


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## Exador (Jan 24, 2020)

Thanks Pete, those are really nice. Truth be told, even at 1:32 it wouldn't make a single curve on my layout and would be a static model so 3D printing will suffice. I am just finishing up a standard scale Clyde Puffer for the layout and the pool! I'm trying to decide if I want water in a small lake or wrap it in plastic and press it into a painted concrete lake. When that's done it may be next.


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## justme igor (Aug 9, 2020)

....


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## rkapuaala (Jan 3, 2008)

Wow, long time since I made that response. Since then I've purchased an electric foundry and sand casted a few parts.


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## Scott (Jan 29, 2008)

This is the way. 

Use the 3d print plastic to make casting masters. I'm looking to cast in whitemetal and eventually brass.


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## rkapuaala (Jan 3, 2008)

That's right Scott.








I had to do some slight modifications to the prints to cast them. Sand Casting is the way to go on some of them because there is no need for a burn out copy and the nice thing is:








With sand casting you can use the same print over and over again. If you've looked at the price of wax resin you can easily calculate the cost difference between burn out blanks and reusuable blanks. Even the sand is reusuable.


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## Exador (Jan 24, 2020)

Rubber for making white metal molds:








375 Rubber for White Metal Casting - High Temperature Moulding Rubber


375 is a high temperature moulding rubber for casting white metals. It sets hard and offers protection from contamination and vibration




sylcreate.com


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## Scott (Jan 29, 2008)

Moldmax 40 rubber to make reusable molds for whitemetal casting. Delft clay is good for larger item's and other metals ie brass, aluminium, bronze. With greensand or delft clay it needs to be rolled or broken up to re-use. Plus any burnt materials removed and discarded.


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## rkapuaala (Jan 3, 2008)

Scott said:


> Moldmax 40 rubber to make reusable molds for whitemetal casting. Delft clay is good for larger item's and other metals ie brass, aluminium, bronze. With greensand or delft clay it needs to be rolled or broken up to re-use. Plus any burnt materials removed and discarded.


I've used the polybond to do low temp castings.








Sand casted: Rt wheel is tin 550 F and the left is fields metal 175 F. It's also used for casting jewelry. I'm using the extra fine, like the jewelers do. You can use a sieve to break it up, or your hands, and the burnt stuff is minor, and a little bit mixed in with the good stuff is okay. The trick is packing it tight. It should be rock hard before you're ready to move to the second half or cast.


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## Exador (Jan 24, 2020)

Greg Elmassian said:


> Got anything for turning water into wine?


Grapes???


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