Need some help from the cold casting experts.

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NakedMoleRat

Master Member
I have been working on my Sabacc set, I have been creating a bunch of different coins to use for play.

I started out doing resin casts, painting them and then giving them a black wash, but then learned how to cold cast.

I have been using brass and copper predominately. Now I would like more of a regular metal look. What would be better to use aluminum or nickel? Which will give me the better finish between those two?

As always, thank you for your help.
 

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wackychimp

Well-Known Member
Cold casting is mixing a metal powder with clear resin to create a finished product that feels metallic. Can be resin on the inside but feels like real metal on the outside.

I'm not one of the experts OP mentions, but I've looked into to specifically for making my own coins. I'd be interested to see that you come up with NakedmoleRat
 

NakedMoleRat

Master Member
What I’m hoping to find out is what will look better between the two metals, aluminum or nickel? Which one will polish up and have a better finish? I’ve been using brass and copper, now I want a silver looking finish.

Thank you.
 

lmgill

Sr Member
OK. I figured this was what you were referring to. I dislike these names, because they where thought up as strictly a marketing tool, and are misleading and false. Resin casting is...resin casting or plastic casting. "Cold casting" is a term like "Vacuum casting" that some marketing guy tried to call vacuum forming, because it sounded better. But in the end, it's just a catchy, cooler sounding name for something that's been around for years.

I have little experience with plastic cast items heavily loaded with matalic powder, and find it hard to believe you could ever get a very good polish on any of the metal powders. But I don't know how "bright" you are trying to go.
If you are making your coins in silicone, you can get metal, that melts at a low enough temp to pour into silicone molds. This can then be electroplated with nickle, silver, gold, brass and so on.
This is how we made the Goonie coins, but they used a vulcanized rubber for molds. We use Conquest industries, but they may be too big an operation to have the smaller quantities your likely looking for. But I'm sure a web search would turn up some options.
 

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BeardySi

Active Member
"Cold casting" is a term like "Vacuum casting" that some marketing guy tried to call vacuum forming, because it sounded better. But in the end, it's just a catchy, cooler sounding name for something that's been around for years.
Vacuum forming is using a vac to suck a sheet of softened plastic down over a former.

Vacuum casting is a process where you mix and pour resins or elastomers under vacuum. If you mix them outside a vacuum their offgassing just foams them.

Fast cast resins (or bench casting resins) are mixed and poured at atmospheric pressure and shot into room temp moulds and cured at room temperature.

Cold casting refers to the process used to make a metallic part without having to cast one with actual molten metal.

So no, they're not all the same thing.

As to the OP, I've not used nickel, but I'd imagine it should look great. Generally I've found polished nickel gives a nicer, deeper colour than aluminium.

Here's a tip for casting with metal - wipe your mould down with alcohol and a lint free cloth before use. Once it's dry, pour some metal powder into the mould and shake it about to coat the inside, then tap off any loose metal over a sheet of paper. Static should leave a thin coating behind on the surface. Then pour your filled resin as usual. The resin will impregnate the layer of metal and you should be able to polish it up really nicely. If you rub through any spots the filled resin behind it will keep it from looking bad.
 

NakedMoleRat

Master Member
Here is a Mando coin I just made. I used brass. I coat the mold as mentioned above and put a spoonful of the metal in with the resin as well.

I will probably go with the nickel then if it’s the best shine. Thank you.
61B2859B-7CF4-42C1-B0C3-B5AC0BE831CA.jpeg
 

NakedMoleRat

Master Member
Two kinds of resin. On the left is resin that cures white and sets in 10 minutes. On the right, clear resin that sets in 24 hours. The 10 minute set white resin I did NOT dust the mold first. The clear resin I did.

I got pretty much the same result, except it took 3 minutes to buff out the clear resin coin and 45 to buff out the white resin.
image.jpg
 

lmgill

Sr Member
Vacuum forming is using a vac to suck a sheet of softened plastic down over a former.

Vacuum casting is a process where you mix and pour resins or elastomers under vacuum. If you mix them outside a vacuum their offgassing just foams them.

Fast cast resins (or bench casting resins) are mixed and poured at atmospheric pressure and shot into room temp moulds and cured at room temperature.

Cold casting refers to the process used to make a metallic part without having to cast one with actual molten metal.

So no, they're not all the same thing.
I understand what all the terms are,
and what vacuum forming and actual vacuum casting are.
What I was referring to was an artist, who, called his vacuum forming (ei. thermo-forming) "Vacuum casting" to make his products sound more valuable, when they where just vacuum formed styrene.
This is also the origin of "Cold casting". The term was created as a marketing term, used to make a plastic products sound more valuable.

These terms are created to make some sound more appealing then their common names. Like, "Stabilized Turquoise". Which is a euphemism for chalky, soft, unusable turquoise, impregnated with blue epoxy, so it looks worth something. You can technically call it turquoise when you sell it, because, technically, it does have turquoise in it.
You can also look at "German Silver" or "Nickle Silver", and neither one contains actual silver. Because these are both marketing terms for the metal, Nickle.
 

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NakedMoleRat

Master Member
Thank you all for the likes. After I went and made a bunch of credits, painting and weathering them, I learned how to do cold casting, and now I am slowly replacing all of the painted ones. It is going to be a very expensive set for sure, but well worth it in the end.
 

funboy1013xx

Sr Member
RPF PREMIUM MEMBER
nice job, have you tried rub-n-buff? i have "kinda" learned from bit's and pieces of other post's here you can get a nice metallic polish if you practice and if done correctly it can be clear coated to preserve the shine.
 

Sluis Van Shipyards

Master Member
Do you need specific metal powder to do this? My grandpa had a big container of aluminum powder we found when they sold the house last month. I kept it just in case I could use it for something like that. Either that or thermite, IDK. :D
 

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signeddiamond

New Member
I understand what all the terms are,
and what vacuum forming and actual vacuum casting are.
What I was referring to was an artist, who, called his vacuum forming (ei. thermo-forming) "Vacuum casting" to make his products sound more valuable, when they where just vacuum formed styrene.
This is also the origin of "Cold casting". The term was created as a marketing term, used to make a plastic products sound more valuable.

These terms are created to make some sound more appealing then their common names. Like, "Stabilized Turquoise". Which is a euphemism for chalky, soft, unusable turquoise, impregnated with blue epoxy, so it looks worth something. You can technically call it turquoise when you sell it, because, technically, it does have turquoise in it.
You can also look at "German Silver" or "Nickle Silver", and neither one contains actual silver. Because these are both marketing terms for the metal, Nickle.
Ok, but why hijack a thread to air your grievance about perceived misleading advertising? They guy just wants to know what type of metal to mix into his resin not be talked down to for using very common lingo that everyone who has experienced it understands.

Also OP, I have had a lot of success with aluminum as it shines bright and easy. However it is very light. If you want shine with a bit more weight go with the nickel.
 

lmgill

Sr Member
Ok, but why hijack a thread to air your grievance about perceived misleading advertising? They guy just wants to know what type of metal to mix into his resin not be talked down to for using very common lingo that everyone who has experienced it understands.

Also OP, I have had a lot of success with aluminum as it shines bright and easy. However it is very light. If you want shine with a bit more weight go with the nickel.
It was not my intent to hijack nor offend anyone. I was not clear if nakedmolerat was to simple adding powder to resin or something else. Since it is not possible to get a true metal surface with this, I suggested an alternative.
Additionally, it has been my experience, if you know correct industry terms from marketing terms, internet searches will bring up alternatives that are not limited to the "hobby" use.
On that note,
nakedmolerat,
We use metallic powders all the time when making metal looking fittings, but the effect is limited. Now if your happy with the results your getting, and in the pictures they look about what i'd expect, then the subtitles are personal preference, an you just have to try different things until you find the combination you like.
The issue with getting the metal to look more like solid metal is most of the "Metallic" powders are microscopic flakes, and unless you get these flakes flat an aligned on the surface of your cast, then getting a brighter surface will not be possible. (The surface finish on your part / mold is also important.) This is why rub-n-buff gets a nice shinny surface is the metallic flakes in the wax base, smear down in a nice flat arrangement.
So as advised above, adding the powder to the surface of the mold is really the most effective, while adding it to the resin is going to have minimal effect, but use a lot of powder. One thing that has an effect is the color of the resin. Try coating the mold, and pouring your part in black resin, see if that improves the look.
However,
If you still want a surface you can get a better polish on, perhaps if you look for metal powder that is more granular, such as the type used for metal flame spraying, you may be able to get a density of metal, that one could actually polish.
The only way to get a true bright polished look, is to get a denser, solid metal surface on your part. Hence why I suggested of pouring low temp metal in silicone.
(Now, while the following method seems complex, it's pretty simple, and will give you a surface you can polish.)
Another way, used by museums to replicate metallic objects is electro-forming. This is where you use an conductive primer sprayed into your molds, and then electro-plate a heavy copper layer into the mold, on this primer. You end up with a thin, solid copper surface, which can be polished, and then electro-plated with any metal you want.
 

Hotshot

Sr Member
RPF PREMIUM MEMBER
Are you backing the powder with additional dye to your resin? (It looks like you are just want to be sure)
Another thing you can do is mix your powders.
Smooth On has a chart of different colors vs different powders.

your casts really look great and very in-universe! You’ll be casting beskar in no time.
 

NakedMoleRat

Master Member
Are you backing the powder with additional dye to your resin? (It looks like you are just want to be sure)
Another thing you can do is mix your powders.
Smooth On has a chart of different colors vs different powders.

your casts really look great and very in-universe! You’ll be casting beskar in no time.
Greatest compliment ever! Thank you. That’s exactly the look I was going for.

I powder the molds and mix metal powder in with the resin as well, but I have not been using dye. I’ll have to look in to that as well.

I will need to look up the Smooth On website. Thank you for that tip.
 

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