Need some help from the cold casting experts.

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Hotshot

Sr Member
RPF PREMIUM MEMBER
My pleasure! And I should have been more specific...you can mix the powders themselves to produce other metalics, myself I mix a bronze and gold to produce the correct coloring of the gold resistors on ghostbuster traps. Can’t wait to see more!
 

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NakedMoleRat

Master Member
Now in aluminum.
189962E2-2BE4-453F-918B-28E65C93DFEE.jpeg
FA7B5C1A-1C90-4A59-8227-2A49A4D0E518.jpeg
 

robstyle

Master Member
a lot of good info here. Through trial and error, in the end whatever method works for you is the method that works best.

As prior mentioned black casting material vs white casting material will yield color differences on the final part. With metal powders, the finer the mesh the finer the metal particle the finer the metallic surface finish.... Most hobby and over the counter sales will be 425 mesh or so. Ive been using 10,000 and above mesh for parts with, I believe, great results right out of the mould. If you can get ahold of a very fine mesh (the auction site is a start) aluminum powder, that is a great base for any silver part. Using graphite powder cut in with that will darken the color tone as needed up to your desired look. For browns and black, reds, yellows... I use an ultra fine mesh oxide powder, some iron, some steel, some aluminum... which blend well together. I do not mix powders into the casting material, just brush powders into the mould. For a better surface shine the master part would need to be shiny itself when moulding. This can be done with gloss clear coat, or melted Vaseline then applied and remelted over the master part before silicone, or a shiny mould release. It all depends on the gloss surface desired for the final part. The ultra fine mesh metal powder will buff onto the silicone with a make up brush and a little goes a long way.
Ive attempted to explain the method a few times here on the board, even over the phone, shown people face to face, and they seemed to note have much luck repeating the process, so again, when you find something that works for you thats the way to go.

Also I have to add I do not use cheap casting resin but a high impact plastic. Hobby resin is usually full of bits of filler, air bubbles, and has a wave type surface finish to it when cured. As an example, below is a photo of a sheriff star badge that is less than seven grams of material yet the part is rigid and durable. Even after 12 years those parts have not warped, bent, leached, snapped, and look as good as the day they were made even after various usage on projects. Hobby resin, I dont believe they would have made it out of the mould.

These are all parts directly from moulds, as is. Very basic.
IMG_57271.jpg

A Sector 7 badge and how those castings were done.
IMG_6403_edit.jpg

and ive posted this before, when you get good with the materials. These held up during lots of stunt filming and used on a couple projects. Never needed a touch up or repaint. And of course these are directly from the mould. The original knife on the bottom, two castings above.
DSC043211.jpg
 

NakedMoleRat

Master Member
a lot of good info here. Through trial and error, in the end whatever method works for you is the method that works best.

As prior mentioned black casting material vs white casting material will yield color differences on the final part. With metal powders, the finer the mesh the finer the metal particle the finer the metallic surface finish.... Most hobby and over the counter sales will be 425 mesh or so. Ive been using 10,000 and above mesh for parts with, I believe, great results right out of the mould. If you can get ahold of a very fine mesh (the auction site is a start) aluminum powder, that is a great base for any silver part. Using graphite powder cut in with that will darken the color tone as needed up to your desired look. For browns and black, reds, yellows... I use an ultra fine mesh oxide powder, some iron, some steel, some aluminum... which blend well together. I do not mix powders into the casting material, just brush powders into the mould. For a better surface shine the master part would need to be shiny itself when moulding. This can be done with gloss clear coat, or melted Vaseline then applied and remelted over the master part before silicone, or a shiny mould release. It all depends on the gloss surface desired for the final part. The ultra fine mesh metal powder will buff onto the silicone with a make up brush and a little goes a long way.
Ive attempted to explain the method a few times here on the board, even over the phone, shown people face to face, and they seemed to note have much luck repeating the process, so again, when you find something that works for you thats the way to go.

Also I have to add I do not use cheap casting resin but a high impact plastic. Hobby resin is usually full of bits of filler, air bubbles, and has a wave type surface finish to it when cured. As an example, below is a photo of a sheriff star badge that is less than seven grams of material yet the part is rigid and durable. Even after 12 years those parts have not warped, bent, leached, snapped, and look as good as the day they were made even after various usage on projects. Hobby resin, I dont believe they would have made it out of the mould.

These are all parts directly from moulds, as is. Very basic.
View attachment 1357999

A Sector 7 badge and how those castings were done.
View attachment 1358001

and ive posted this before, when you get good with the materials. These held up during lots of stunt filming and used on a couple projects. Never needed a touch up or repaint. And of course these are directly from the mould. The original knife on the bottom, two castings above.
View attachment 1358004
WOW!

Thanks for that info. I may try to go more professionally in the future and this info is great! For my coins, which are just for my gaming use, I used clear resin with the powder mixed in. I dusted the molds first, used a 350 mesh, and then buffed with 0000 steel wool. I did notice that aluminum buffed out considerably more easily and quickly than copper or brass did.
 

robstyle

Master Member
you can also try a very basic and cheap casting material for coins, Crayola Crayons. The silver ones in particular make great coins with a little silver dusted into the mould.
 

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