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.
