Coldcasting

Mados

Mados

Well-Known Member
RPF PREMIUM MEMBER
I'm wanting to cast a prop with a metal look, and don't really want to paint it to get the results I want. I had some Smoothcast 325 sitting in storage, so I got some aluminum powder and tried some castings today. It doesn't really look like metal, maybe I'm putting too much powder into it? It just looks grey. Before continuing does anyone have advice? I'd appreciate it, I'm a noob.:lol
 
You'll have to use fine sandpaper of 400 grit and above to get the metal sheen to come out. You can also use 0000 steel wool.

Basically you have to polish the surface similar to cast metals.
 
Thanks for the tips. I did think of trying rub n buff. I'll try polishing and may post some pics tomorrow, but am dead tired now. About how much powder should I use? I'm using a rough measurement of a teaspoon of powder per 2oz of plastic. Should it just be a plain gray color when it comes out of the mold? Just looks like plain grey plastic.
 
I think it's 1 to 1 isn't it? I had heard youcan dust your moulds as well? The few items I have done steel wool brings out an awesome sheen.

Here's a cool idea...say for instance you were casting up a resin Medallion to the staff of ra....tint your resin brown and add your brass powder. When you buff it the indentations will be picked out in brown. It looks cool:)

Regards
TAZ
 
This is the prop I'm casting, the original is machined aluminum.
IMG_0397.jpg


So half powder, half plastic?:confused
 
Understand that even real metal doesn't come out of a mold looking right. Cast iron, steel, whatever needs a polish or it just looks like slag.
 
does the resin you are using cure white without filler? to get the best results from cold casting you really need to use a resin that is transulent when cured, it doesnt have to be crystal clear, i know smooth on do a clear casting resin tht cures to a light amber colour tho i cant think of it off the top of my head.

the white resins will only yeild a grayish cast and polish will help but its worlds apart from using a clear resin. also use as much alu powder as the resin will take before its unpourable.
 
For the Jango Fett armor the closest cast I've ever seen is for 100g of resin, 125g - 130g of ali powder.
 
I have found that using the brush on powder in the mold as well as mixing it in the 325 gives the best results. I think the powder sometimes settles in the 325 so its not on top the surface good enough so the brush on type helps with that. Good luck.
 
Got to dust the molds with the AL powder first... Has to be a fine grain powder too. And for heavans sake wear a respirator...aluminum dust will 'F' you up BAD!


M
 
Thanks for all the tips guys, I knew this place would have awesome advice. I'll let you know how it comes out! I'm being very careful not to make any dust with the powder, its a 425 mesh filtered powder. I do need to invest in a respirator.

I think you are right about the settling smick, the tops of the large pieces seem to not have as big a concentration of the aluminum mix.
 
I use a clear casting resin with alumunum powder mixed in. It comes from the mold grey, but as said above. Sanding with fine paper, and polishing make all the difference.

twokpartsik1.jpg
 
These pieces are machined aluminium, aren't they? :eek What % do you use for cold casting?

It looks awesome :eek
 
Thats the effect I'm going for! How much powder do you put in there in relation to the resin?
 
I just carefully mix in as much as I can in small amounts. The Clear resin I use takes a good 12 hours to Cure, and I use a pressure pot to keep bubbles to a minimum.
 
You must log in or register to reply here.
Back
Top