Metal fillers for resin??

Johnnycrash · Post by **Johnnycrash** » Fri Jan 09, 2009 12:25 am

Hey all you other resin casters out there,

I need your help/advice/experiences. Not even sure this is the right place, but here goes...

I have a project that will require adding metal fillers to my resin mix. Metals such as bronze, silver (silver nickle), brass, copper, and zinc. And maybe a few others, yet to be determined.

I have NEVER added metals to resins. A few drops of pigment, but thats it.

I have done a few quick searches, and found a few places that carry such filler things. But I am looking for other's true life experiences with using metals.

What was the finish like??
Could you polish it to make it all shiny and new looking??
How thick did it make your mixture??
How much (percent wise) did you have to add to get a metal looking cast??
How strong was the casting afterwards??
Can I use things like metal shavings/dust/powder from milling (iron fillings??) and things like that??
Will it hold the same detail as just resin??

Help!!

Antenociti · Post by **Antenociti** » Fri Jan 09, 2009 8:15 pm

never done it personally but we own some metal-filled masters that were made for us a few years back.

they are heavier and stronger than normal resin, but slightly brittle, but generally much harder wearing for production of production moulds from the metal-filled master. They hold the same detail as the resin would normally.

modelbaseguy · Post by **modelbaseguy** » Fri Jan 09, 2009 10:46 pm

John, I have done my share of resin casting and I have added quite a few things to the mix for various reasons but never metal. One resin company I know offers metal powders additives that can be mixed in the liquid resin or dusted on the mold before pouring for a coated effect. While I have never used these products I can tell you that you must be very careful as to what you add into a chemical mix like resin. I added a silica powder to some resin once and all was well until the resin began to heat up. Ever built a baking soda and vinegar volcano? Imagine that the harmless "lava" hardening into swiss resin and that is what I was chipping off of my workbench and basement floor for a couple of hours.

Metal shavings? Not sure that would be such a great idea as they are sure to settle in the mold too quick and leave a rough surface. You could use fine ground metal like aluminum, brass, bronze or nickle but avoid anything with iron. The metal will have to be really fine and filtered for size. While it is an additional cost, I would stick with the powders that are intended for mixing with resin. I have seen finished pieces and they look like cast metal. They can be polished and machined without issue but once again I have not had first hand experience in working with the powders.

You might want to ask for some samples from Smooth-On. Good luck with whatever you decide.

Stu Pidasso · Post by **Stu Pidasso** » Fri Jan 09, 2009 11:37 pm

modelbaseguy wrote: I added a silica powder to some resin once and all was well until the resin began to heat up. Ever built a baking soda and vinegar volcano? Imagine that the harmless "lava" hardening into swiss resin and that is what I was chipping off of my workbench and basement floor for a couple of hours.

I'm sorry for your frustration, but I found that quite hilarious. Just an observation from a fellow caster who's done his share of boo-boos...

DasPhule · Post by **DasPhule** » Sat Jan 10, 2009 10:19 am

Smooth On makes metallic fillers that look great when used. I've used some of them and they always turn out great, but you have to use the right resin and enough of the filler for it to look right. I'm sure you could probably polish it once set up, but for it to make a difference you'd have to add a lot of the powder, and it aint cheap. Check it out at their site.

Erin
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Johnnycrash · Post by **Johnnycrash** » Sat Jan 10, 2009 11:17 am

Thanks for the replies guys. Yeah, I knew it was going to be expensive, but the objects are very small. That's why I was worried about the detail. They will run about 2 to 3cc total. From what I have read at Smooth-On's site, I need to add about 50% fillerto get a good look and feel. So, in my case, that's only 1-1.5cc per casting. I'll get some milage out of a 5lbs tub of filler. Unless I screw it up badly, and I'm sure I will the first couple times. If this works out, it will open up a whole new avenue for me and MMI. I'm really looking forward to this project(s). I have some ideas for you sci-fi guys too. And SSM might find it interesting for the store. But more on that, maybe, once I get this project rolling along nicely.

Thanks guys. Keep it coming though, please. The more info the better.

Anyone tried good old sand?? Or is that too similiar the the silica?? I guess all sand isn't silica, so... Time to find some sand!!

Post by **TER-OR** » Sat Jan 10, 2009 11:40 am

The metallic powders I've seen have been used as mold-release dust and the resin will have a coating of metal when done. It did not permeate the resin.

Johnnycrash · Post by **Johnnycrash** » Sat Jan 10, 2009 11:50 am

TER-OR wrote:The metallic powders I've seen have been used as mold-release dust and the resin will have a coating of metal when done. It did not permeate the resin.

But couldn't that cause all sorts of issues?? If the resin, when poured into the would could "wash" the powder off the mold. The powder could be permiated by the resin, giving "bald" spots on the surface. Or am I missing something about how it's done??

Post by **TER-OR** » Sat Jan 10, 2009 1:52 pm

You'll have to check with Sparky. The coverage is pretty good, though. It does need to be sealed, or it tends to rub off. A Future coat does the job fine.

DX-SFX · Post by **DX-SFX** » Sat Jan 10, 2009 6:41 pm

We mix aluminium powder into polyester (fibreglass) laminating resin all the time. Normally polyester isn't ideal for casting but mixed with aluminium powder in a ratio of roughly one part resin to three parts powder gives a mix that can be brushed on like a gel coat or cast without excessive shrinkage or bubble entrapment. It looks a dull grey colour but once set, you can buff it with metal polish and it's almost indistinguishable from metal. Depending on the metal being used, you might find the ratio needs adjusting but simply put as much as you can in before you feel the mix start to unduly thicken. It's surprising how much will go in. You can also use epoxy resin with virtually identical results although epoxy doesn't give up air bubbles quite as easily.

DasPhule · Post by **DasPhule** » Sun Jan 11, 2009 1:02 pm

As for sand, again SmoothOn has a filler like that. The stuff I used when doing the big Ferengi Pods is called Ure-Fil 3. Looks like coarse white sand. 5 Gallon bucket is pretty cheap, too. It thickens the resin as you add it (not too too bad) obviously, but it didn't seem to stop it from setting up right or anything. It definitely saves you resin when you use it, but the parts will be slightly more brittle.

I used their Cast Magic Silver Bullet and it works great for metallic sheens, but it's kinda expensive and you have to use a lot of it to get truly metallic sheens.

Good luck!

Erin
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