Cold Metal Spraying - REAL metal coating, anyone?

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bn86

New Member
Has anyone managed to DIY this?

If you don’t know, this is a proper metal coating (not paint) made with 95% metal powder + a binder*, referred to as “sprayable liquid metal”, and “cold-spray composite decorative metal coating”. It can make any boring material look and feel like solid metal - iron, bronze, copper, brass, aluminium, gold, whatever. It’s cold to the touch, waterproof, really tough, and even rusts/oxidises and polishes like metal. Kinda like “cold casting”, but sprayed with an HVLP gun instead.

Game changer, right? Except I never see anyone doing it. Apart from interior designers and architects, and big prop shops like Weta Workshop. But what about us? We need this!

It's offered by various different companies as a coating service, who often also sell training courses to allow you to become an authorised applicator, but they’re all suspiciously vague about what the secret “binder” actually is. One big supplier offers three types: “solvent-based binder”, “water-based binder” and “flexible water-based binder.” I suspect one of the options is epoxy resin, but I’d really like to avoid spraying that. The most interesting option I've seen is the flexible binder as it would be perfect for the kind of things we do. A few of the companies I found referred to a polymer binder and a catalyst, if that gives any clues?

*Does anyone know what that magic ingredient might be?
 

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joberg

Master Member
As you said, it would be a game changer...saying that, maybe the pros here on the RPF could shed lights on the product:unsure:
 

bn86

New Member
Ok I have made some decent progress:

I found a pretty revealing trailer for a training course showing how it's all done, except unlike the other courses (who want you to buy their own secret ingredients in vaguely-labelled cans) this guy doesn't sell supplies, seems totally open about the ingredients he uses, and where to get them locally - which I appreciate. While it looks like a pretty good online course, I'm not ready to spend $480 / £350 right now. I couldn't believe my eyes when I noticed the brief shot at 48 seconds showing a bunch of bottles on the table in front of him. This is what I've been trying to find for months! I've managed to track them all down:

From left to right:

Evo-Stik General Purpose PVA adhesive
"highly effective primer, bonding agent, dustproofer and may also be used as an adhesive"

SikaLatex SBR Primer and Admixture
"latex-based, water resistant bonding agent & admixture... improved toughness and flexibility"
- could this be the flexible binder Weta Workshop uses?

Caparol Binder
"transparent synthetic resin dispersion, ideal for priming canvas and other supports, for glazes and for making colours"

Jackson's Acrylic Extra Heavy Gel Gloss Medium
"extra heavy acrylic gel of extremely high viscosity. Dries translucent and glossy."

These look like UK products. The first two seem to be used in home improvement for cement and drywall, and I think the second two are used by artists for working with canvas. Interestingly they are presented in order of price - I wonder what the differences are in practise?

I hope this helps somebody.

I managed to get hold of some "Bostik Cementone - primer, admixture bonding agent and dustproofer" which seems pretty similar to some of the above. I will mix with metal powder into a thick paintable consistency and report back.
 

TazMan2000

Master Member
Hmm. Interesting product. But obviously with a training course there is specialized equipment that would be needed, much like that mirror chrome stuff. I'll wait until something similar comes out in a can that I can buy in my local hardware store.

TazMan2000
 

bn86

New Member
Update: As promised, I've now experimented with 100% metal powder (bronze and iron) mixed with the above primer/admixture.

I mixed to a thick brushable consistency in a plastic pot, globbed it straight on by brush and it pretty much self-levelled. I didn't do any surface preparation for this test. Here are the results on some EVA foam, injection moulded plastic, and wood. It goes shiny after you give it a quick sand.

Bronze EVA Foam.gif

Iron Plastic.gif

Bronze Wood.gif


I'm pretty excited by the results so far, but need to do more testing. Since it's real metal, I want to try making it rust now.

Dries quick. Cleanup is just water, which is nice. No epoxy here, all water-based and non-toxic.

I'd still love to hear from anyone with any experience, as I'm just making this up as I go along.
 

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bn86

New Member
No way TazMan, it's pretty strong.

Torture tests:

Steel brush.gif

Plastic brushing.gif

I tried to destroy it with a stiff steel brush, but it just went shinier.


Hammer time.gif

Hammering the bronze on the wood did nothing. Maybe because it was quite a thick coating and also this stuff sticks to wood really well.


Torture test.gif

Hammering the iron-coated plastic eventually split and could peel off. Then again, I did nothing to help the glue stick. Maybe a rough sanding first would help.

Still, pretty tough!
 

TazMan2000

Master Member
Like you said, it's a game changer. Is it hard to purchase or find metal powders? I couldn't even begin to think where this stuff can be purchased.

TazMan2000
 

JPH

Sr Member
I kinda feel like this is an infomercial.

There are flexible epoxies that you can add metal powder.

It looks neat. It looks convenient.

Doesn't really seem to *behave* like aluminum or steel.

Wait... WHAT?! If I order now, I can get a SECOND KIT?!?!
Just pay shipping and handling?!?!
 

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bn86

New Member
Haha I am pretty excited about it. Just need to figure out how to spray it. I feel like epoxy might be tougher, but this water-based stuff is much nicer to work with.
 

bn86

New Member
Like you said, it's a game changer. Is it hard to purchase or find metal powders? I couldn't even begin to think where this stuff can be purchased.

TazMan2000

Places that sell resin or casting supplies often seem to sell metal powders, mostly used for “cold casting“, which there are loads of good videos about. That’s great, but it only works if you have a mould. My ultimate goal here is to be able to spray any object, big or small, and have it basically turn into metal, without the need for a mould.
 

ID10T

Sr Member
I work with metal powders (and ceramic and carbide) all the time. I can easily whip something up to brush on.

I would like a finer powder I could disperse in a catalyzed acrylic urethane for spraying onto printed weapons.

Maybe tomorrow I’ll mix up some toxic brew… my powder is a bit coarse so it may not look as good…
 

ID10T

Sr Member
Edit- finer powders (especially iron and aluminum) are difficult to get because they are used to make explosives.
 

bn86

New Member
I work with metal powders (and ceramic and carbide) all the time. I can easily whip something up to brush on.

I would like a finer powder I could disperse in a catalyzed acrylic urethane for spraying onto printed weapons.

Maybe tomorrow I’ll mix up some toxic brew… my powder is a bit coarse so it may not look as good…

That would be amazing. Any insights you can offer would be really appreciated.

Catalyzed acrylic urethane, you say? Do you reckon this might be what these “liquid metal“ companies are using?

How fine are we talking? The aluminium, iron and bronze powders I’ve got are like flour - I can’t feel any grit between my fingers.
 

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ID10T

Sr Member
If you can get aluminum and iron that fine, you can make thermite! Are you in the states?!?

“Two part” automotive clear coat is basically what I described. Many now are more like an epoxy to avoid the solvents but all the two part clears act the same- they turn to rock in the gun if you don’t clean it out because they chemically cure and don’t rely on solvent evaporation.
 

Krats

Sr Member
RPF PREMIUM MEMBER
I would have a lot of use for this on printed parts.
OP, where did you find the metal powders
Metal powder is available through specialist casting material suppliers, however you can also order it through Amazon. Search "metal powder cold casting" and you should get a load of options.
 

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