How to Spray Chrome a 3D Print With Cosmichrome

by goldtouchinc

16K346

Intro: How to Spray Chrome a 3D Print With Cosmichrome

Cosmichrome is ideal for applying simulated gold, chrome, copper and nickel finishes to 3D prints. The coating is applied in a paint booth. Most 3D model shops already have paint facilities so Cosmichrome is a logical addition to 3D part production. In this example the skulls are SLAs. I believe they were made in an Objet brand printer but I am not certain.

STEP 1: Cleaning and Priming

I cleaned off the waxy residue from the setup material with a toothbrush and alcohol. I mounted the prints to dowels using hot glue so I could hold them without touching the paints. Then I applied an Epoxy primer because I wasn’t certain how well I had removed the residue. Unfortunately the primer never hardened so I removed it with lacquer thinner and got fresh epoxy primer from the local paint store. I then let the primed part dry over night at room temperature.

STEP 2: Applying Cosmichrome Base Coat

Then I applied Cosmichrome base coat. I applied three layers to be sure I got good coverage down in the low spots in all the detail on the model. I let the base coat dry over night at room temperature. The base coat can also be baked to speed up the drying process but on delicate 3D prints heat can distort the shape of the part so room temperature drying is the safest choice.

After the base coat was completely dried I flame (plasma) treated the base coat then proceeded to the plating process.

STEP 3: Spraying the Cosmichrome Finish


After the flame treatment I primed up my Cosmichrome spraying system. This involved merely hooking it up to clean compressed air and priming all the solutions through the e_Gun Select™. Then I started the plating process that you can watch here. We use distilled water for rinsing in between each step. After plating it I put it in front of a fan for about twenty minutes while I mixed up the top coat.

STEP 4: Topcoat

The Cosmichrome top coat is applied like the base coat. Just use two medium wet coats. Apply the topcoat so it is so transparent. It virtually disappears on the chrome surface. I use a Sata Minijet with a 1.2 mm tip.

Cosmichrome top coat bonds the three layers together and is guaranteed not to discolor or turn yellow from UV etc. It's the only spray chrome that has such a guarantee. Cosmichrome is used in design and model shops in places like General Motors and Whirlpool for example. General Motors has been using Cosmichrome for about ten years.

You can also tint the finish with one of Cosmichrome's transparent tints to make all sorts of chrome colors. You should let the top coat dry overnight before it will take light handling. You can also bake it at a low temperature to speed up the curing if you like Just don't go above 100ºF on 3D printed parts.

Thanks for checking out my first Instructable. I will be posting how to chrome wood for my next one.

http://goldtouchinc.com

5 Comments

nicamarvin 8 years ago

This is awesome, but the machines are profecional grade and out of the budget of 99% of the people that visit this site, I will be doing a How To for very small pieces like 3D printed parts, on a shoe string budget

SabbirS 9 years ago

sweet instructable! have you tried this technique on ABS / PLA?

goldtouchinc 9 years ago

I have never tried PLA that I know of. ABS is not problem. If the material can accept a solvent based paint it lends itself to spray painting it can almost certainly be coated with Cosmichrome. There are even work arounds using water based primer on materials that are not solvent proof. Solvent based primers have to be catalyzed or they will melt into the base coat and contaminate it Urethane, epoxy and polyester 2k primers are frequently used to level parts before the base coat is applied. I have used a PPG water based primer a few times and it worked fine but it couldn't be wet sanded. Priming though is entirely optional. Mostly people apply base coat right onto smooth plastics. Polypropylene is hard for any paint to stick to so it should be treated with adhesion promoter and primed with a solvent based 2k primer. Even super glue doesn't stick to it.

SabbirS 9 years ago

wow. thanks for the detailed reponse!