Sunday, November 29, 2015

Post Production of 3D Prints #1

If you've stopped by to see what I am up to recently, you know that I wanted to try something completely new with the Alki Point project; making 3D printed items for the majority of the interior design. I have most of them in my hands, but now what do I do?

I needed to decide what I wanted the finishes to look like, and then do a little execution research. What type of adhesive should I use to adhere them to my wooden dollhouse walls? How about gluing it to one another? What kind of paint should I use? Can they be sanded? Primed? Filled? Do they melt like foam does if spray painted?

Several hours of research later, I came away from the Shapeways Forum on Post Production Techniques like most everything else I research. There is really no absolute. Try what works for you and then post your experience to the collective record in the forum. Okay, so I am going to experiment a little, and hope I don't ruin anything in the process.

I should point out that there are many, many different types of material available for you to have items printed in. Plastics, metals, precious metals, sandstone, ceramic, acrylic etc. I have only had them printed in three different materials so far:

~White, Strong & Flexible - Flexible, slightly gritty surface, bright white.
~White, Strong & Flexible Polished - Smoother finish, slightly glossy, bright white.
~Metallic Plastic - Grey with metallic specks, stiff and brittle.

So, until I am able to purchase things in other print materials, this post will pertain only to White, Strong & Flexible and White, Strong & Flexible Polished.

The forums pretty universally recommended that you wash all WS&F pieces thoroughly with soap and water. I filled up a Rubbermaid tray with hot, dish soapy water and used a washcloth to scrub each piece. After a good rinsing, I laid them on paper towels to dry.

The WS&F material is actually Nylon 12. It is pretty porous when not polished, so sealing it with a dip of Future wax or priming before painting was also recommended. I wanted to see how porous it would be un-primed as part of the experimenting.

I didn't have to buy any paint or sealer because I already had these on hand. The Krylon is supposed to be white paint and primer in one. The chrome metallic does not say to use on plastic. It says "for use on wood, metal and more". I hoped the "more" meant Nylon 12. I probably really need to varnish the metallic finish afterwords, so I'll give the gloss spray Mod Podge a try.  

The white paint took four light coats to reach this point. I just coated each piece lightly, letting each coat dry for about 45 minutes in between. One of the tile walls was printed in WS&F Polished. I noticed a more uniform coat of paint, and it seemed to soak into the nylon less. My conclusion is to pay the extra few cents when possible, and have the piece polished. Feels and looks smoother, as well.

The metallic paint is certainly more apt to soak in. I painted at least five coats, also letting them dry thoroughly in between. When I would go out to the garage to check on them, you could see the nylon white coming through in some spots. Notice the piece of wood I am using - the chrome looks promising!

The high temperature today was 39 degrees, so it is cold, but the humidity is low. I had a space heater in the insulated garage, so it was probably somewhere in the 60's in the airspace around the paint. I am going to let all of the pieces dry overnight, then I'll varnish the chrome pieces.

My next post on Post Production of 3D Prints will be about what I find attempting to glue the shower tile walls to the wood bathroom walls.

Until then, I am going put on some bigfoot podcasts, measure the bathroom and kitchen and start making the cabinets!

If you are planning to buy and finish any 3D printed miniatures in the future, here are a couple of helpful tutorials from Shapeways on glues and paint:

The code for 20% Off + Free Shipping this weekend is BFDEALS.

After drying overnight, the chrome painted parts were dry and looking promising. The bathroom faucet seemed to have some debris or badly painted bumps, so I sanded it lightly with 0000 steel wool. The sanding took a good deal of the sheen off, and left it looking like it had received a coat of watered down black paint. I guess if you are going for the well used look, this might be just fine. Sorry I forgot to take that photo!

These are test pieces, so I decided to go all of the way with them just to see how good or bad the results would be. I added the sinks and toilet to the metallic pieces ans sprayed them with the Mod Podge gloss.

I DO NOT recommend this! It seemed to actually dull and crackle the chrome finish, and now the sinks and toilet look like they have debris in the finish. :0( Not sure if it is just the Mod Podge, or the reaction that the chrome paint would have with any aerosol varnish.

Back to the drawing board... With the new pieces, I am going to try wet sanding, priming, white spray acrylic for the sinks and toilet, and the chrome again for the fixtures. Maybe I'll try Triple Thick to add the shine. More updates to come...


  1. I'm hoping the chrome works well for you, it looks great so far. Looking forward to your adventures with adhesives.

  2. Oh Keli me too! I am impatient sometimes, and last night got my finger stuck on one of them, In the interest of science, I have one more set of these to try in case I've really messed this batch up! For those guys, I will definitely primer them first! Utter failure or triumphant victory, I'll post about it!

  3. I use Testors model paint on my 3d printed items. Gloss silver or aluminum. I usually need 3 coats to look good. It's oil based so you can't seal it, but don't have to since its oil based.

    Maybe it crackled because the mod podge is water based and the silver spray was oil based. I'm pretty sure I used thinner to clean after my silver Rustoleum which makes it oil based

    Try a Testors model paint in a clear gloss for the sheen you want. It's at hobby stores, most art stores and Michael's.

    1. Thanks so much for your knowledge, Kat! It is so funny that you recommend Testors! I had a primer and gloss white in my Amazon cart. Then I read on the Shapeways forum that someone had trouble with Tamiya and WS&F Polished. They said after about 5 days the combined chemicals were causing some reaction. I chickened out on model paint and just went with what I had on hand.I will definitely get the Testors now!

      You are probably right about the metallic paint being oil and the Mod Podge being water based. The metallic really looked good enough until I messed them up! I think I could have done a better sanding job, then sprayed on lighter coats.

      Thanks again for the advice! I will try it and report back!

  4. And I'm totally gonna hit up your Shapeways store on their next free shipping event. Love it!

  5. I had some great enamel metallic spray paint that gave a really good finish to polished WAS but can't get it locally any more. I have some 'regular' metallic spray and I found I needed a primer for it to take well without too many coats. It also helps if you want a gloss finish to your white goods, and to use a gloss paint rather than a gloss finish (iykwim )

    1. Oh good tips, Alice! What kind of primer do you use?
      I am having trouble just looking at spray paint labels. Some of them don't say if they are oil based, acrylic, enamel, for plastic etc... Who knew this would be so troublesome!