Prepping & painting 3D printed parts

Model Railroader General Discussion (Model Railroader)
1

Received my 1st 3D printed detail items in F.U.D. (frosted ultra detail) from Shapeways. There’s much info out there about prepping & painting items printed in this material, some conflicting. Like bathing items in sunlight or UV light to insure complete curing. Then minutes to hours long immersion in iso-alcohol or denatured alcohol, mineral spirits, Bestine, white-wall tire cleaner or Simple Green.

There’s also cautions about using enamel paints, lacquers & other solvent based paints. Last thing I want to do is melt or distort these expensive finely detailed little beauties.

Hoping for some forum advice and tips about prepping & painting 3D printed FUD material, and also hoping to use solvent based paints.

Thanks and regards, Peter

2

Shapeways has their own forum with a thread that discusses painting FUD Is that where the conflicting info is?

Evidently oil is part of the finishing process so you need a sovlent to remove that. The examples I saw were all painted with acrylics.

3

Thanks for the reply BigDaddy,

Conflicting info about needing to cure the parts with UV light and what cleaners and paints to use on FUD parts is all over the internet, including Shapeways forums.

regards, Peter

4

Their parts aren’t exactly dirt cheap. Shapeways should provide better guidance. The high frequency posters on Shapeways would have more credibility than some random post out in the Internet.

Plastic, by its very nature is not absorbant so the need to soak for hour in a solvent sounds like overkill. Best of luck.

5

Excellent question, Peter!

One of the most debated, and occasionally difficult, topics related to 3D printed acrylic models (including FUD and FXD from Shapeways) is the best method of removing the wax residue from the temporary supports used in the Polyjet 3D printers.

Shapeways does a good job of cleaning models, but there is normally a bit of oily deposit and sometimes a bit of a crust of hard white wax left on surfaces where support was needed. Currently, they melt the wax off in warm mineral oil followed by some hand cleaning, and the parts must be further cleaned prior to painting.

I have long recommended the use of Simple Green, a non- toxic, biodegradable cleaner for this job. I recommend a 30 minute soak, followed by a light scrubbing with a soft toothbrush and a rinse in a bowl of warm, clean water. Following this, to ensure the surface is totally oil- free and ready to paint, I dip parts in isopropyl alcohol before air drying. They are then ready to paint.

The product’s MSDS sheet can be seen here:

http://simplegreen.com/pdfs/MSDS_EN-CA_SimpleGreenAllPurposeCleaner.pdf

At $5.99 CDN for a 650 ml spray bottle, and readily available at Canadian Tire and other retailers, it is easy to obtain.

I suggest you forget the nasty chemicals, and use Simple Green! I don’t normally endorse products, but this is an exception I&

6

In 2015, I bought an HOn30 boxcab from Shapeways, and posted how I processed it from cleaning to driver install:

http://cs.trains.com/mrr/f/88/t/244840.aspx

7

Thanks Steve, I just happen to have a jug of Simple Green on hand.

That is exciting news about possible ready-to-paint FUD.

Do you feel it prudent to expose Shapeways FUD parts to UV light before cleaning & painting to insure resins are fully cured? And if so would sunlight do?

Thanks again and regards, Peter

Thanks for the link George, good stuff.

8

http://cs.trains.com/mrr/f/88/t/244840.aspx

Clickable link to George’s project.

Dave

9

I’ve never found any need to do this UV exposure routine.

It can’t hurt though, as long as you aren’t setting it in the sun (or lamps) where temperatures get to the point where the acrylic can soften, and don’t leave the model out there long enough for the parts to begin yellowing. I don’t believe it adds any value, however.

If you are watching the Shapeways forum, you may see some users experiencing “powder on the surface” of some FUD or FXD models. I have never seen this after hundreds of models, so I believe it is either from inadequate cleaning- perhaps oil crystalizing over time or wax particles.

Notably, several of the UV post- curing advocates claim to have powder appearing. Perhaps their feeling that post-curing is needed is actually a reaction to a poorly cleaned model.

Inidentally, if a model arrives warped, this is from the cleaning mineral oil being a bit too hot at the factory. The part can easily be straightened by holding it in very warm water- about the temperature where it feels hot but you can still hold it without discomfort- for a minute, until it softens slightly. You can then, after making sure it has softened, gently straighten it (just like a resin part). An electric blow hair dryer can be used for this as well.

Have fun with your models!

Steve

[quote user=“HO-Velo”]

Steve Hunter
Simple Green

Thanks Steve, I just happen to have a jug of Simple Green on hand.

That is exciting news about possible ready-to-paint FUD.

Do you feel it prudent to expose Shapeways FUD parts to UV light before cleaning & painting to insure resins are fully cured? And if so would sunlight do?

Thanks again and regards, Peter

10

I’ve had some FUD parts from Shapeways as well. They had a ‘powdery’ finish, which came off when I washed them in water with some dishwashing detergent mixed in.

Given that I’m in Australia, the parts spend 2-3 weeks in shipment after printing. As I’ve had this powdery finish on all parts I’ve received, it would imply that it’s something that’s time-based. At least it’s easy to get rid of.

FWIW, I don’t UV-set them either - I didn’t even realise that was a thing. I just clean, assemble and paint them.

11

The powder that may be on parts as received from the factory is normal. That is just wax residue that was loosened during cleaning but settled on the surface.

The discussion on Shapeways’ forum is something that appears over time after cleaning. While the jury is out, only some users encounter this and it definitely appears to be linked to inadequate cleaning or use of damaging solvents.

Steve Hunter

12

Steve, Likely overkill, but sun bathed my FUD parts for a few hours. Checked and turned them every half hour or so and didn’t allow them to get too hot. After removing the items from the sunlight I placed them on a paper towel. About an hour later was surpised at how much “wax” had sweated out of the little items onto the paper towel, I guess the warming from the sunlight caused this, but maybe a good thing? Next up will be a prolonged bath in Simple Green after my order of Tamiya acrylics arrive.

Thanks & regards, Peter

13

Update: The 3D printed FUD gas pumps are done & have been sitting for a couple weeks. But yesterday it was noticed that one had leached a small amount of what I assume is printing wax out the unpainted bottom leaving a small stain on the pump island surface.

Maybe soaking the pumps in Simple Green for three hours and the two thorough scrubbings with a small brush wasn’t enough to remove all the “wax”. The bottoms of the pumps are hollow, but cleaned them out with a small bottle brush. Maybe the sun bath prior to cleaning contributed to the leaching, or maybe a stronger cleaner should have been used? I don’t know that the leaching isn’t uncured resin?

The pieces were given a base coat of Tamiya spray-bomb white primer after cleaning & drying. The top coat of air brushed Tamiya acrylic paint cured just fine and showing no signs of flaking. Still, I’m hoping all the detail work doesn’t turn out to be in vain.

Much knowledge was gained from this little project. A bonus was being prompted to finally give serious effort to airbrushing with acrylic paint. Even went so far as to put my long of tooth single-action bottom feeder aside & purchase a gravity feed dual action airbrush. Old dogs can learn new tricks!

Thanks to all & regards, Peter

14

Guys, some very interesting developments are coming from Shapeways soon, starting with a new FUD/ FXD pricing structure that will mean serious reductions on many models (and, inevitably, higher costs on a minority).

Stay tuned, but from my perspective it is a very good thing. Others, particularly those who don’t use sprues, might disagree… my design methodology fits the new environment well, some others, not so much.

Following on this change’s heels, probably within a couple of months, we’ll see factory cleaned Ready to Paint FUD and FXD. Having been lucky enough to participate in testing for this, I know it will be a good thing.

Third, some time in the next few months, designers will be given the ability to set the print orientation. This may drive some prices, but it directly affects quality and in the right hands will yield spectacular results.

It’s a very exciting time, guys. We’ve been waiting for these changes a very long time. Keep watching as they roll out the changes.

Steve Hunter