Thread started by uhrwerk
Ben M@Rick TaylorRick, a question about Vargas models, how do you prep the plastic prior to assembly and paint?
11 August 2021, 00:20
Rick TaylorBen,
This is 3D printed resin, so the prep is pretty simple. But as it is a new technology, there is a learning curve. This is my 12th 3D printed kit, so I've learned by trial and error.
1. Carefully scrub parts with a soft toothbrush in warm water and dish soap. Rinse in warm water.
If the water is too hot it will cause thin parts to warp.
2. Repeat step 1. There is a lot of junk that comes off the parts. Blow dry with your airbrush
3. If any parts look like they have a shiny thick coating, rub it off with a cotton swab and 91% isopropyl alcohol.
4. If any of the parts are soft or sticky. Put the parts out in the sun for a few minutes to allow the sunlight to finish the UV cure. Don't leave the parts in the sun for too long - they will get extremely brittle.
5. Prime the parts while they are still on the supports with a good sandable primer. I've experimented with a bunch of different primers. I have settled upon Mr Surfacer 1000 rattle can as my preferred product for this task. My second choice is inexpensive rattle can sandable automotive primer. With a well printed kit, priming the parts prior to assembly will handle the vast majority of the striations
6. Remove the parts from the support structures (sprue equivalent) and file/sand off the numbs and striations. It's best NOT to use your good GodHand nippers to remove the supports as the resin is harder than styrene.
7. At this point you are ready to assemble. The fit is usually good as the kits are CAD designed. As opposed to cast resin, you don't have any pour plugs, air bubbles, pin holes, or short shots to deal with. Scrape the primer off the gluing surfaces. Dry fit. and glue with CA or 5 minute epoxy.
8. After assembly, I prime again. This time, I use Mr Surfacer 1500 black as it will highlight any missed striations.
I hope this helps.
Rick
11 August 2021, 06:00
Rick TaylorYou are welcome guys. Its taken a lot of experimentation, and a lot of failures to get at this process. I intend to write a more extensive article on this process once I've refined a few more things.
11 August 2021, 16:38
Ben MI would have spent a lot of time trying to sand striations before priming. I'd also heard put it in the sun, but I would have likely left them out there all day, I think you saved me from a lot of mistakes.
12 August 2021, 00:10
Rick TaylorBen, I have done both - multiple times. Sanding before priming with the right primer is just wasted effort - lots of wasted effort. If you leave parts in the sun too long they get so brittle I've had them shatter when dropped from my bench to the hardwood floor.
12 August 2021, 02:23
Ben MRick, thanks again for the tips. I not only built a vargas models kit, but I bought a resin printer of my own, and printed out another tank and just finished that as well.
20 October 2021, 21:03
