Washing and priming Spartan Models

[Charbe86]

Not having worked with Resin models before Ive been looking for lots of tips online.  I found a few good tutorials related to forge world resin models that say washing and priming are a must.  I've never heard about this in reference to Spartan models, is that because it's unnecessary, or just so obvious to hobbyists used to resin that it doesn't get mentioned?

[Dakkar]

In my experience, Spartan Resin is superior to FW.

However, there's still that resin film on most batches, so I always wash my models in dish soapy water and let dry before I primer. I haven't had any huge issues with primer, even using Wal-Mart rattle cans, so I assume I'm doing okay there.  <knock wood>

[Charbe86]

Thanks, do you use actual primer, or just a spray paint undercoat?  We don't have walmart here so I'm not sure what you mean by a rattlecan

[Ruckdog]

Thanks, do you use actual primer, or just a spray paint undercoat?  We don't have walmart here so I'm not sure what you mean by a rattlecan

"Rattle can" is just short hand for aersol spray paint cans that "rattle" when you shake them to mix them. I use Rustoleum 2 in 1 primer and color for much of my modeling, as well as Krylon for my black. I know that a lot of folks also swear by automotive primer cans.

Honestly, I always used to wash my resin as well, but I had an interesting conversation with one of the founders of Secret Weapon at Adepticion about this. He claims that most release agents used today have been formulated such that they shouldn't cause issues with spray primers, and that flaking and peeling issues more often stem from some issue with the spray paint and not the mold release on the model. He warned the class I was in to be careful with getting resin too wet, since its a porous and absorbent material and it can react unpredictably to being wetted and dried (he specifically mentioned some Secret Weapon bases he was working on once that got brittle after being washed and dried). So, I would say it bears a little experimentation. If a particular primer you like works on Spartan resin without washing, you are probably good to go.

I will say that I've had the most problems with spray paints that are specifically designed for wargaming model applications; Army Painter sprays have given me no end of problems, as have Armory spray paints. I've had very very few problems with general purpose sprays from the likes of Krylon or Rustoleum.

[Charbe86]

That's brilliant, my wife works at a hardware store that sells rustoleum in both black and white. 

[Dakkar]

Thanks, do you use actual primer, or just a spray paint undercoat?  We don't have walmart here so I'm not sure what you mean by a rattlecan

Mine is just a flat white or flat black spray paint ... works about as well as some "pro" primers. But then I live where its horribly dry 10 months of the year :-)

[Ruckdog]

Hopefully there is one there that works for you! As Dale points out, though, you have to be careful about humidity using spray primers; high humidity can cause problems with adhesion and finish. I live in Virginia, where it tends to get rather humid. However, I have a spray booth, which lets me use my rattle cans from the safety of a climate comtrolled room .

Here is the type I use on my Terrans:

[Charbe86]

I live in the driest state of the driest continent in the world, finding a low humidity day will not be a problem, but it'll probably delay me a little.  Thanks for the help, I really want to get these ships painted right.

[Dakkar]

I just primered some resin ARENA REX minis with the Wal-mart Matte Black (and BTW, ALWAYS be sure you have the *matte* black or white). I did it after a rainstorm in relatively high humidity (for Colorado), and it still worked fine.

[Klingsor]

I have never had a problem with primer or colour sprays, only with clear, especially matt, varnishes that was not self-inflated. I have used the spray paints even in an unheated garage in the middle of winter though I do warm the cans first with a bath in warm water and our winters are quite mild if humid.
I di still wash everything before gluing or painting it, especially metal or resin. The idea of not doing so never really crosses my mind.
Porosity would explain why resin has such as affinity with superglue, it would just wick into it.

[RaptorEvolved]

If I may chime in here,...Spartan resin is by far some of the best casting I've seen. Forgeworld also has great models but one of the most detailed pieces I ever got from them was the Tauros  Elysian vehicles which was completely warped. I had cleaned and then submerged the resin pieces to straighten them in boiling water; this leads me to answering the first about the primer. Washing the model removes not only the release agent but also a very very fin film of residue left over from the casting process that sticks to the release agent once the chemical mix heat and begins to cure. And while most modern release agent arn't really a problem for primers the main reasoning behind this is to remove as much material from the bare styrene/resin. Alot of beginner mistake happen at this step when parts don't fit as sometimes the warping happens right after the casting process as the cast is released from the mold. Submerging the resin pieces in Hot water takes care of this problem, in addition let the pieces stay in the water a few minutes, they will completely reshape themselves.

When I wash the models I use an old toothbrush and make sure I deep clean the model, damp it dry and leave it overnight before I do anything with it. I find that on inspection the texture of the models surface is completely matte, also the grooves in the details/textures are stronger and cleaner. One of the things hobbyist forget is to leave the model to dry for at least 48hr before applying additional paint, you have to let the primer bond to the surface. You'll notice that after a couple days it's much harder to scrape off the primer.

As for the Clear-coat It depends what your painting a model for. If it's for realism/display I wouldn't use clearcoat as not all surface area look "matte". For personal and tabletop use. I stopped using rattle cans simple because frosting can happen through moisture at the tip of the nozzle head or due to atmo conditions and if you have a nicely painted model you always run the risk. I use matte or satin finish slightly dilluted(Vallejo,GW,Tamiya)through my Airbrush never had any problems.

[Klingsor]

I quite agree about how nice the Spartan resins are.

I picked up some 28mm 'scale' resin model boats and after a wash, priming and a basecoat, both sprayed on, when I started masking it some of the paint peeled off down to the resin, most alarming especially as I was using the (usually awesome) low tack Tamiya tape. I asked the manufacturer and they recommended using isopropyl alcohol to remove any residue after washing and a spray of matt varnish to seal coats, even primer and spray coats between layers. Their models fresh from the bag do have a 'greasier' feel than most resins so I assume this is the release agent, their models have some extremely fine casting so this makes sense.
I have both IPA (not the drinking sort) and spray matt varnish on hand so we shall see how this goes.

[Klingsor]

The manufacturer confirms it is the release agents and made some very good suggestions about using isopropyl alcohol to clean resin models and to use matt varnish to help paint adhere. I bought some engine degreaser as well as a plan B.

[Charbe86]

Great idea, I use Isopropanol all the time at work, that should have occured to me soonee.