"Prepping plastic for acrylic paints" Topic

For the first time in over 40 years, I find myself about to paint some soft plastic figures: Caesar US moderns.

I will be using Vallejo acrylics. Previously, way back then, I was using Humbrol enamels and always had issues with paint flaking off thin items such as swords and rifles. I am hoping acrylics will be more durable.

Are there any parricular tips I should be using for prepping the figures? For instance, is it necessary to do a primer undercoat as I would do with metal figures?

The most important thing is an overnight soak in hot soapy water, a thorough rinse and an air dry. This removes any mold release compound and is necessary for adhesion.

I generally prime afterward, but I'm like that.I've done and still do several different primes depending on circumstances, but your best all-round bet might be Army Painter sprays, which adhere well to the plastics and still have that microscopically rough primer surface. I do sometimes brush prime with a mix of acrylic paint and PVA, usually with good results.

Whatever you do, remember when you're done painting you need a flexible cop coat. Many people use a dilute acrylic floor polish. I either use Woodland Scenics Terrain Cement or brush on PVA with a cheap wet brush.

Good luck. I find modern soft plastics to be well-proportioned, nicely detailed and sturdy. If I'd known some of the techniques 40 years ago, I might own less metal.

Diluted Tacky Glue brushed on and then spray primer. I can aggressively bend rifles with no cracking.

Hmmmmm… I would have thought Gesso. I've never done plastics but do have some I intend to paint and read here at TMP that Gesso was the ticket. Is this incorrect?
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Thanks for the tips so far.

Is Tacky Glue the same as PVA.

Hi Alan,

Typically on threads like this you will hear about quite a few different techniques (often as many as there are posters), all of which I'm sure work well. It just goes to show there is some wiggle room here.

My method (learned from other TMPers, by the way) is as follows: Give them a good scrubbing in soapy water, then let dry.

Next, spray with Krylon Gesso (Hobby Lobby carries this, I'd guess Michael's does as well). Let dry. Then paint as you would any other figure.

Finally, brush with either PVA or Mod Podge (which is a slightly thinner PVA made for this sort of thing – Michael's carries it). In the old days I'd then give them a spray of varnish, but I skip this now, as I hate spraying. Instead I generally give the figures one more light coat of Mod Podge/PVA on "touch points": exposed edges like elbows, knees, heads or shoulders, those areas where they're most likely to be handled. Slightly odd, I know, but I like to think it helps. And there you are, a robust figure that should withstand wear and tear at least as well as most metals.

Good luck, and, whichever method you choose, have fun!

Daryl

One last thought: Honesty compels me to admit that sometimes I'm so lazy I don't even wash the figures in soapy water – I just take them right out and spray – and I've yet to see any problem arise from this.

I use gesso with great success. the diluted pva works very well as well. some people "etch" before hand with diluted vinegar after washing with warm soapy water but I have never done that.

I wash/dry
Rustoleum gray spray primer (recently experimented with Plasti-dip's tan camo spray but experienced a little peeling but did not wash the test figures first, that may be why)
paint with Vallejos
seal with minwax satin poly with oil paint mixed
dull cote spray

View from someone also in the UK :-)

I wash /dry
Undercoast with diluted PVA (or just use the stuff for kids from Hobbycraft which is diluted already)
I then paint them.
Finally varnish them.

Not had any problems with swords or bayonets flaking since I started using the PVA method

Mike

Apologies, Alan, should have checked that. Listen to Mike!

I brush on liquitex black gesso and paint with acrylics (mostly coad d'arms, some reaper, some vallejo) and then varnish with vallejo matte varnish. Some times I'll do a pledge/future ink shading wash. If I do, I make sure to give the figures a full day to dry before applying a matte varnish as I don't want to reactive the wash.

Tacky glue and mod podge are just different formulations of PVA. Often with higher glue content and less filler. Mod podge has stuff added to keep it from reactivating with moisture like many types of PVA tend to do.

Nothing wrong with watered down PVA for bendy plastics. I find the gesso to be stronger and to give a surface with more tooth for paint to stick to, but the PVA approach totally works too.

The key is really flexible primer, flexible paint, flexible sealer.

Very many thanks indeed.

Alan

Protip: soldering iron (for a half of second) helps with making bend rifles (which are common with Ceasar Miniatures) straight.
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Tacky Glue is a little stickier and I think more flexible. I prime while it's still sticky. Works well for me.

Do you thin the tacky glue or mod podge before using as primer or sealer?

Also, has anyone use the Krylon spray opaque gesso as primer AND the clear gesso as a sealer?

Thanks!

Something you may come to really appreciate about using gesso as a primer on soft plastics is the way it soaks up the acrylic paint. I use white spray gesso from Hobby Lobby (40% off coupon of course). If you thin out your Vallejo paints you get a lot of texture, almost like a wash (I wash afterwards). Really helps on more modern figures with uniforms of mostly drab greens and browns. Try using Vallejo khaki with a green wash.

Sorry for resurrecting this thread again.

I have seen suggestions of spraying plastic figures with the undercoat used in the motor trade for prepping plastic parts such as bumpers (fenders if on the other side of The Pond!) prior to spraying.

Anyone with experience of this technique?

Alan

Not a fan of them tbh. The motor trade primers are designed for rigid plastics. With our toys, the old approach still works.

I favour experimenting as each plastic responds differently – my Caesar WW2 figures have been primed with Warlord Army Painter fans – works fine. But I use the Army Painter dips and a matte spray, so there is a lot of good quality varnish involved as well.

I say experiment though as I have found the Vallejo acrylic polyurethane primers sticks brilliantly to Airfix, but less so the HaT soft rubber. So each is different.

As a final recommendation – Liquitex acrylic matte medium is a very good, straight from the bottle, watered down pva (not actually watered down – but it feels like it). I use that where I experience problems and it works a treat.

Enjoy your figures – a lot of really good 1/72 plastics out there these days

Marc

Marc,

Thanks for the tips. My plastics are mostly the harder sort used by Caesar.

Would you use the car plastic primer on the like of hard plastice kits such as tanks and planes?

SHOW THE DAMN CAN… what is all this "gesso" business? JeEZE

It took me 1 minute to search Google for the following:

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Gesso also comes in a brush-on variety, in several colors: white, gray, and black. I prefer the brush-on variety. It is sold as a painting easel/canvas primer, it is water-based, and acrylic, not oil-based -- easy to clean up with soap and water, no harsh chemicals needed.

Been using it for plastic mini's for a few years now. Quite a good product. Sucks down on the surface of the mini as it dries, forming a tight skin. Takes acrylic paints quite well. Cheers!

Sorry Alan – missed your comment.

No, for tanks etc I just use any spray – currently FoW WW2 colours. They stick just fine. I had a bad experience with the car plastics primers a few years back and have a big bag of figures and flaked off primer in it, which is too demoralising to clean up…