Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

So how do I go about painting it? Since you can't just go about the normal way of painting it since it melts in spray paint the the surface does not adhear to paint very well.

Asking because I really wanna make some Egyptian themed terrain

I'd go simple - a basecoat of cheap acrylic/"poster" paint mixed maybe 50/50 with PVA Glue (depending on the paint). If you want to add texture at the same time, you can add sand to the mix as well, which when dry is really easy and effective to drybrush.

Either way, slap it on, let it dry, then paint over it - once you have the first layer on, you might even be able to use spraypaint (Though you probably wouldn't need to) as the paint/PVA should protect the Polystyrene.
You can even buy quite nice, high pigment acrylic paint pretty cheaply, though I've used very cheap (around £1 per 250ml) paint quite effectively - and it's certainly less expensive to cover large terrain pieces in than using GW paint.

So a mix of acrylic paint, pva glue and sand?

I made some desert rock terrain a couple weeks ago that came out ok ish. I had the same issue trying to spray prime it so I ended up just throwing paint on it. Best thing I can say is to go buy yourself a couple bottles of apple barrel or some other cheap hobby paint and some brushes you do not mind ruining. I used an entire bottle of my base color just slopping it on. I had the most difficult time in areas that I had melted with acetone first but other then that, thick goopy $1 hobby lobby paint won the day. I attached a couple pics. Maybe one of the more experienced modelers here will have a better suggestion for you.
Good luck!

What Dark said, also small test tubs from DIY shops is useable and fairly durable

Just another option for texture. I tend to coat my polystyrene with spackle used for covering nails, holes etc in wallboard (again found at DiY in big tubs). You have to spread it on with a putty knife or something (fingers, cardboard stick whatever works). It gives you a slightly rough (sand or rocky) coating that sucks paint up. Warning, as above use a cheap paint to slop on a coat. I get the best results for ruins by not coating evenly.

There are a lot of options.

Generally though coating it in a layer or two of PVA is a good start.

i know some D&D terrain guys use mod podge with black mixed in to use as a semi primer sealer.

after with you ether use an airbrush or hand brush.

There are some foam safe spray paints though i cant comment on how well they work.

most people will just hand paint or airbrush though.

Skylark is on to something (nice rocks, btw). When I finally quit avoiding the spray vs. foam conundrum, it turned out to be no big deal, I'd been working too hard at it. Just don't spray. Cut and shape your foam, PVA or ModPodge plus sand adds nice texture and durability as the others have said, use a cheap, fat brush, and slather on some cheap acrylic paint from the art store. The time commitment isn't too different, ventilation is no big deal, and there's way more color choices. Then drybrush to keep it simple, or I've also seen a cool move where you literally draw on thin bands of color with red, brown, and gray Crayola markers for rock strata.

There's also a product called Foamcoat made specifically for, well, coating foam prior to painting. It is also good for concealing the non-uniformly solid foams (the bead type) better than just painting with PVA as it acts like a gap filler as well.

One thing I will say that the PVA+Acrylic Paint+Sand mix also does is protect the underlying polystyrene. Soft material like Polystyrene is quite susceptible to being dented, and if you're using expanded polystyrene, any damage often means you'll end up with little polystyrene beads going everywhere.

When you use the mixture with sand, it forms a tough but surprisingly flexible layer, which is very resistant to damage, and will also hold polystyrene together better than a straight coat of paint. Stuff like Spackle/Polyfilla can do a similar job, but tends to be quite brittle, and isn't necessarily as cheap.

You can mix stuff like plaster with pva to make it more flexible, though.

I tend to use plaster bandage on larger sections - then I go over it with a plaster/pva glue/water slurry. I also base my foam terrain on 3mm mdf. It prevents underside denting and the paint, sand, glue and plaster on top protects that/those sides.

SkylarkR6 wrote:
I made some desert rock terrain a couple weeks ago that came out ok ish. I had the same issue trying to spray prime it so I ended up just throwing paint on it. Best thing I can say is to go buy yourself a couple bottles of apple barrel or some other cheap hobby paint and some brushes you do not mind ruining.

What this guy said. I 100% have painted every terrain piece I own with craft paint. I'm not using my $6 a bottle high end GW paint to drybrush sand and rocks

As above, cheap, plentiful paint is great for terrain.

And as above... putting some glue on first helps to make a seal, and it also provides some dent resistance. You can buy a 4 litre / Gallon jug at hardware stores for a reasonable amount.

You can also get "no-slip" paint from stores. It's textured, and intended to be applied to things like ramps that would otherwise be smooth and potentially slippery. It's tough, being intended to be walked upon.

Looks like you can buy a gallon of it at Home Depot for $30 CAD.