Best filler for terrain making?

[mmcv]

I'm making a bunch of hills out of cardboard and filler at the moment and will soon run out of my current tub of filler. I've been using One Stroke lightweight filler which is fast drying, easy spread and nice texture but isn't all that robust, even when dried can still put your nail through it. 

Planning to use something more robust next time, any suggestions for fillers well suited to terrain making? Easy spreading and shaping but dries robust.

[Orcs]

I use a standard household filler, but mix with some PVA. This makes it quite hard. 

[paulr]

I add some paint to the filler PVA mix so chips don't show white

[Steve J]

I found Wilko's own brand filler to be perfectly fine. As the others have said, a bit of pva and paint helps too.

[Lord Kermit of Birkenhead]

The poundland stuff works for me

[mmcv]

Interesting, will try the paint and PVA trick with the next hill, that'll make painting them a bit easier. 

Are you mixing it with powdered filler or with the ready made stuff?

Sounds like the consensus is the best filler is the cheapest filler. 

[paulr]

I mix PVA & paint with 'the ready made stuff' as I use it mainly for basing so do lots of small batches

Did it once with powdered filler when doing trenches

[mmcv]

I mix PVA & paint with 'the ready made stuff' as I use it mainly for basing so do lots of small batches

Did it once with powdered filler when doing trenches

Yes one of my other ongoing terrain projects are those lovely trenches that are going to need a lot of filler as well at some point, though working on getting a load of them constructed first then fill en masse.

[Orcs]

I used the powdered filler as it was what I had at the time. Use with PVA and a small amount of water or paint

[Ithoriel]

I use tubes (rather than tubs) of Polyfilla, thinned with water where necessary, shaped with dental tools and clay sculpting tools .

Never tried or even thought of adding glue.

Most of my adventures in terrain making have been small scale, which may make a difference.

[mmcv]

I use tubes (rather than tubs) of Polyfilla, thinned with water where necessary, shaped with dental tools and clay sculpting tools .

Never tried or even thought of adding glue.

Most of my adventures in terrain making have been small scale, which may make a difference.

I do have a tube of polyfiller I just found in the garage so will try that. Also have some grout that might work as an option too.

[mmcv]

Mixed a bit of paint and PVA with some of my current tub of filler and things got weird. Went very gummy and almost dough like with only a little added. Had a hard time spreading it over the hill. Will see how it is when it dries but must be something in this particular filler that doesn't react well with the mix. So anyone reading this, avoid Quick Strike lightweight filler with this method. Unless you're trying for a slow lava flow style thing, then it would work well.

[Orcs]

If it goes like that add a little water

[mmcv]

If it goes like that add a little water

Yeah I did but couldn't find a sweet spot between gummy and runny. And too much water soaks into the cardboard and warps it. It's dried quite soft, so just think it's a bad mix with whatever makes this one light weight and quick drying. I'll try it with standard polyfilla as that'll be a more conventional filler recipe and likely work better. 

[Orcs]

Ok, I would not use cardboard as the base, I have never found any form of cardboard, that does not warp.

Suggest

Old CD's - Cheap but only 5" rounds

Plasticard - Expensive

Hardboard. - seal first with varnish or PVA. May still warp a little

MDF- generally ok. 2mm thick is hard to find in normal DIY stores, but you find 3mm. Bevel the edges to make it look thinner.  I have a 45° setting on my jigsaw that helps.

You can buy some random shapes from some wargames companies.

You want your filler to be the same consistency that you would use to fill a hole in the wall.