Das Clay for surface areas e.g. depots and roads

[dave182]

Hi All

I've a depot to surface over the weekend, and after seeing a couple of posts over Christmas of modellers using Das Clay, I thought I'd give it a go. 

I'm all set up but having done a bit more research I'm slightly concerned about the clay properties, specifically that it shrinks a good bit. 

Anyone got any experience or pointers with this? @David Holman has some excellent models using Das Clay and I don't think my surface area is much bigger than the areas he has paved on various layouts.

I've previously had great success using pollyfilla with scrim tape as a base for adhesion to the base board, with no shrinking or cracking. 

Any help appreciated!

 

Dave

Edited January 14, 2022 by dave182
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[Galteemore]

Take your time and build it up gradually. Use a coating of PVA on the baseboard surface to help it adhere.

Edited January 14, 2022 by Galteemore

[dave182]

Ok, 4 hours and 2 kilos of Das Clay later and we are here. So a wet surface and the scrim tape gave good adhesion to the mdf baseboard. I also noted Riverbank Railways Youtube short videos and left the clay a bit taller than the top of the rails so it can contract a bit, and I'll have a surface to sand. So despite the 'lumpy' look, it has actually quite a level finish. I'll leave it for now and take a look in 24 hours time to see how it is drying. I'll then need to score out the rails and let it dry some more before sanding and removing the side moulds. 

It was a very quick process, however I found it hard to blend each piece of clay I placed with the clay already in place. Lots of water helps. It also added two kilos to this piece of layout, so I might add some extra bracing under the board. But overall a quick and easy product to work with, and I'm encouraged to try it some for some other things like facades and walls. 

[Galteemore]

Excellent. Takes a bit of nerve to keep going - I know! 
 

 

[Brendan8056]

I used Das on a small (A3 surface area) tram layout for a French Railway Society competition. I did small areas at a time and impressed the cobble effect while the Das was damp, blending sections in using nothing more than a finger and some water. 3 years later and there is no  shrinkage that I can see. I used polyfilla many years ago and that was difficult to get a decent finish with.

 

[Angus]

I've used air-dry clay on a cobbled goods area for a 7mm project.

DAS is not the only show in town there are similar un-branded products around that can be found cheaper, most art supply stores carry them.

It's not really relevant unless you've a large area to do as the saving is only a few quid.

What I found works was (none of this is approach is unique to me):

- Spread a layer of undiluted PVA onto the the surface to be covered by the clay

- Break off a small blob of clay roll into a ballish shape (1-2cms in diameter) and push into the surface and flatten out.

- add the next ball so it overlaps with the previously laid one and blend in.

- use a drop of water (but only a drop!)to assist if the clay is getting a bit tough to blend.

- Keep the layers thin

- don't worry if you get a bit of cracking/crazing in the drying process, it looks disastrous but applying anther drop of water will enable you to blend out the cracks.

You've then the fun of creating the surface texture. I hand scribbed mine which was tedious at first but quickly became quite therapeutic if done in small bouts.

Hope that helps

Edited January 15, 2022 by Angus

[David Holman]

Funnily enough been doing the DAS this afternoon too. Got some in stone colour, which should help the painting process. Report tomorrow.

[Angus]

I used the terracotta colour in the photo above because the local art store was having a closing down sale and that was all they had discounted. 

Yorkshire/Scottish genetics have a lot to answer for! 

[Andy Cundick]

Used it  on Valencia and Courtmacsherry the stone colour is better in as much as it doesn't make so much  mess,Andy.

[jhb171achill]

Suppose you want to make a surface in 00 scale which is meant to look like an area originally gravelled, but most of it tramped down by now - smooth-ish but not exactly level, like a concrete or tarmac surface.

I presume this stuff is perfect for it - but what colour, how to "weather" it, and would it be a good idea to sprinkle some sort of very light grit on it to make it look "gravelly"? Perhaps light sand?

[David Holman]

Chinchilla dust, from your local petshop, JB. Very fine, and not made from pulverised, freeze dried chinchilla either.

 The more I look at prototype photos, the more apparent it is to me that, scaled down, surfaces are much smoother than we think. DAS clay is actually paper based I think, but dries in an hour or so when spread thin. 

 To be honest, Polyfilla powder, or Artex, especially when mixed up with a bit of pva, also works well, and you can add cheap water colour paint to it so it is precoloured. And, indeed chinchilla dust or find sand, ballast etc if you wish, though probably best to add such things after it has set.

[Galteemore]

And if you want ‘gravelly’, also worth looking at Gravett…..https://wildswanbooks.co.uk/Books/Modelling-Grassland.htm He’s a chinchilla advocate too.

[jhb171achill]

1 hour ago, David Holman said:

……..not made from pulverised, freeze dried chinchilla either.

No, that would be cruelty to rabbits……!

Seriously, excellent info as always, thanks!

[David Holman]

8 hours ago, Galteemore said:

And if you want ‘gravelly’, also worth looking at Gravett…..https://wildswanbooks.co.uk/Books/Modelling-Grassland.htm He’s a chinchilla advocate too.

Got all his books!

[dave182]

So an update on my adventures with Das Clay. I've no patience is probably the biggest lesson here! I should have practiced on a small area first. All the preventable things thst could have happened, happened. 

So lessons learned...

1.Apply a layer of pva glue on the surface you are sticking the Das Clay to.

2. Work with small amounts of clay at a time, and build it up. A little water helps

3. Allow it to dry out gradually. My shelf layout is in a very warm room, and the clay drying quickly makes it want to warp up and crack, and shrink

4. It is actually a very forgiving medium to work with. You can re-wet it and you can work it some more. 

6. Use a level clean surface if possible. I was recycling a piece of mdf board, and the drying clay had the effect of lifting a layer of the mdf where it may have been damaged from previous use

So after a couple of days drying this was the sorry state my 'concrete' slab was in...

Not deterred I sanded the whole thing down earlier today and wet the surface in a cool room, and this evening I took out the clay again and filled in all of the cracks and levelled the surface. It looks a whole lot better now. I'll leave it to dry again and sand it some more and see how it looks in a couple of days. I also ran a blade inside the rails in preparation for cutting out the channels for the wheels to run in.