Using DAS on plasticard

[Captain Kernow]

I am planning on building a 4mm brick and stone structure, using plasticard as the basis but with DAS cement on top, scribed to represent an individualistic pattern of brick and stone.

 

I'm sure I've read of DAS being used on plasticard buildings before, but does anyone have any tips to help the DAS adhere properly to the plasticard, please?

 

I am assuming that the surface of the plasticard will as a minimum have to be roughened.

 

Thanks.

 

[David C]

I've used DAS on many of my stone buildings over the years using many of the techniques outlined in Dave Rowe's classic book "Architectural Modelling in 4mm Scale". I don't know if its still in print, but it is well worth acquiring if you can get hold of a copy.

 

DAS is simply smeared onto the styrene sheet and left to dry. You can sand the styrene beforehand if you wish - I do in any case, but only so I can see pencil marks - but I don't think it absolutely necessary. Whilst still wet, the DAS is impressed with the outline of the individual stones using the wrong end of a scalpel blade (careful!) or, as Mr Rowe suggests, bits of brass sections. As you proceed, you may (will!) find yourself thinking certain sections aren't up to scratch, but if the DAS is still damp, you can wet it and redo what you don't like. There is a tendency for the courses being embossed to either head upwards or downwards. Of course, some prototypes do wander up and down - that is part of their appeal - but if they all head in one direction, it wont look very realistic. It is worth keeping an eye out for this - I usually look at photos of real buildings to see how they vary. 

 

How does DAS adhere to the styrene? This is the clever bit (and it works with Polyfilla and other similar fillers). When dry, DAS is porous, so it simply needs flooding with Mek Pak to make it adhere. Make sure the sides and ends and the window and door apertures are soaked as well. It evaporates pretty quickly and can be further worked on almost immediately.

 

Dave Rowe recommends DAS is spread over the building or whatever in a thinnish layer of about 1mm for stonework with mortar which is in good condition and a thicker one of about 2mm for walls with mortar which has decayed or fallen out. I prefer layers of about 2mm partly because if the building you are creating was built of dressed stone, you will need to sand the DAS down to represent it (after it has dried and been flooded with solvent). You can also add mortar by applying a watery mix of plaster to the courses and then wiping it off the surfaces of the stones before it dries. As the plaster mix dries, it shrinks enough to leave a 3D impression of stones which are proud of the mortar.

 

One other thing I would advise is to make the stones at the corners of the building individually out of styrene and those around door and window apertures. The reason is that it is virtually impossible to do this with DAS and you usually end up with a rounded corner, which looks unrealistic to my eyes at least.

 

I've never used DAS to represent brickwork, but I'm not sure if it would work. DAS is fibrous and you may find it difficult to get the straight, hard outlines of bricks. You could try ordinary Polyfilla or similar instead. 

 

I'll attach a couple of shots of some of the buildings built with DAS on my layout. Ignore the goods shed as that was built using Wills sheets, but the low relief maltings at the rear of the layout and the barn in the other photo were made of styrene and DAS.

 

Have fun.

 

David C

 

 

[Siberian Snooper]

I paint some solvent on to the plasticard and then apply the DAS and then dribble some more solvent on to the DAS and roll the DAS to the required thickness.

 

 

[Paul H Vigor]

4 hours ago, David C said:

I've used DAS on many of my stone buildings over the years using many of the techniques outlined in Dave Rowe's classic book "Architectural Modelling in 4mm Scale". I don't know if its still in print, but it is well worth acquiring if you can get hold of a copy.

 

DAS is simply smeared onto the styrene sheet and left to dry. You can sand the styrene beforehand if you wish - I do in any case, but only so I can see pencil marks - but I don't think it absolutely necessary. Whilst still wet, the DAS is impressed with the outline of the individual stones using the wrong end of a scalpel blade (careful!) or, as Mr Rowe suggests, bits of brass sections. As you proceed, you may (will!) find yourself thinking certain sections aren't up to scratch, but if the DAS is still damp, you can wet it and redo what you don't like. There is a tendency for the courses being embossed to either head upwards or downwards. Of course, some prototypes do wander up and down - that is part of their appeal - but if they all head in one direction, it wont look very realistic. It is worth keeping an eye out for this - I usually look at photos of real buildings to see how they vary. 

 

How does DAS adhere to the styrene? This is the clever bit (and it works with Polyfilla and other similar fillers). When dry, DAS is porous, so it simply needs flooding with Mek Pak to make it adhere. Make sure the sides and ends and the window and door apertures are soaked as well. It evaporates pretty quickly and can be further worked on almost immediately.

 

Dave Rowe recommends DAS is spread over the building or whatever in a thinnish layer of about 1mm for stonework with mortar which is in good condition and a thicker one of about 2mm for walls with mortar which has decayed or fallen out. I prefer layers of about 2mm partly because if the building you are creating was built of dressed stone, you will need to sand the DAS down to represent it (after it has dried and been flooded with solvent). You can also add mortar by applying a watery mix of plaster to the courses and then wiping it off the surfaces of the stones before it dries. As the plaster mix dries, it shrinks enough to leave a 3D impression of stones which are proud of the mortar.

 

One other thing I would advise is to make the stones at the corners of the building individually out of styrene and those around door and window apertures. The reason is that it is virtually impossible to do this with DAS and you usually end up with a rounded corner, which looks unrealistic to my eyes at least.

 

I've never used DAS to represent brickwork, but I'm not sure if it would work. DAS is fibrous and you may find it difficult to get the straight, hard outlines of bricks. You could try ordinary Polyfilla or similar instead. 

 

I'll attach a couple of shots of some of the buildings built with DAS on my layout. Ignore the goods shed as that was built using Wills sheets, but the low relief maltings at the rear of the layout and the barn in the other photo were made of styrene and DAS.

 

Have fun.

 

David C

 

 

If flooding with MEK, ensure very good ventilation - I wouldn't do it in the house! 'Glue sniffing' is not recommended!

[Captain Kernow]

Thanks everyone for the suggestions above.

 

Admittedly, I was thinking of scribing the stonework on the dried-out DAS (once sanded to an acceptable finish), but I'm getting the impression that this may not be recommended, as compared to scribing wet DAS.

 

I do know that tile grout is fairly easy to scribe when dry, also Polyfilla type fillers, so presumably either flooding the dried tile grout with MEK or applying it just before the tile grout would still work?

 

The structure this is meant for is a road-over-rail stone bridge.

 

Thanks.

 

Edited October 25, 2023 by Captain Kernow

[Torper]

2 hours ago, Captain Kernow said:

Admittedly, I was thinking of scribing the stonework on the dried-out DAS (once sanded to an acceptable finish),

 

 

Not having any experience in using DAS I'd have thought that too - maybe you could try both methods and report back?

[Greengiant]

I prefer scribing DAS when dry, you don’t get any dragging, plus you can draw your scribe lines in pencil before committing to actual scribes.

 

[ColinK]

I prefer to scribe the DAS when it’s still wet. For the horizontal courses I just use a long strip of thin plasticard across the full width of the building, while for the vertical courses just jab a short piece of plasticard (or screwdriver).  Once it’s dry just a

light sanding and it’s ready for paint.

[Siberian Snooper]

I scribe DAS when it's dry, otherwise it throws up furrows.

 

 

[figworthy]

8 hours ago, Captain Kernow said:

Thanks everyone for the suggestions above.

 

Admittedly, I was thinking of scribing the stonework on the dried-out DAS (once sanded to an acceptable finish), but I'm getting the impression that this may not be recommended, as compared to scribing wet DAS.

 

I do know that tile grout is fairly easy to scribe when dry, also Polyfilla type fillers, so presumably either flooding the dried tile grout with MEK or applying it just before the tile grout would still work?

 

The structure this is meant for is a road-over-rail stone bridge.

 

Thanks.

 

 

Good evening Mon Capitain,

 

I've done quite a bit of DAS scribing, and it has always been done dry.  As others have said, you can draw on your pattern with a pencil, and you don't get furrows.  My weapon of choice is a .6mm nickel silver lace pin held in a pin vice.

 

What I can't remember is what I added to the surface of the plasticard before I put the DAS on.  I think it was PVA.

 

I've also used coving adhesive (which has a technical name which currently escapes me).  Again done dry, but in this case, it is cast (make a mould using some styrene L shaped strip).

 

Adrian

[GONK43]

Another method i have been experimenting with, and shows good results.

I use celotex. carve your stone work, spray with rustoleum stone, then dusted with black/grey powders.

Shows a granite effect, but other stone can be achieved.

I stick card to the back of celotex with pva.

Only issue is if making buildings, the corners can be tricky, but with mitre and pva it`s possible.

 

[Olive_Green1923]

On 24/10/2023 at 16:41, David C said:

I've used DAS on many of my stone buildings over the years using many of the techniques outlined in Dave Rowe's classic book "Architectural Modelling in 4mm Scale". I don't know if its still in print, but it is well worth acquiring if you can get hold of a copy.

 

DAS is simply smeared onto the styrene sheet and left to dry. You can sand the styrene beforehand if you wish - I do in any case, but only so I can see pencil marks - but I don't think it absolutely necessary. Whilst still wet, the DAS is impressed with the outline of the individual stones using the wrong end of a scalpel blade (careful!) or, as Mr Rowe suggests, bits of brass sections. As you proceed, you may (will!) find yourself thinking certain sections aren't up to scratch, but if the DAS is still damp, you can wet it and redo what you don't like. There is a tendency for the courses being embossed to either head upwards or downwards. Of course, some prototypes do wander up and down - that is part of their appeal - but if they all head in one direction, it wont look very realistic. It is worth keeping an eye out for this - I usually look at photos of real buildings to see how they vary. 

 

How does DAS adhere to the styrene? This is the clever bit (and it works with Polyfilla and other similar fillers). When dry, DAS is porous, so it simply needs flooding with Mek Pak to make it adhere. Make sure the sides and ends and the window and door apertures are soaked as well. It evaporates pretty quickly and can be further worked on almost immediately.

 

Dave Rowe recommends DAS is spread over the building or whatever in a thinnish layer of about 1mm for stonework with mortar which is in good condition and a thicker one of about 2mm for walls with mortar which has decayed or fallen out. I prefer layers of about 2mm partly because if the building you are creating was built of dressed stone, you will need to sand the DAS down to represent it (after it has dried and been flooded with solvent). You can also add mortar by applying a watery mix of plaster to the courses and then wiping it off the surfaces of the stones before it dries. As the plaster mix dries, it shrinks enough to leave a 3D impression of stones which are proud of the mortar.

 

One other thing I would advise is to make the stones at the corners of the building individually out of styrene and those around door and window apertures. The reason is that it is virtually impossible to do this with DAS and you usually end up with a rounded corner, which looks unrealistic to my eyes at least.

 

I've never used DAS to represent brickwork, but I'm not sure if it would work. DAS is fibrous and you may find it difficult to get the straight, hard outlines of bricks. You could try ordinary Polyfilla or similar instead. 

 

I'll attach a couple of shots of some of the buildings built with DAS on my layout. Ignore the goods shed as that was built using Wills sheets, but the low relief maltings at the rear of the layout and the barn in the other photo were made of styrene and DAS.

 

Have fun.

 

David C

 

 

This is a very useful read as someone who has started dabbling with Das. My previous  stone buildings have been Wills sheet.

 

Thus far I have done a small test wall by putting Das on to mounting board, and then scribing it with the back of a blade. Following a tip I read in Railway Modeller, I then rolled a ball of tin foil over it to get some texture.

 

The thing I’m struggling to find a solution for is getting relief on the stones. The Wills sheet do this very well, with different degrees of relief between the stones. Do you have any tips on how to achieve this?

 

 

[GONK43]

OK Olive_green1923, it is quite difficult to show someone what to do in words not pictures.

To achieve this finish, take celotex, remove silver covering, then using any means of scribing, i used a flat thin screwdriver, push lightly into the celotex horizontal lines, the length of the wall you require. Now this relief is not to scale, just what looks good for me. Then scribe vertical lines as individual stones between the lines.

I then use Rustoleum STONE and spray the entire scribed wall. Allow to dry, then I use black, grey powder to weather to you taste. Thats basically it. Attached some pics to try to show the celotex pre painted.

I also glue to the back of the celotex some card, using pva. This allows me to stick it to other materials, i.e. plastic. It also makes good tarmac roads, and platforms. The roughness of the celotex, gives you relief on stones.

[David C]

What scale are you working in - and what kind of stone are you trying to reproduce? If 4mm, I'm not sure you need much in the way of texture, particularly if its dressed stone. When it's dry, you will probably need to sand it down a little. As Siberian Snooper points out, you may well throw up furrows if you impress the DAS when wet. I've only ever sanded with fine grade sandpaper, but you could try with a medium or even coarse grade instead.

 

Incidentally, I've also sanded down the Wills coarse stone sheets. Although its a reasonably good product (it's the only Wills stuff where the courses actually match up to each other!), it is very recognisable. It's so common these days that you only need to look at a layout and you know what the builder has used! Sanding the sheets down a little changes their appearance considerably, depending on how heavily you do it. If you want a fairly flat finish, you may lose some of the courses between the stones, but these can be scribed in again - but that rather defeats the object of using the Wills sheets in the first place. A light sanding can still make the sheets different enough from the unsanded ones.

 

David C

 

 

[Olive_Green1923]

3 hours ago, David C said:

What scale are you working in - and what kind of stone are you trying to reproduce? If 4mm, I'm not sure you need much in the way of texture, particularly if its dressed stone. When it's dry, you will probably need to sand it down a little. As Siberian Snooper points out, you may well throw up furrows if you impress the DAS when wet. I've only ever sanded with fine grade sandpaper, but you could try with a medium or even coarse grade instead.

 

Incidentally, I've also sanded down the Wills coarse stone sheets. Although its a reasonably good product (it's the only Wills stuff where the courses actually match up to each other!), it is very recognisable. It's so common these days that you only need to look at a layout and you know what the builder has used! Sanding the sheets down a little changes their appearance considerably, depending on how heavily you do it. If you want a fairly flat finish, you may lose some of the courses between the stones, but these can be scribed in again - but that rather defeats the object of using the Wills sheets in the first place. A light sanding can still make the sheets different enough from the unsanded ones.

 

David C

 

 

Thanks David. Ideally I’d be trying to do coarse stone in 4mm - so akin to the Wills sheets essentially, where the stones have different relief as well as rough texture instead of smooth. Indeed, the Wills sheets do align, but this isn’t always the case depending on the dimensions of the walls. So yes essentially my query was how to emulate the appearance of coarse stone. Tin foil helps to give some texture, but it doesn’t change the relief between different stones.

Edited January 27 by Olive_Green1923

[David C]

I've never felt the need to add texture to DAS, but you could try any or all of the following:

 

1)    How about using cloth of some kind (with a loose weave) and either laying over wet DAS or wrapping your finger round the cloth and then dabbing the DAS.

2)    Alternately, sprinkle very fine flock powder onto wet Das and then pressing it in. You might have to seal it after it is dry. Have a look at Eine Sekundärbahn in Layout topics, particularly Page 2. You may not appreciate German railways and the buildings are all plastered, but Tim Hale's scenic work is pretty good.

3)    Yet another alternative has just occurred to me: sprinkle with different sizes of flock!

 

If you want individual stones to project out differently, the only thing I can think of is to cut out some random bits of styrene of varying thicknesses and sizes and then stick them to the base before applying the DAS.

 

Hope this helps.

 

David C