The sea wall is one of the most prominent scenic features on the layout. It's also pretty long - covering almost all of the 12 foot frontage of the layout. A few weeks prior to the Expo last July it was just a blank piece of plywood and our thoughts turned to make it into something more wall-like.
Exactly how to model the sea wall was something that caused us some head-scratching. We already have some retaining walls done with embossed plasticard and the big retaining wall behind the station uses Scale Scenes printed stonework. We felt that the sea wall needed rather more texture than the other walls because it would have been made using bigger blocks of stone which would be battered by the seas causing the joints to be more obvious. The shape of the wall near the station was also rather tricky because it has a couple of fairly tight curves as well as the typical lean that retaining walls have to stop them falling over. The tricky shape (combined with the difficulty of joining so many sheets) rather ruled out the use of embossed sheet as well.
We decided instead to try out using DAS modelling clay and embossing the stonework into this. Embossing 12 feet of wall was a pretty scary prospect too - clearly we needed to find a way to mass produce the stone texture rather than manually scribing it.
I tried out a few test pieces before attacking the main wall. The first try used manual embossing. This ended up looking like exactly what it was - a bunch of hand-scribed wobbly lines.
The next idea was to make some sort of roller to emboss the stonework. The first attempt used a piece of brass tube with fuse wire soldered to the outside in a stone block pattern. It was a real pain to make, even with just two courses of stonework. After embossing the DAS, the result showed some promise but the blocks were too large and I really didn't fancy making another soldered roller with more courses of blocks at half of the spacing that I'd tried for the test piece.
A visit to some local model shops turned up some polystyrene tubing. This seemed to offer an easier way to make the roller. I bought the biggest diameter available, which still wasn't very big at 10mm. I was rather worried that a 31mm repeat would not be enough to create convincing stonework.
The horizontal joints were added to the roller by wrapping some thin (10 thou by 20 thou) microstrip around it. The microstrip was wrapped around twice to make a double thickness and then fixed in place with solvent. The vertical joints were then filled in using small pieces of 20 thou square microstrip. I did about 4 courses and then took the embryonic roller to the next meeting for trials on the real sea wall.
In the meantime John had created the 'lean' of the sea wall using some old Artex. This also gave a nice rough surface to fix the DAS to. Getting a nice even layer of DAS proved a bit tricky but eventually we found some suitable bits and pieces to use as a sort of 'rolling pin'. We rolled out some sheets about 2 or 3mm thick and then cut strips to the right height for the sea wall. The Artex was given a coating of PVA and the DAS sheets were then pressed into place and the joints smoothed over.
Finally the roller was tried out on the wall (after lubricating with some water). We were pretty happy with the results so I took the roller home to add the remaining courses to do the full height of the sea wall. I made the lower courses slightly bigger vertically. I also made the lower blocks bigger horizontally by adding just 4 joints per course to the roller instead of 5 for the upper courses.
To cut a long story short the remaining length of the sea wall was embossed at the next meeting and we went to the Expo with the wall in that state - and looking very white as the picture below from the Expo shows.
I now needed to find a way to add coping stones that would be a reasonable match for the main sea wall. To do this I made a mould about 3 inches in length as a plasticard trough with microstrip inside to emboss the joints. Actually I made two different moulds - one with a flat bottom and one with a shallow 'V' shape to give different styles of coping for different stretches of the wall.
It took a while to figure out a way to use the mould without the new coping being pulled off when the mould was removed from the wall. Here is the method we ended up using.
The DAS was rolled into a sheet about 2mm thick. This was then cut into strips measured to match the width of the mould. These were put on top of the wall (after brushing with PVA). The mould was then used to emboss the stones. This method didn't have a 100% success rate - sometimes the coping would still come away when the mould was removed, but it was good enough to do the job.
The picture below shows all of the tools and test pieces. The thing that looks like a washer is a guide to ensure that the courses stay straight - this was attached with solvent to the end of the roller but it didn't stay attached. I'll glue it back on if I need to use the roller again.
One of the advantages of DAS is that it can be painted with watercolours so this is the way we did it. I painted one of the test pieces using some likely colours (ivory black and chinese white to get grey and then raw sienna for a brown hue plus occasionally some light red) to paint individual stones and was quite pleased with the result. The snag was that there was no way that it would be practical to paint each stone on a 12 foot long wall individually, so we had to find a different way.
The way we devised was to first paint the wall using a fairly light mix of the colours to represent the colour of the mortar. Once this was dry a darker mix was made up, avoiding using too much water. This was then brushed onto the surface, trying to avoid getting paint in the mortar joints. Each mix covered a fairly small patch and then a new mix was made up so there is inevitably some colour variation creeping in. The picture below shoes the work in progress - on the right I've just painted the mortar colour and on the left I've done the stonework colour.
Once this was done I then went over and picked out some individual stones using slightly different colour mixes. I usually looked for stones which hadn't picked up the basic colour very well, so this also fixed up any mistakes from the previous stage. I kept stepping back to check the overall effect and compare with earlier stretches of wall.
The next photo shows a finished section of the wall. We really must deal with that white beach.
This technique is still quite time consuming - we've spent several sessions on it and it the job is not yet finished , but we're more than half way along.