Monday, June 6, 2011

Ballast It!

After indulging in a week's holiday, hence no postings, I thought I would start again this week by explaining the process that we use to ballast our track. This can be one of the more fiddly and time-consuming jobs that has to be done on a model railway layout - especially when you have one that, like ours, is rather large.
Of course the quickest and easiest way to apply 'ballast' is to use foam underlay from the likes of Hornby and Peco, as shown in below:
However, this can work out rather expensive if as, again, your layout is a large one. I have also heard it said that the foam can perish over time, especially if the layout is in a location that is prone to damp and cold during the winter months. 
Also, foam does not look as realistic as proper chippings and that is the main reason why we chose to use that method to ballast our track rather than the foam.
In the picture below you will see that I have put cork between the track and the base board. This is purely to allow me to create a ballast shoulder. If you do not want a shoulder then it is perfectly acceptable to lay the track directly onto the baseboard. Some people say that adding the cork also helps with noise reduction but I have not found this to be the case. However, I do like to lay the track onto cork because it does help to create a flat surface, something that is essential for trouble-free running.
Once the track is secured to the cork I sprinkle the ballast between the sleepers, usually a short section at a time, say about six inches. Once I have sprinkled sufficient ballast onto the track, I use a small artists brush to spread the ballast evenly and to remove it from the sleepers, as shown here:
You can also tap the baseboard on either side of the track as this can help the ballast to settle and bed down. I continue sprinkling and spreading until I have ballasted between the rails and, also, along the sides to create the shoulders. Then I use a steel ruler, or something with a similar straight edge, to gather in any loose bits of grit and so neaten the ballast at the sides of the track, as shown below:
At this stage I could start to add the glue but some people suggest that you dampen the ballast first in order to help the glue mixture flow better. I must admit, I have added the glue without wetting the ballast first and have found that it flows okay; so, whether you do this or not is really personal choice. However, for the purposes of this posting, I have sprayed the ballast using a garden mister with the nozzle set to a fine mist.
After wetting the ballast I then apply the glue mixture using a small artists brush. A pipette or syringe would do the job just as well but you do need to soak the ballast to ensure that the glue penetrates and binds all of the grit. The glue mix that I use consists of 40% PVA glue, 60% water and a drop of washing up liquid, which helps the mixture to spread. It is usually best to mix your glue thoroughly and then leave it for 24 hours to settle down before using it, giving it a quick stir before doing so.
Once the glue has been applied it will need at least 24 hours to set, I usually give it a couple of days to make sure it is fully hardened. After that I  give the track a thorough clean to remove any bits of ballast from the sleepers and, more importantly, also remove any that is stuck to the inside of the rails. Not to do this can lead to, at best, rough riding and, at worst, derailments. It is also very important to clean the top of the rails to remove any grit and/or glue residue.
We have a couple of old and tatty test coaches which we use for testing track and clearances etc and I always run these over any freshly ballasted track to see if they run smoothly.
Once this is done I use a vacuum cleaner to pick up all of the loose ballast and other debris before I allow trains to go anywhere near a newly-ballasted section of track. Using the vacuum cleaner also acts as a good test for the integrity of the glue. If I have not used sufficient glue or somehow missed any of the ballast, the cleaner will simply suck it up and I will have to reballast those bits again. 
When all of this work is completed I hope to end up with track that looks something like it does in the picture below:
Obviously I have used unpainted track here but, if you want to paint the sleepers and sides of the rails, it is obviously better to do so before ballasting. I have also used a single grey colour of ballast, however,  other colours exist and you can also mix colours to give a more realistic look.
One note of caution when it comes to ballasting points: you must make sure that you avoid getting ballast and glue anywhere near the moving parts. We have many, many points on our layout and I have ballasted them all but I always take particular care when working around the moving bits. I use just enough ballast to give the suggestion that it has been done, with no baseboard or cork showing through, and I am also very, very careful when applying the glue. I did manage to gum up a couple of points when I first started ballasting, which is not a good idea, but that only served to make me more careful in the future.

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