Having assembled the Parkside Dundas kit of a 7 plank, 12 ton open coal wagon (see this post) the next step was to prepare it for painting by weighting the wagon and priming the surface.
Whilst I don't want the wagon to be so heavy that it can't be pulled or pushed along the track it does need to be heavy enough to ensure that it stays on the rails. The plastic kit is very light and when pushed around my layout (I was using the Pug to push it) it would derail at every set of points. Essentially the bumps in the track cause it to lift clear of the rails and when gravity takes over, more often than not it doesn't return cleanly. When I was younger lightweight models were made heavier with big chunks of lead -- my model of Flying Scotsman has a big chunk in the tender. Unfortunately lead isn't really good for you and so the powers that be have made it difficult to buy. Fortunately there is an alternative that is actually easier to use.
One of the problems with using lead to weight a model was finding somewhere to put it. As I haven't yet decided if I want to model the wagon as full or empty I don't want to put a weight inside it. This means any weight has to be added underneath where there isn't really much space. The modern/safe alternative to lead is Liquid Gravity (I can't find a sensible page from the manufacturer so I'm using the page from my local model shop where I actually bought some). Essentially Liquid Gravity is lots of very small yet heavy metal balls that easily flow and fill small areas and holes which you seal in place using superglue. Given the layout of the underneath of the wagon it was easy to add quite a bit of weight without affecting the appearance.
Once weighted down the next step was to use primer to ready the model for painting.
As you can probably tell from the photos I'm using an aerosol can of Humbrol grey primer for this job. Having never tried to spray paint anything before I'm actually quite happy with the result. It took almost no time, compared with doing it with a paintbrush, and it's a much more even coat than painting would have produced. The only downside being that I forgot to mask off the brass holes for the wheels so these will need cleaning up before the model will run smoothly but that shouldn't be too much of an issue (I hope).
The next step will be to paint the wagon.