prep before painting?

If you are using acrylic paints cleaning the section prior to painting is critical (in the case of acrylics I'd also recommend a light coat of enamel or laquer primer). Acrylics do not have the solvents in them that enamel and laquer does so they are not able to dissolve any grease or oil left on the surface. Enamels and laquers are less susceptible to that but it can still be a problem. Another reason for cleaning them prior to painting is to remove any dust or dirt left over from sanding.

Most people do wash them using warm soapy water. I prefer alcohol and compressed air, but that’s just my personal preference. Whatever you use allow the parts to dry thoroughly before painting.

Thanks MusicCity, Tiger has been washed and as soon as its dry I will spray first coat. I am using enamel in a rattlecan and I am going for that straight off the production line look as it will be my first major build since puberty and I want a finished tank to inspire me to continue the hobby. Users on the forum mention finishing off with a gloss coat? I presume they mean a clear coat to protect the finished paint job and decals, is this correct and which product do people recommend?

I don't think you'll see many armor guys telling you to use a gloss coat! The car modelers, maybe, but armor is nearly always flat.

My guess is that they mean a CLEAR coat, but not necessarily a GLOSS coat, or they mean for you to use it prior to the decals. I have used Testors Model Master clear flat and it works quite well. The recommended clear flat appears to be Polly Scale and I have some but haven't used it yet. Both of those are acrylic, but they do require an airbrush. Testors makes some clear flat in a spray can but it is a laquer so you need to be very careful using it.

Is your paint flat? And do you have decals for the tank? If so I'd recommend a clear gloss coat prior to the decals as it will make the decals much less likely to silver. Silvering is caused by air getting trapped under the decal and on a flat finish that is almost guaranteed. The best clear gloss for that is plain old Future floor polish that you can get at the grocery store, department store, etc. Apply it with a wide, soft brush and let it dry. Apply your decals and let them dry, then spray with a clear flat. If you use clear flat laquer, allow the decals and Future to cure for a couple of days and then mist the first couple of coats on. Laquer is death to acrylic sometimes so be very careful with the first couple of coats.

Another thing to remember is once you've washed your model, don't touch it with your bare hands - the natural oils in you skin will contaminate the surface you touch and the paint often won't adhere (had that happen to me at least twice). Go to your local pharmacy or drug store and buy some surgeons rubber glove and use them when handling your model (will also keep the paint off your hands when painting)