Although this subject was covered a while back it seems that some forum users would like a refresher, so this is a rough step-by-step as to how I go about repainting my locos. Please excuse the mishmash of photo's but some are new and some are old.
1.
To remove factory paint I use a product called SuperStrip by Phoenix paints, I also have a stiff-ish brush to help the fluid in those small gaps and agitate the fluid as needs require. Wear suitable gloves (latex car gloves are ideal) and do it in a well ventilated area - it is powerfully smelly stuff.
2.
I add some of the fluid into an old metal baking tray (with high sides). I tilt the tray by putting something under one end so the fluid is kept at one end, this helps you to submerge one side of your loco at a time. The picture shows the power of the stripping agent.
3.
Once both sides have been treated to the agent and you have brushed off all the old paint, you should have a shell that shows the original plastic colour.
4.
Pour some washing up liquid on the shell and rub it quickly over the body. Wash in warm water and leave to dry. Once dried you can see if any areas need further attention.
5.
Prime the body with a plastic primer - I use Halfords White plastic primer.
6.
Once the primer is thoroughly dry, think about what colours you will be spraying. You should spray with the lightest colour first and move upwards towards darker colours.
Mask off the areas to be protected from the spray using a modelling specific masking tape, such as the products by Tamiya,
which come in a variety of widths and have excellent low tack hold.
The picture shows where I have masked off the 47 and 37, firstly the yellow ends, then the grey roofs. Each masked up and sprayed separately.
7.
The colours can then be built up depending on the livery you have chosen. As I was doing a large logo livery I only had three main colours, so the blue would go on last - as it is a dark colour you can spray a grey primer as an undercoat for it. I use Railmatch paint and it can be a bit thin, so several coats may be required to cover the body sufficiently, hence the use of a grey undercoat for the dark colours can help reduce the waste of multiple top coat spraying.
If you have any questions I will try to answer them but like you I am not a professional and this is just my method. Many others exist and with a bit of searching I'm sure the internet will reveal further reading and help.
, and of course you can wash it down the sink when you're done. Mr Muscle shouldn't damage the plastic.