Hello Alex.
If you have built from MDF, you need to seal the body tub. You can buy MDF sealer, but diluted PVA glue does the job just as well. Just dilute you PVA with water so it looks like skimmed milk and paint it all over the tub, two coats along all the raw edges. When the sealer has dried, give a light sanding with fine sandpaper to smooth the slight lifting of the fibres that the sealer will have promoted, then recoat all the edges, and gently sand these again.
You are now ready to paint.
I handpainted mine, I used standard household white undercoat, and sanded down when it was dry, then I applied two coats of red gloss paint.
The gloss I used was yacht paint, but I think this was an overindulgence on my part, any good quality gloss from the major manufacturers would do. The underside I painted black gloss of no particular brand.
If you go down the rattlecan route, then after the initial sealing, the standard Grey primer and a gentle rub down followed by as many coats as you decide you require of the colour of your choice should do the trick.
I would estimate you will require at least two, possibly three cans of your Finnish colour, you might get away with one of primer.
If you have built from plywood, you will have a lot of grain filling to do on the on the flats as well as the edges before you can start to lay down any paint.
Regards,
Brian.
