Thanks opps. I think you've confirmed what I already knew so I'll have to either use a brush and roller or go down the hiring route. I've read that as long as the mdf is prepped well and good paint is used the finish should come out very well just using the brush and roller.
Hand painting will be more forgiving. brushes and rollers are able to "push" paint into tiny holes/imperfections (unlike spray paint).
When handpainting MDF cabinets I use leyland Acrylic primer/UC. It is a substandard product but it doesn't clog my sand paper like most other acrylic primers do (it is also dirt cheap, about a tenner from toolstation). When dry I sand it with 180 or 240 grit stearate coated paper. I use random orbital sanders connected to dust extractors but it can be done by hand.
whilst sanding you will notice that the primer has caused the fibres to swell slightly, you will also notice parallel lines in the finish (a result of the manufacture process). I pretty much sand
almost through the primer, having treated it as a very fine filler.
I then dust/vacuum off the MDF, looking for any larger imperfections that need to be filled with Red Devil OneTime filler (which is sanded when filled).
I generally add some Floetrol to the leyland to help the acrylic primer flow but there have been times when I have run out and resorted to adding a drop of water.
The next coat is Dulux Trade oil based eggshell. I add the following to it
1. Terebene- an oxidising agent to help speed the curing process.
2. Owatrol- this helps the paint flow and level and enables a longer wet edge 9ie it slows down the initial paint drying).
3 A little bit of white spirit to thin the paint.
The next day i sand with 320 or 400 grit. Dust/vacuum again and apply the final coat of eggshell.
Depending on the colour you might need to apply a third eggshell.
In the old days i used to use rollers and then drag a brush over it to get even tramlines but now i use these paint pads for the larger areas
http://www.marinemegastore.com/product.asp?src=GBASE&pf_id=AQU_Q01811&jump=8&cat_id=MAIPAI004
(I would never use any of the foam backed paint pads made by other firms). the pad is faster than rolling and allows more even coverage and more subtle brush marks. Do not over load it or press too hard. drag it as you would a brush but allow it to twist slightly (so that you don't get a thick build up at the edges). I apply the paint quickly and zig-zag the pad to lay the paint off before then dragging it to get my parallel paint lines.
You will still need a brush for smaller areas and where the pad will not fit.
The replacement pads are about 6.50 but you can keep them in a Brushmate so that the are fresh for the next day.
Although 3 or 4 coats and lots of sanding sounds time consuming, spraying would require 3 or 4 coats and a hell of a lot more sanding (and cost).
