Right then,
Cellulose is a beautiful paint if you know what you're doing. If its your first time (cellulose virgin, the mind boggles!) then it can be tricky. It took me many years to be able to get a quality finish with cellulose.
These days its two pack that has taken over as the professionals choice. That is a paint and hardener system. It's relatively quick, dries to a gloss and can be baked. The downside is it contains isocyanates (I think the spellings right, its been a long time). Basically it will poison you without a decent ventilated mask as it produces a type of mustard gas. If you leave your gear dirty it will dry solid like a two pack glue and render your spraygun scrap!
So here are a few tips for cellulose.
1, Any cellulose thinners will do but try to get a slow drying one.
2, To get the perfect mix you need a No.4 Ford flow cup! The easy way is to mix it and use a clean metal spatula or clean screwdriver to stir. If the mix dribbles off the stirrer like water in broken droplets then its too thin, it needs more paint. If it runs off in a steady stream like condensed milk then its too thick! You want it to run off in a steady stream then break into a few drops at the end. That will be about the right mix.
3, If you can get a small bottle of anti silicone add 6 drops per litre of mixed paint, it helps deal with any local paint reactions. Thats another point, cellulose is very fussy and cleanliness is imperative (the car body not your armpits
)
4, If possible use 40psi with a good compressor.
5, Cellulose dries VERY quickly and that is one of the main reasons for a finish looking dull or dusty.
6, Hold the gun square to the panel (horizontally and vertically) approx 6 inches away. When you spray don't "fan" the gun. This will cause uneven coverage. Move your hand and arm parallel to the panel. If you're doing it right, it will hurt cos its not natural!
7, Do one panel at a time. Move slowly starting at the top of each panel left to right. Start the next stroke at the right and move back left under the first stroke but recovering the bottom third of the previous stroke. Don't start and stop on the panel you are painting, go beyond the edges so as not to get a build up and consequent runs.
8, Be smooooth. Watch the paint where it hits the panel, this is known as the "wet edge". If it looks dry or dull then slow down, if it looks like it might sag and run then speed up. Only slightly either way. The skill comes in keeping the wet edge constant, nice gloss but not too full.
120 w/d is way too coarse. This is normally used for roughing out filler. If you need to rub down between coats make sure the paint is dry enough first. If its not quite dry the paint will ball up and clog the paper. Leave it longer. Use light strokes, same direction as the gun with plenty of warm water and soap to lube the paper. If the water runs off your elbow in a steady stream you're doing ok! If you sand in circles by hand chances are you will see swirls in the finish. 800, 1000, 1200 are about right.
Cellulose does not like the cold and if you spray outdoors the paint might retain the thinners and take forever to dry. Also if its damp you can get a "bloom" on the paint. This looks like fine condensation and can be a pain to get rid of and will keep coming back. Don't compound or t cut until you are happy with the finish.
The answer to your question? No, there are no short cuts! Preparation is everything.
Good luck I hope it goes well.
