Avoiding the dull look when respraying

[Xen]

Just about to respray a large section of bodywork on the punto. Just needs a light rub-down with some fine wet-n-dry before i start (most of the paint is down to the primer now anyway.)

When I've tried spraying before, ive often found that in good light at the right angles, you can see dull/mat patches in the paint. Why is this? where am I going wrong?

If someone could bullet point the steps to take that would be great - just wanna make sure im doing it right

 

[Xen]

Surely we have a paint-spraying whizz on here somewhere?

 

[richcinq]

I have done a bit of spraying and found that if its too cold/hot or if its at all damp you get dull patches. The conditions need to be right to get a good finish. Also as a pfof sprayer once said to me-spraying a car is 5% spraying and 95% preparation!!

 

[-DrEw-]

also check for small pin holes in the primer, and make sure theres no degreaser/thinners left on the panel before painting over it

 

[jug]

When I've tried spraying before, ive often found that in good light at the right angles, you can see dull/mat patches in the paint. Why is this? where am I going wrong?

2 critical stages for a perfect finish are preparation and finishing.

what do you do before spraying?

you should get 1200 wet&dry used wet on the whole surface to be painted. dont be lazy, this stage takes a long time and a lot of work, but its critical to a good finish, the paint will show up any imperfections so you need to be fussy and get the surface as perfect as possible. use primer to show up any imperfections, only when the primer is smooth is it ready to be painted. this stage usually requires several coats of primer and several attempts at smoothing the surface.

what do you do after spraying?
you should flatten the paint using g3 and a mop, or alternatively very careful use of 2000grit wet&dry paper used wet. make sure your paint is thick enough to allow a few layers to be removed at this stage.

if you get both these stages right you'll have a mirror finish. if you just spray some paint onto your car you'll have a banger.

 

[Xen]

cheers jug but whats G3?
What do i do after that, should i put a clear lacquer on?

 

[GhostWKD]

G3 is cutting compound iirc

 

[-DrEw-]

should i put a clear lacquer on?

is that a joke?

 

[jug]

G3 is a liquid cutting compound made by farecla, think of it as liquid sandpaper. it is the easiest to use cutting compund on the market.

a laquer top coat is only really neccessary on certain types of metallic paint, and even then you dont really need it if you finish the paint layer correctly. if you do use laquer you need to finish that surface as well in the same way as you would the paint layer. it takes a bit more work to get the laquer swirl free, i recommended a gentle touch. i never bother with laquer, its more hassle than its worth, a good coat of carnauba wax does the job better.

 

[Xen]

your a star! thanks jug, ill let y'all know how it goes

 

[ajpepe72]

All modern 2 pack metallic paints need a laquer as they are supplied as matt base coats, so its the laquer that gives you your shine. solid colours are basically laquer with colour in so dont need a separate laquer.
Also what has not been mentioned is to make sure you wipe down the panels you are spraying with panel wipe before the 1500 grit sanding you do before you prime/paint. If you dont, any polishes,waxes, silicones etc on the panel will be sanded further into it and give you all sorts of problems.
Also if your getting colour variation then you need to adjust your spraying technique. your gun must be kept about 8 -10 inches from the panel and held completely parralell to the panel. if your tipping the gun at all then you will get a heavier build up of paint where part of the gun is closer to the panel. always start your paint flow off the panel and go across in a steady complete motion and let off the trigger only when your off the panel at the other end.