spray painting what have i done wrong

[automania]

ive just sprayed an ifor williams back door, first of i give it a couple of coats of etch primer then some 2k black paint, about four coats. thing is the paint, from certain angles, looks as tho there are wet places, as tho id literally just sprayed a line across, there are quite a few of these.  it also feels a bit like fine sandpaper. for the paint i used autopaint "ap basecoat thinners". anyone know whats gone wrong? cheers

[ben-dent]

was the panel straight, before starting to paint, if not did you straighten the pannel or filler it??

did you wet flat back  the paint after each coat??

you were using 2K primer and thinners wernt you??

how long did you leave each coat to dry / cure between next coat??

what conditions were you spraying in?? (Dusty, Cold, Damp)

i think you may have got a reaction between the primer and black, or there is a bit of dirt or damp between the paint

i am not a proffesional sprayer, but have sprayed and worked in a couple of companys who do spraying, so i may be barking up the wrong tree

[automania]

the panel was a brand new piece of aly so fairly straight.
i didnt wet and dry it proper i jsut give it a quick dry rub with wet and dry.
not sure about the thinners, thats why i put what it was but think it should be the right one as i bought it with some 2k a couple of years ago. the primer i bought then went into the paint shop and told them it was for etch primer.
left it about half an hour or until it felt dry.
conditions were outside today.

cheers for the reply

[squaddie_fox]

the age of the paint may be a factor aswell as not rubbing down each coat properly aswell. i would also give it a bit longer between coats. try rubbing it down further as it is with wet and dry, then apply a couple more coats (with more time for drying between them) and a lacquer.

[horsethief]

I use a can of black(Wilko's cheapest),then a good helping of mud and dirty water gets rid of any imperfections.I know this dosn't help,but I only scrape or dent it again. :D

[muddyoffroader]

sounds like ye didnt wet and dry the panel before spraying to me, sand it all back with wet and dry (800grit should do it) then primer and sand that back with eiither 1000grit or even 1200, give it a clean and a wipe down with alcoholic panel wipes then spray it make the paint a wee bit thinner than normal,  if i mix 1/2 a litre i normally stick about an egg cup more thinners in.

just 1 more thing, you did put hardener in the 2k paint?

oh could also be ye spray gun clogged or set wrong, ye should have about 2 & 1/2 bar when spraying then a wide angle fan of spray (say 6" wide at 30cm long) the way you described the lines the nozzle could be putting out more paint at one side than the other.

ye still need to sand everything off though hope this helps ye

[automania]

I give it a bit of a wet n dry before, the primer not loads tho. I used the hardener activator theygave me with th paint.
The gun is very old an tbh I don't know what the knobs do, but the spray was about 3 maybe 4 inch wide from about 12 18 inch. Is this wide enough?
Another thing when I got some runs, i sanded them down, and it did seem a bit elastic and peeled a bit off down to the primer.

I won't be sanding it down, it still looks better than the rest of the car. But I want to know where I went wrong for when I finally
paint the rest.
Cheers again mike.

[muddyoffroader]

its the primer. ye need to rub it down (i find wet best with tiny bit soap) 1000 or 1200 grit just to get it smooth. dont worry about thinly coatied area where the paint shows through just get it so its smooth, clean it, dry it then wipe over with panel wipes. in all honesty 1k paint would be better if ye aint sprayed before just takes a bit longer to dry. apply thin coats either side to side or top to bottom which ever ye prefer but side to side gets it done quicker. lat the 1st go tacky then apply 2nd coat. let it dry then apply next coat and repeat until ye happy with it. if its a bit orange peely look when ye done rub it over with 1200 or more grit paper wet a few weeks after then polish it like hell. give the gun a good cleaning take it apart and clean all the bits, spring, jet ect then spray thinners through it into a rag to save the environment :dance:
bit hard explain how the gun works so i looked for a pic for ye. might be different but all basically do the same thing. as for the width of the fan its all down to the sprayer, if ye new to it and dont want to get loads of runs a wider fan is better.



if ye gun really is knackered just buy a cheap and cheerful gravity fed one from fleabay, if ye only do a panel at a time and not a full car ect ye only need a small hobby type one for around £20.

[eugene]

if you da the panel before the etchin primer then lightly rubbed that down when dry then the primer letting that go off then
you can do top coat and laquer wet  on wet the diffrence in shade maybe were you sprayed it on un even and as always it down to the preperatoin of the job and how good a sprayer the person is

[Range Rover Blues]

You do know 2K is toxic don't you?