why is my paint job ****?

[Yeomans22]

ive been re painting my engine bay, ready for the new engine but when i paint, the paint is cracking?

 

 

do u think its becasue its to cold to paint?

 

Paul.

[bazbiker]

Looks like it's reacting to whatever you have painted on top of!

[Trevmk3]

what did you do to prep the surface?

[Yeomans22]

wet and dry

[Trevmk3]

did you degrease the surface well as any oil residue will affect it as will alot of other substances, im not sure what grade paper you need to key the surface myself. were you painting onto an already painted surface?

[Yeomans22]

i painted it last year, but blew the engine up so im doing a better job, at leat i planned too, whats best to de grease it with, i've got some paint prep wipes,

 

i sanded it back quite a bit, im using halfords sprays like i did last year as well.

[steve mk2]

you can prep paint straight on top with 500 grade paper and grey scotch flat primer with 500 too, any heavier grit will show scratches and look bad, must make sur car i degreased thoroughly and free from any moisture atal preferably warm

[Trevmk3]

not too sure myself mate as i havnt done mine yet myself and i borrowed some of the stuff the painter at work uses before spraying machine panels

[ASBO CAPRI]

Could be traces of silicone on the preped surface. Any tiny trace of silicone will make your paint pickle like that

[caprinerd]

i had this problem i put one kind of paint on and when i changer the colour to a different one the paint cracked and it was due to me using a different kind of paint it reacted but it would let me do it the other way round though

[Retro-gone.]

you needed to use etch primer 1st mate. it stops all the reactions.

[Fishtailparka]

Panelwipe from an auto factor is what you use to degrease before painting. I expect it's on ebay too.

2k filler primer will cover most things without reacting, and gives a good base for paint.

I find etch reacts with most paints in some way or other. It's an acid, so not surprising. Etch is really only for bare metal. Rub it back to bare metal and etch is the best way, but not usually necessary unless it's rusty.

[Retro-gone.]

ah i thought gone back to bare metal, im doin my engine bay and what ive done is flat back the original paint or take back to bare metal whee needed, wipe the whole lot down with panelwipe, then 2 good coats of brush on red oxide primer, flattened that down and this aft im giving it a good seeing to with 2K primer,

heres the pics.

http://www.oldskoolford.co.uk/phpBB2/vi ... hp?t=85659

[steve mk2]

if its reacting just key it up with some red scotch and give it a good two coats of waterbased primer then u wil not get any reaction atal

[GT_lenny]

Flat it back and give it some "barcote" you can paint over grease with that stuff

[Yeomans22]

thanks everyone

 

i painted it with some filler primer yesterday and most of the cracking has stopped, there was just a couple of areas that have reacted so if i take them to bare metal that should stop it?

 

also when putting the top colour on should i do it in very light coats of paint?

[steve mk2]

if ure stil worried about reacting do 2 light dust coats to seal it then two full coats and tht should do ya and keep it warm wer ure spraying

[Yeomans22]

thanks everyone i've painted it now, still needs a couple more coats but it looks great, nothing better than doing something yourself, keep ur money in your own pocket

 

any rust was treated with rust remedy,

 

2-3 coats of zinc primer

2-3 coats of filler primer

1 dusting of grey primer,

so far 2-3 coats of green will do a couple more before about 2-3 coats of clear

 

[Rick]

the solvent in the new paint is softening the paint underneath,

 

the top dries before the bottom and it causes it to crack.

 

what you wanna do is dust the first few coats on very lightly and warm the surface before doin it

 

warmth is 50% of the battle in this weather