How to 'prep' car parts for painting?

[AhmedRSi]

Need a full bootlid and spoiler sprayed (currently in a diff colour)

Trying to save money so thought i'd prep them myself? Could anyone help me out or point me in the right direction? Is it a case of just sanding down the existing paint with wet/dry or what?

 

[Charlie.]

Theres a guide on spraying the spoiler somewhere

 

[Gally]

You should just leave it to the experts mate.

The prep work is the important part.

 

[AhmedRSi]

Yeh been searching and this keeps getting mentioned. Tbh, how bad could you f**k it up? Its just a bit of sanding... right?

 

[Charlie.]

http://www.cliosport.net/forum/showthread.php?t=243967&highlight=spraying

 

[AhmedRSi]

Yeh seen that guide before but thats painting something that hasnt already been painted. My bootlid/spoiler are in a totally different colour so would it be the same process or what?

 

[Charlie.]

Don't know haven't sprayed anything before, assume its just sanding back til you get to the point it needs priming like in the guide

 

[VeinAST]

Just need to key it, make sure it's a nice smooth surface, do a bit of wetsanding and the spray it job done.*

*parts of process removed for simplicity.

 

[AhmedRSi]

Since its only a small area and doesnt meet directly with any other panels (exept the roof/spoiler) i might just try spraying it myself... hmm

Anyway, VeinAST - It should be ok to prep myself then yes? Just careful wetsanding then take it to a bodyshop to spray?

 

[VeinAST]

As long as it's prepped fine then I can't see it being a problem.

Not that big a deal to prep, just getting it all smooth/knobble free etc

Doesn't matter if primer is even etc aslong as it's covered all the areas and there's none of the existing colour showing through

 

[AhmedRSi]

Was going to leave the primer to the bodyshop, how deep should i sand? down to the primer or the bare metal/plastic?

 

[AhmedRSi]

Think im going to have a crack at this once the weather stops raining! Cheers for the advise dudes!

 

[JCC]

Yeh been searching and this keeps getting mentioned. Tbh, how bad could you f**k it up? Its just a bit of sanding... right?

Can f*ck it up very easily, especially with silver. Sand/scotch it with something that's too gritty and you'll see all the scratches below the paint. I've seen "professional" bodyshops get this wrong, so be careful mate. Be aware some places won't touch it if you've already prepped it.

 

[AhmedRSi]

Oh dear, But I have proper wet/dry (think a range of grits as well) paper used it to do my side strips last year, painted them myself too and came out pro! but just not sure how to do something thats already painted.

 

[mickstoke]

what colour is it?

 

[AhmedRSi]

Gris boreil (642) same as your old car mick remember me?

 

[mickstoke]

Gris boreil (642) same as your old car mick remember me?

what colour is the spoiler now thou?

 

[AhmedRSi]

a darker grey

 

[AhmedRSi]

this colour

 

[mickstoke]

It wants rubbing down first with a red scotch pad then either wants about 3 to 4 coats of silver paint on or do it in a white or light grey primer first then flatting down with 1500 or 2000 grit paper before painting in silver.

 

[JCC]

Personally I'd never use red scotch for anything other than applying high build primer. Grey for painting over IMO.

 

[AhmedRSi]

I have the following available

240/600/1200 wet/dry

So was thinking of starting with 240 then 600 then give to bodyshop for primering/painting

 

[s31len]

240 is too rough IMO, no need for it, assuming theres no damage/scratches/filler to flat down?

From what youve got 600 grit (make sure with a block), would be okay.

Woudlnt expect a large saving though on the price, a bodyshop would have it flatted down in no time at all, and any work marks you find in the paint theyll blame your prep

 

[JCC]

and any work marks you find in the paint theyll blame your prep

This is another good point. Seriously matey, I'd wait, save the cash for a bit and get them to do it all. If you really want to give it a go however, 1200 used wet is fine for sanding down for painting. If there's any damage you'll need to go a bit grittier.

 

[mickstoke]

sorry i meant grey thats with working with the 3 different pads every day also have purple

 

[AhmedRSi]

My god i cant be arsed. Just tried sanding on 240 grit for about 10 minutes and you cant tell a difference in the paint, bar a small patch where ive got through to the primer. Im Knackered tbh, feck this im taking it to someone to spray.

 

[AhmedRSi]

a bodyshop would have it flatted down in no time at all

That... has put me off

 

[s31len]

My god i cant be arsed. Just tried sanding on 240 grit for about 10 minutes and you cant tell a difference in the paint, bar a small patch where ive got through to the primer. Im Knackered tbh, feck this im taking it to someone to spray.

you also dont need to go through to primer, just flat the top coat

plus the 240 grit will have scratched deep into the primer.....more work!

 

[AhmedRSi]

Lol ok ok i see, ive been sanding it for a while now on 600 grit and its turned out nice. Just waiting for it to dry then ill go over it all on 1200. Used 240grit for only the problem areas (eg where there were scratches or defects in the original paint)

 

[jack_davey]

once you practice on a few (smaller) parts, you'll know what to do in future