DIY rattle can on already painted metal.

[Cads]

As a little project I wish to change the colour of an already painted piece of metal on my Clio.

I'm aware there are some professional body shop guys on here as well as a sea of accomplished amateur's. I'm sure I've seen a thread on here with the process but I cant for the life of me find it and have researched the job as best I can and simply wish to check my understanding of the process.

1. Key the existing surface using scuff pad or scotchbrite to remove the sheen. There's no rust or lose paint to be concerned with.
2. Clean using Acetone and a lint free cloth. Will white spirit do?? Or any other alternatives to Acetone.
3. Prime. Is this necessary if the surface was already painted and has been prepared correctly??
4. Paint the colour.
5. Lacquer and leave to set.
6. Stand back and admire handy work/wonder what the f**k went wrong.

Anything I've missed or should/should not do??

 

[frayz]

Have a go hero here mate.

I’d say priming is deffo worth it and let the primer cure fully.
Lightly flat the primer back with some 1500/2000 set dry and before you paint your top colour. Makes for a better finish as you’ll sand any ridges left in the primer.

What part is it youre painting

 

[plenty]

It’s never as easy as it looks in the videos.

Patience and multiple light coats are key, to avoid paint runs due to spraying too close or too long.

I also consistently find orange peel in the lacquer requiring wet sanding to flatten, which is harder and more time-consuming than the painting itself.

 

[Cads]

Have a go hero here mate.

I’d say priming is deffo worth it and let the primer cure fully.
Lightly flat the primer back with some 1500/2000 set dry and before you paint your top colour. Makes for a better finish as you’ll sand any ridges left in the primer.

What part is it youre painting

Mate, I’ve read your threads on here and PH. You are too modest.

I’ve made a lockdown based purchase of @plenty strut brace they were selling.
And while I’m fully aware it will do nothing for the handling and actually only increase the weight of the car in the standard black paint. Once painted French Racing Blue it’ll look cool and give me and extra 5bhp across the rev range.

 

[frayz]

Mate, I’ve read your threads on here and PH. You are too modest.

I’ve made a lockdown based purchase of @plenty strut brace they were selling.
And while I’m fully aware it will do nothing for the handling and actually only increase the weight of the car in the standard black paint. Once painted French Racing Blue it’ll look cool and give me and extra 5bhp across the rev range.

5bhp at least, probably 10 in RB

 

[R3k1355]

It's all in the prep.

Don't go mad with the scotchbrite, you want a good key but if you press too hard you'll leave scratches that will show through.
You'll need to hang the strutbrace up to spray it properly.

 

[Cads]

It's all in the prep.

Don't go mad with the scotchbrite, you want a good key but if you press too hard you'll leave scratches that will show through.
You'll need to hang the strutbrace up to spray it properly.

Cheers mate. Good advice. I’ve worked out I can hang it nicely from the garage roof.

In terms of cleaning, other than acetone, what else will remove grease etc and provide the cleanest surface with which to prime?

 

[frayz]

Cheers mate. Good advice. I’ve worked out I can hang it nicely from the garage roof.

In terms of cleaning, other than acetone, what else will remove grease etc and provide the cleanest surface with which to prime?

Thinners, brake cleaner, IPA.

 

[obcuz]

Don't use white spirit

I've used pure alcohol (NOT gin etc) for cleaning, doesn't leave residue.

 

[Steven103]

multiple light coats are key

This times a million, particularly when painting a tube which has no flat surfaces so the paint always wants to run somewhere.

 

[mk1mark]

I've just done exactly this on the rear quarter of my bumper. I flatted the existing damaged paint and then painted directly on top of the existing silver, added 4 coats of lacquer and now it's dried into a perfect colour match.

But...it's completely missing it's shine. The surface is perfectly even, but rough to say the least.

Should I wet flat the top surface, or maybe use T-cut?

 

[Cads]

Funny you should say this. Having read the advice, combined with the research I’d already done I think I’ll let a body shop do it.
The car will be having some bodywork done in the next few months anyway and I’ll never be 100% happy with a DIY finish.

 

[plenty]

Should I wet flat the top surface, or maybe use T-cut?

Yes the spray pattern from rattle cans is much finer than from professional spraying equipment, hence the orange peel.

Use wet and dry paper to wet sand starting with 800 or 1,000, then 2,000 then finally 3,000. Then use rubbing compound like T-Cut for the final finish.

Takes a lot of elbow grease by hand, but you can use a polisher or drill to speed up with sanding attachments and discs.

 

[R3k1355]

I wouldn't start a wet sand at 800, start at 2000.

You can always go to a rougher grit if the one you start with isn't right, but if you start off too rough you can't go back.