Paint ... etch primer?

[Tornado]

What am I seeing here? First pic is a flake of paint, which is a different colour underneath. Does that mean it's top coat and primer combined?
Second pic seems to show top coat, some primer and some galvanised metal?
So, would etch primer be the best bet? I have some top coat in the correct colour, just waiting for better weather. Any day now...

 

[Deleted member 31521]

For metal surface sticking you want an acid etch primer.
The image you show looks like either water has gotten under the coat of primer and lifted the paint or from a point of view of a novice the paint flake has been caused by a poor past repair.
This repair in that case could have been rushed or not correctly applied.
Maybe the wrong primer for the job.
But looks to be etch primer and a top coat.
Really depends on what your seeing tho is the original paint flake or repaired paint work done as DIY or other type such as spray can.
Im sure you will be able to see if there's sign of a previous spray or repair if its just one area and not whole panel.

Best for bare metal use etch get a good quality product to make your repair and do this in a good temperature and dry wether.
Other cheap primers may or may not adhere well to bare metal surfaces.
I've used etch for my alloy wheels because I had paint flakes once over but this I would say was because of application in cold temps drying times between coats are also important to get the paint to adhere properly and not leave patches unseen that did not dry properly.
Good sunshine or a heat device to get desired temp after applying paint coats is crucial for a lasting finish.

I used upol for both coats its a good idea also to stick with same brand for prime and top coat to avoid incompatible reactions in the paint layers.

One question is this in the bonnet area or near to place of heat source such as near by the engine bay.?
As high heat could over time cause separation of coats and metals.

Hope this helps somewhat

 

[Tornado]

Thanks for the reply. The car's pre-history is unknown, there is some evidence of bodgery. Bought from a garage that does water based spraying, when I went to view it the bloke had a power washer at it before I could stop him. There were a few little spots of paint off, but by the time I got it home and hose+and+brush washed it, a lot more paint had lifted. I'd say if I tried scraping, the whole roof would be bare.
I have 2 rattle cans of the correct colour and a clear coat, so I guess the way forward is a light fine sanding without removing too much more paint, apply some acid etch then colour coat. (I have a can of a different but similar brightness colour, any point using that on top of primer for a thicker coat?)
I'm not expecting perfection, just to make it a bit more presentable, and stop it getting worse.

 

[Deleted member 31521]

Yeah you will need to sand the area back and go well into the area of good paint maybe an inch or so it might make it look like you made it worse.
But your main aim would be to get a nice flat coating and at the sanded joins to the original paint that is left the tricky part is feathering the two so it's less visible.
If however you just want to cover it over and ain't bothered about paint transitions.
Probably will be alot less trouble for you.
I suggest doing it as best you can but only expect to protect bare metal.
You can always return to that later and tidy it up.
Also when it's done you are able to sand back with 1000 grit upwards to remove fisheye.
If the area is really small it might not be so noticeably bad.
Consider that when looking from a set amount of feet away if you can get it to not standout at 6 feet you done a pretty acceptable job for DIY.

I have not done any bodywork paint yet but my task area is rear wheel arch that will need doing eventually and also behind rear headlight didn't look too dandy.
And since it's hidden behind something is not a good reason to ignore because that's where the troubles will start if left to develop further.
My only items so far have been touch ups on bonnet and a few scratches at rear quarter panel etc.
My main work was the wheels definitely not perfect but don't look terrible from a few feet.
Don't forget when you do start this task saftey top of list (wear a good mask and goggles gloves are also handy)

If you use the colour that's near to the cars original it might not look good I would not use it personally but one may argue that the original code will also standout a shade brighter also but will eventually blend alot better.
It looks metallic to me also. As I can see silver flakes in the paint