Basically I have had some issues trying to paint a spoiler for a friend, im not new to painting ive done a few cars, paint repairs etc but im just not sure whats going on with this spoiler.

It came in a ready to paint primer, so I used 320 da pad discs and went over it by hand, then I panel wiped it and went over with a euro 1k grey primer, let that go off then I guide coated it and wet rubbed it with 800 wet + dry, after this I used ici base coat colour mixed with multi purpose thinners, let that dull off then used a euro 1k lacquer over the top. But as soon it started to go off it sank in places and also when I put it outside to dry off in the warm it started to micro blister in places which has never happened to me before,

This is the worst corner,


Then this is what I found when I removed all my paint and sanded it down further through the primer it came in, its like loads of holes?

 

Probably stupid and I'm no painter but have you used wd40 or something near by......I'm sure you haven't but thought I'd throw that in.....

 

No mate, its not a silicone reaction as that fish eyes the paint, all compressor and lines are clean and it also has a moisture separator fitted

 

could try some acid 8 etch primer?

 

Had something similar on a bike panel I was painting, what ever I did it would react and also couldn't work out what was reacting with what. I flatted it back and then used an isolator then carried on. It worked and got the job done but never did work out why it reacted in the first place.

Just out of interest, your first shot shows the clear over base but the other show something lighter. Are these your primer stages showing the same reaction all throughout the pain job?

 

No the first pic is after I painted it, the lower pics are of the spoiler completely sanded back down and what I found under the factory primer.

 

Only option I would take in that situation is to completely remove all paint and start again with a plastic primer, high build primer then base and clear. I would assume what's happened is that the existing primer, your high build and base and clear are just not compatible with each other.

 

just looks like pin holes in the spoiler from when its moulded hard t tell from picture,us a good bar coat an start again

 

If it was me I would bake the spoiler off before applying any paints to it, as it could be the mould of the spoiler is not fully cured then add a barrier coat, something like bar coat then flat this off. Then on with the base and clear coat.
I know you didn't bake it last time and I wouldn't bake it after you have finished painting it just let it air dry.
Oh I am a painter of 17years experience, and have had this sort of thing happen to me before on an aftermarket spoiler as well.

 

Thanks for your replies, I havnt got the facilities to bake the spoiler beforehand so all I can really do is see if my paint suppliers do the bar coat, is this stuff straight out of the gun ? No mixing with anything ?

 

Yes give it a good stir and straight out the tin no hardener or thinners to be added.
Hope this helps.

 

Cheers, at least with using 2k high build it goes off concrete and doesn't allow anything back through. I should if just used it in the first place it was the paint store that said to use the 1k high build as no mixing etc, should of just stuck to what I know.

 

don't bake the spoiler it would warp ,just bar coat straight out the gun and do not sand it 2k primer over it after its set for 24hours