Hi. I'm relatively new to painting cars with only two under my belt both with acrylic lacquer.

I wasn't a fan of that paint and I'm looking to use a urethane two pack paint for base and clear coats this time around. Please add any advise on that if you have any tips.

I have a old beat up ute (utility, pick-up) that has severe cracks in the paint. I have included a toothpick in all photos to indicate size.
I don't want a perfect finish, in fact just something to get the car by for another 5 years will do. I don't want it cracking soon after this paint job.

Left door, small cracks
http://phizinza.com/images/door_small_cracks.jpg

Left door, large cracks
http://phizinza.com/images/door_large_cracks.jpg

Left pillar, large cracks
http://phizinza.com/images/pillar_sande ... cracks.jpg

Roof, small cracks sanded over; about half thickness of paint taken off
http://phizinza.com/images/roof_sanded_small_cracks.jpg

I've just been using 80 grit on a D/A so far.
On the pillar you can see many layers of paint, it actually goes like this from what I can tell: Metal > factory Primer > factory Red > grey primer > yellow primer > red > grey primer > red. Other parts such as half of the roof go: Metal > primer > red > primer > red. Other half of the roof: Metal > primer > red. The picture of the roof is of the original red as there is only one primer under it. That primer doesn't seem to be cracked, but it's so thing I have been sanding straight through it.
Either when it was sprayed they didn't do a clear or the clear has completely worn away.

What I would like to know, is there a way I can sand less and still get a finish that won't crack for at least 5 years? At this stage I have sanded for 2 hours and I've done less then 5% of the sanding on the car.

I read that there is a product called Epoxy Sealer Primer I think which will "lock down" the paint under and stop cracking coming through to the new paint. Is there such a thing? If so, do you think I could paint over those cracks on the roof that I've sanded? Obviously the larger cracks will need to be sanded out, or can they be filled with spray filler?

And if I want to two pack the base/top and clear coats, what primers should I use on existing paint and bare metal to prep it?

Thanks for taking the time to read this and respond.

That paint is being stretched and cracking due to differences in thermal expansion coefficient between the layers, and the fact that it was put on very thick. No matter what you fill it with it will continue to move around and crack over time.

Best bet is to strip it and when it is that miserable to sand then my choice is to break out the gallon(s) of paint stripper...

Where the large cracks were I decided to take it back to steel using a blue Josco stripping disc on the grinder.

Here is where I took it back. Turns out there was a 4mm thick layer of cracking bog under the paint with surface rust at the bottom of some of the cracks. The bog had 3 layers of primer and red on too of it so it has been resprayed a few times (probably trying to fix the cracks) under the bog it had hail damage... Not sure why they used such a thick layer of bog, but I'll patch it up a bit and respray the car. For the small cracks I decided to just fill them and not worry to much. Its only a 27yo pick up that I'll be using rough anyhow.

Phizinza wrote:Hi. I'm relatively new to painting cars with only two under my belt both with acrylic lacquer.

I read that there is a product called Epoxy Sealer Primer I think which will "lock down" the paint under and stop cracking coming through to the new paint. Is there such a thing? If so, do you think I could paint over those cracks on the roof that I've sanded? Obviously the larger cracks will need to be sanded out, or can they be filled with spray filler?

No and no. I still like lacquer but a lot of people get fooled by the quick flash times so they spray too many coats too quickly. The thinner in that first coat is still trying to cure while more is being added. The 'crazing' from buildup is commonly seen where the painter changed directions without going beyond the panel.

It's time to sand that down to bare metal.