Practically Classics Forum

Morning all

If anyone has any ideas about the following I will be eternally grateful!!! 5 years ago we resprayed my car hen over the course of a series of months and years the paint 'crazed' leaving a cracked appearance on all horizontal surfaces it slowly got worse and worse until it looked like orange peel but not on surfaces which were vertical. we though it could be damp which had caused it as we sprayed it outside.

Last night after 2 days of sanding and going over the car with wet and dry etc we put the first coat of primer on and unbelievably the pain cracked again leaving lines as if the primer wouldn't take to the prepped coat underneath, but again it only cracked in certain areas.

Has anyone had this before? Does anyone know what causes it and and what can be done to stop it happening as we don't want to go ahead with a top coat as it will simply crack again.

If anyone has any ideas we would be very grateful. Cheers all

What kind of paint are you using, what kind of paint was on there originally, did you remove it all or just rough it up, what compounds or chemicals did you use to remove/roughen the surface, what manner of construction is the car (steel, aluminium, fibreglass, grp, other...)

Sounds like the original paint hasn't been properly removed & is reacting with whatever you're trying to spray on top, but the more detail you can provide the clearer the solution will become.

If its only cracking in certain areas it might suggest contaminants on the primer coats ie oily hand marks which were not cleaned properly prior to the application of the top coat. Another possibility is a variance in the primer used or too thick an application. I'm sure there are lots of other possibilities.

Hello There

Splitting when paint is first applied is usually down to contamination. On GRP this is caused when the paint cannot fill splits or deep scratches. If it is too cold, you can get the same problem, but usually because the paint has been laid on too thick too quick.

Splitting or cracking when the paint is older is usually down to too much paint build up.

It may be worth reading This Thread over again.

Two heads are better than one, etc. Unless of course you're someone who builds Lancia V4s in which case feel free to ignore that comment.

I bought my 1982 Daimler Soveriegn in 2007 and it looked gorgeous apart from some isolated areas of crazing, over the forth coming years it got to the stage that I could peel or flick large chunks of paint off, last year I decided that I would bare metal it and respray it, albeit outside, now just over 12months from starting I now have a car that is the same colour all over and it's original colour manufacturerd colour.

My car had had in it's past had at least 8 resprays because i could count them by examining the paint flakes, the thing that surprised me was it actually crazed right down through the original paint and left tell tale rust veins on the bare metal, I used paint stripper to remove the paint layer's. A Starchem product that saved many hours or hard work.

My advice would be use copious quantities of panel wipe, wipe it once with a cloth then bin it, wipe it again with another and bin it then wipe it again before applying any paint over a previous coat, even after rubbing down with wet and dry 'wet'. I have done this since a couple of false starts and haven't had any problems since.

Mr M Thaddeous replied to many of my post's and I can only say he is a valuable souce of expertise.