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spray paint

Posted: Wed Apr 04, 2012 6:43 pm
by green123
hello i have sprayed my car in cellelouse paint it looked good when i first did it a few months later the paint has got like craks in it little lines all over the paint work put the paint is still firm on.you cant feel it but u can see the lines and looks terrible could it be a reaction can anybody help me with it cheers

Re: spray paint

Posted: Wed Apr 04, 2012 6:44 pm
by chickenjohn
You have a reaction with a layer below the paint. I'm afraid the best way of dealing with this is to re-paint the car. Either use a bar coat before priming or strip the offending panels to bare metal, etch prime and start again.

Re: spray paint

Posted: Wed Apr 04, 2012 6:46 pm
by PSL184
It's due to the paint shrinking. Flating back may help but the ultimate fix is to take it off and respray it. Prep needs to be better next time....

Re: spray paint

Posted: Wed Apr 04, 2012 7:04 pm
by bmcecosse
And perhaps many thin coats with much drying in between...

Re: spray paint

Posted: Thu Apr 05, 2012 7:21 am
by kennatt
could be reaction but that is usually as soon as you put the paint on,or shrinkage cause by too thick a paint caused by respray after respray then when the pannel expands and contracts in the sun cracks appear. A photo would be a good clue.

Re: spray paint

Posted: Thu Apr 05, 2012 9:35 am
by green123
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Re: spray paint

Posted: Thu Apr 05, 2012 9:36 am
by green123
here is another[frame]Image[/frame]

Re: spray paint

Posted: Thu Apr 05, 2012 8:51 pm
by bmcecosse
Oh dear.... well ALL that needs to come off!

Re: spray paint

Posted: Fri Apr 06, 2012 6:57 am
by green123
what has it done is it paint shrink or a reaction cheers

Re: spray paint

Posted: Fri Apr 06, 2012 7:36 am
by kennatt
looks like shrinkage to me, reaction usually is instant within a few seconds of putting celluy on top of an oil based paint.and its more like a crinkleing,if there such a word,like wavey lines all over.and it normally is only on the very top surface,ie in the celly coat and you can feel the raised edges.If you flat the top coat off gently,just remove the coat you have put on,and you will be able to see if the old top coat is still sound,ie no cracks.If it is sound then its reaction,because shrikage usually goes right through the whole paint to the original primer, the shrinkage starts in the older paint layers. If reaction then either,remove all signs of the crazing,thats the word I was looking for,repaint with an oil based paint,or do the whole area with a barrier primer then celly on top,If you use the barrier don't flat through it or you will get a reaction in that area.If shrinkage...... You need at strip all the paint off to bare metal and start again :o One of the doors on my 55 had this problem,it was a secondhand door I fitted which had been sprayed several times,tried to just flat out the shrinkage and eventually thought I had got rid of it after getting rid of two lots of different respray layers to a sound base, Resprayed.......... yes you get it,cracks came back after six month or so. so bare metal and respray still sound after 5 years.So don't be tempted to do the same. Either way you have a lot of work on your hands.. Good luck with it.

Re: spray paint

Posted: Thu May 17, 2012 6:42 pm
by green123
so i have come to do the paintwork on my car now and i was thinking about doing it in 2 pack stripping it right back to bare metal and starting all over again with 2 pack and a air feed mask and keep giving it breaks so i dont breath any in does any one know if i need to take all the paint of could i use a barrier cote thanks

Re: spray paint

Posted: Thu May 17, 2012 8:42 pm
by tysonn
You're contradicting yourself here.You mentioned taking it back to bare metal which is the only answer I'm afraid.You mention using 2k with an airfed mask but then "giving it breaks so I dont breath it in",well thats what the mask is for.Your choice of paint system is just that,your choice.

Re: spray paint

Posted: Fri May 18, 2012 7:12 am
by kennatt
If that is shrinkage,which it looks like, you will need to go right back to bare metal to be sure it dosn't come back,shrinkage ,in all the times I have seen it,normally goes right through to the primer.Painting ,nowadays, is too expensive to risk a problem in a few months time.

Re: spray paint

Posted: Sat May 19, 2012 8:03 pm
by Dominic
In the days when I was a violin maker, I encountered this several times where under coats of varnish hadn't hardened off enough before the next coat was applied. Could be a similar problem?

Re: spray paint

Posted: Thu May 24, 2012 11:50 pm
by stag36587
Dominic wrote:In the days when I was a violin maker, I encountered this several times where under coats of varnish hadn't hardened off enough before the next coat was applied. Could be a similar problem?

You were a violin maker? Fantastic. I am a cellist - did you ever make one?

Re: spray paint

Posted: Thu May 24, 2012 11:54 pm
by Dominic
Mostly violins and violas, but also made 7 cellos. I have some photos somewhere if you care to PM me your email address