Primer lifting

[Alex.]

Seem to be lots of knowledgeable folk on here, here's my first question.

My Scimitar was professionally resprayed about five years ago, they had to do it twice because the paint blistered soon after the first try. It's now doing the same thing, an I'm wondering what's going on. The blisters start on concave areas, it's as if the paint is shrinking and pulling itself (and a layer of primer) off the primer below.

Suggestions from local bodyshops include water in the GRP which I doubt because the car was low-baked overnight before the painting, and rubbing down between primer coats with too-fine a grit paper.

Any other ideas? I'm going to try repairing the worst of the bad bits but I'm curious about why it's happened.

Thanks

Alex.

 

[fingers99]

What primer was used? My first guess would be that it wasn't correct (for GRP), my second that it wasn't panel wiped correctly, the third that there was water in ant filler used (rubbing down wet, not allowing time to dry).

 

[pedrobedro]

Probably something to do with the fibreglass bodywork. Gelcoat might contain wax or absorb wax from cleaning and polishing during it's lifetime.

 

[Alex.]

Sorry, I've no idea what the primer is, except it's white/light grey.

Don't think there's a problem with the GRP itself as the first layer of primer is well stuck to it, but then the second primer layer is just detaching itself.

 

[malcolm]

Could you post some photos of problem areas - otherwise you'll be getting guesswork.

For my own guess - was cellulose paint used, and are the inside curves where paint is lifting fairly tight? I have some paint lifting on my lovely Renault in the inside corners of swaged features. My interpretation is cellulose isn't all that flexible, and perhaps tightens over time, and I didn't clean up properly after wet sanding and left primer dust in the tight corners leading to poor adhesion.

Though yours blistered on the first try - that's got to help diagnosis.

 

[jaykay]

all the above,but anyones guess.
baking will bring oil/grease/wax to the surface.and if it was'nt clean well after that,who knows.

 

[Alex.]

Some photos as requested-



The screwdriver is lifting a flaky bit of paint.



This is the biggest chip that's come off so far. It's about six inches long and you can see there's a layer of primer on the chip and on the car. (the actual car body has a brownish gelcoat)



And this is the same chip showing how flexible it is! It's about 0.48mm thick if that's relevant. I don't know anything about the paint that was used other than it's base coat and lacquer and some that I was given for touch-up five years ago is still liquid so I'm guessing it's not two-pack??

My hope is that after 5 years everything that's going to come loose has come loose and that redoing the bad bits won't be a total waste of time. Thanks for all your help.

 

[jaykay]

i think i would look at full strip and respray.

 

[Alex.]

I did! Even if I de-trimmed and stripped the paint myself it was still going to be in the £2000 region and that's not an option for me.

 

[jaykay]

the thing to do is get some of that brown packaging selotape,use a good brand.
stick it on your paint,bonnet or doors. rub it well on.pull it off fast. if it takes paint off. then you know you have a adhesion problem.
in fact try several places,low down on panels.

 

[Alex.]

Good idea Jaykay I'll bear it in mind.
I'm beginning to wonder if a good hard emergency stop might drop all the paint on the road!

 

[Robotstar5]

I'm beginning to wonder if a good hard emergency stop might drop all the paint on the road!

Or try driving over a few cattle grids!

 

[joe666]

that to me looks like intercoat adhesion problem who ever sprayed your car never fully cured the primer before painting over it
if you smell it it will stink of thinners
problem is it will all peel off been there myself before,we peeled all the paint off a focus once..
i would either peel it all off or try to feather it back then spot repair it if its only a couple panels

 

[Alex.]

Thanks Joe666, there is certainly a strong smell of something when I pull a sheet off.

At the moment I'm feathering and touching up because I can't afford a real respray.

Alex.

 

[joe666]

are you any where near aberdeen in scotland if so i know someone(my bro) that will help you out if needed ?

 

[Alex.]

Not exactly - I'm in Fife but I go up to Aberdeen fairly regularly.
I think I'm still doing OK so far

 

[danelectro]

looks to me like bad prep. I'm sure if it was water bleeding through you'd get patches, but for paint to come off that clean would indicate (as jaykay said) adhesion probs, which could be bad prep or paint/primer.

think the sticky tape idea is the best place to start.

 

[jaykay]

also being grp body,it would be able to let panelwipe penitrate. if it was panelwipe and sprayed be for it was dry.could of trap solvent under paint.

 

[danelectro]

If it were me I'd strip one section and re do it, see if the problem occurs again.

 

[jaykay]

i agree, ford anglia's used to get that problem on the top underside of back window. where it sloped back.used to be a solvent trap.