painting over old primer and factory paint

[AussieZed]

Hi folks,

 

I have a query about parts that have been in primer for some time. I have bought a bonnet and some doors that have been stripped back and primed for who knows how long. I hear these stories about primer sucking up water and messing up later paint jobs - is that true? Do I have to go back to steel??

 

A second question that I am sure I know the answer to - but anyway. The factory paint on the roof and rear quarters of my car is pretty much immaculate. You do hear of people painting over factory paint, but I would guess it isn't advisable .... advice??

 

While I'm on the topic ... any recommendations for a panel beater/painter in the east or south east of Melbourne??

 

Cheers, AussieZed

[Sirpent]

Hi

 

It depends on what type of primer it is.

 

Both modern 2Pak Hi-Fill and even acrylic primers are designed to be wet rubbed and do not usually allow moisture to penetrate throgh, however if it is a epoxy based primer then yes moisture penitration is always a posibility.

 

Wet rubbed primers give off a particular scent, a trained nose would quicly identify what you have on your panels.

 

Regardless of that however, this is a trick or treat situation, you just dont know how the panels have been prepped and whether the primer has actually had the correct base material laid down prior to its application, i.e. Etch primer for instance.

 

It would be safer to take the panels back to metal rather than risk fowling up a paint job.

 

On the point of the factory finish panels, these are a low baked proposition, as long as there isnt any sign of crows feet (radiating cracks) humidity blisters (which look like minute uniform bubles) or silcon contamination which look life minute depressions or craters) then wet rubbibg these panels back with 800 grit wet and dry and re-applying a finish directly over them is ok, however if you are using acrylic over these enamel finishes, you must be carefull not top lay down extremely wet layers first as you will end up with solvent burn and a nasty reaction between the 2 paint types.

 

Cheers

 

John

[AussieZed]

Great info!! Thanks a lot.

 

AussieZed

[260Coupe]

Hi folks,

 

I have a query about parts that have been in primer for some time. I have bought a bonnet and some doors that have been stripped back and primed for who knows how long. I hear these stories about primer sucking up water and messing up later paint jobs - is that true? Do I have to go back to steel??

 

A second question that I am sure I know the answer to - but anyway. The factory paint on the roof and rear quarters of my car is pretty much immaculate. You do hear of people painting over factory paint, but I would guess it isn't advisable .... advice??

 

While I'm on the topic ... any recommendations for a panel beater/painter in the east or south east of Melbourne??

 

Cheers, AussieZed

 

 

You could try Paul Rankin at Rankins Restorations in Bayswater.............did a great job on my Zed and in reasonably priced

 

03- 9729 0622

 

[drifta1600]

or silcon contamination which look life minute depressions or craters)

 

 

Oh i hate silicone! i sand and polish timber floors and somtimes when people put fresh silicon around a windowm the fumes react to the floor coatings and leave minute depressions or craters :-)

Yer if you go over some old paint do a few realy light coats first then you wont get a reaction between the two paint :-) with crows feet, you can sand them back to the undercoat and fill it up with spray puty, then paint over it, (ive never had it com back)

[AussieZed]

Howdy,

 

Thanks for the advice all ... too bad you're not in Melbourne drifta1600 .... there's two jobs I am afraid of stuffing up ... painting the Z and refinishing our timber floors!!

 

I am keen to learn about how to paint but I don't want to practise on the car I always promised myself (the Z obviously), and it seems like the investment in a gun and a worthwhile compressor would be a bit silly for one car.

 

Are there any painters in the club? Would be more than happy to pay the going rate if they were willing to have me hovering around in the background helping out and generally getting in the way.

 

Message me if anyone is keen and capable ...

 

Ross

[reverendzed]

Sorry Drifta, but if you use your method over 'crows feet' it will ALWAYS come back! why? because there has been a breakdown in the paint which has penetrated at least to some point the substrate.  If you have any compromise in the paint at any level from etch upward the only 'real' way to fix it is strip and start again.

Rev.

[Sirpent]

I agree with Rev 101%,

 

Commonly crows feet is a result of poor previous paint surface preperation leading to the upper surface expanding and contracting and losing adhesion with the sub surface it was laid over.

 

I have seen some beaters years ago basically cut back paint work with machine cutting compound and then paint straigh over the top of it, this always led to cros feet down the track.

 

It isnt that common on OEM factory paint, however I have seen a number of U.S. cars such as the Probes and Mustangs of the late 90's suffer this from the factory.

 

The only way to remedy crows feet as mentioned in the first paragraph is to wet rub the upper paint surface all the way back to the substrate, I have used a soft block and literally taken an entire panel back wet and dry this way to the original finish underneath.

 

If its in the OEM paintwork, it's bare metal time Im sorry to say.

 

Cheers

 

John

[AussieZed]

LOL Salty ... I like that ...

 

I suspect that is what most people would think.... I'm paid to teach people how to do stuff and I STILL complain about them being underfoot.

 

No sign of crows feet on my factory paint but I am swaying more and more towards just ripping it all off ... my hatch, doors and bonnet need stripping back anyway .... after that's done the roof and back quards just won't look like that much more....

 

R.