What sort of plague is this...

[Discseven]

The surface you’re looking at was painted about 7 years ago. The finish was excellent all around when the car was completed back then.

Over time, welting has appeared in varying degrees in limited areas. The front hood has it the worst. The rear hood comes in second place. The rear fender flairs in third.

Front fenders as well as the doors and remaining parts have absolutely none of this. All these parts look excellent.

I’ve spoken with the body shop that painted the car to see about getting this corrected.

They’ll get the front hood as a test.

Before delivering the hood…

I’d like to know what I’m dealing with and if you have any recommendations.

(The body shop suggested I replace the hood. Not happening because… while that might solve the hood problem, there’s still the issue of the rear hood and rear fenders --- the point of doing the front hood is to see if they can correct the problem. If so, they can treat the other parts to the same procedure.)

Various views from front hood:

[shadowjack1]

Before the paint job. Was the car involved in a fire? I often wondered if a fire would affect the metal in the long run. THis is Just awag.

[twistoffat]

that looks like the dreaded "Orange Peel". Its usually caused by paint drying too quickly or even when its spread on too thickly. I´ve only ever seen it on fresh paint jobs that have been botched and know its more common with new water based paints. First time I´ve seen it appear on a 7 year old paint job. The cure on a overly thick paint job was patience and wet sanding. My guess that at 7 years some sort of chemical process is going on between the paint and the surface of the metal which could mean the surface wasn´t preped properly before painting

[widgeon13]

How was the surface prepared before the paint was applied. Was it primed or just paint over the original color after sanding? Or was the entire car taken down to bare metal? Is the condition apparent all over these surfaces or just in some areas?

If it was not taken down to bare metal could it be a reaction between two different types of paint? Acrylic vs enamel. Also just guessing.

[Laneco]

Post this in the paint/bodywork forum - Freddie Hernandez is THE man (plus he's a nice guy who rides mountain bikes).

I see alot of orange peel, and it's generally evident pretty quick after the paint job - doesn't mysteriously pop up 7 years later. What I think you are seeing here is coming from the bottom up, meaning that there is an issue between the metal and the base layer.

Check with Freddie - he can probably tell you exactly what it is. Would be helpful to know the year of the car (galvanized or non), fully stripped or painted over the original material, and the type of paint used.

angela

[john walker's workshop]

looks like rust is forming. pop one of the zits and see. needs to be redone anyway.

[Discseven]

FIRE

No fire that I know of. The inside of the hood looks original. But the question does point to something...

I did get a used hood for the last paint project because it was cheaper than fixing the dings and rust in the existing hood. The fact that there's a replacement hood and the same plague is occurring on metal that was previously with the car... this says something.

PREP

I'm candidly not sure what was done in regards to prep work. The body shop does all kinds of sport cars from Lambos to VWs to Porsches. And they do both new and classic projects so they have experience with "old metal." The work I saw while looking over the projects they had in-house was all good. They also came with a recommendation from a good friend. When I discussed painting the car with the manager, I trusted they knew what they were doing. Perhaps not. I'm willing to give them a chance to make it right.

This time, I'll definitely want to see the hood when stripped.

[widgeon13]

Originally Posted by john walker's workshop

looks like rust is forming. pop one of the zits and see. needs to be redone anyway.

my thought as well but I didn't want to say it.

[89Coupe]

I paint a bit. Looks like adhesion issues. Poor paint jobs don't always look poor when completed, but over time the lack of bond between the paints becomes apparent. I have had this happen once when I painted a customers piece that brought to me pre-primed. Over time his primer lost adhesion. It is clear that the metallic base is separating from the primer or primer separating from the substrate possibly due to oxidation. Hence the mini-mountain/bubbly look in the paint. Metallics sprayed on poorly sanded primers can look like this, too. Sometimes paint shops will sand the primer and let the car sit for a while before painting, causing a hard film to form on the surface of the primer and thus, poor adhesion. This sucks because the customer gets a nasty surprise as early as a few months following painting, or sometimes a few years down the road. Finishing is an art, prep and staying within recommended paint manufacturers time frames for applying subsequent coats is paramount to a good/long lasting paint job.

[Charles Freeborn]

That looks like what on my car turned out to be rust.

[dfhtrhjn]

Looks like what 89Coupe said. There are cleaners for properly prepping a surface and right primers have to be matched with the type of paint for best adhesion. I've run into this a couple times at home before I got the process right. Any of the things he mentioned can cause that look.

[HawgRyder]

When I first got my car...the paint was terrible.
So...I started sanding down to primer to get it ready for a re-shoot.
I accidently went a little deep in some areas and discovered 2 layers of primer.
The red primer was over top of a grey primer (on bare metal).
The problem was...the grey primer had gotten wet...and rust had started.
The previous painter had just shot red primer over top of the bad layer...then top coated it.
If I had not found the rusty spots (looked like measels all over the car) I would have had it fall apart in no time at all.
Shows that previous owners can leave you with time bombs you don't expect to find!
Bob

[86 911 Targa]

Front condenser blower motor fires were not uncommon.

[wachuko]

Originally Posted by HawgRyder

When I first got my car...the paint was terrible.
So...I started sanding down to primer to get it ready for a re-shoot.
I accidently went a little deep in some areas and discovered 2 layers of primer.
The red primer was over top of a grey primer (on bare metal).
The problem was...the grey primer had gotten wet...and rust had started.
The previous painter had just shot red primer over top of the bad layer...then top coated it.
If I had not found the rusty spots (looked like measels all over the car) I would have had it fall apart in no time at all.
Shows that previous owners can leave you with time bombs you don't expect to find!
Bob

You don't have to tell me that!! The person working my car is taking the car down to metal because he found several layers of crap when he started working the car. He was not going to risk the pain job to be ruined by someone else lousy work.

On the positive, he tells me that it will be lighter There was liberal use of a red putty all over the car, yikes!

[Discseven]

TY guys for all the input...

I just completed my discussion with the manager at the body shop that painted this hood 7 years ago.

Whatever is happening under the paint (I'm concluding internal rusting), the hood will be taken down to bare metal. If the metal's condition is suitable for repainting, we'll proceed accordingly. If not, I'll be looking for a used hood.

I found some informative links with presentations by Freddie Hernandez in the Paint & Body forum. Here are those links:

1.

Paint Stripping 101


2.

Metal Conditioning And Epoxy Priming 101


3.

Bondo Work And Primer Application 101


4.

Final Sanding and Painting 101

[mfyoung1086]

Originally Posted by 89Coupe

I paint a bit. Looks like adhesion issues. Poor paint jobs don't always look poor when completed, but over time the lack of bond between the paints becomes apparent. I have had this happen once when I painted a customers piece that brought to me pre-primed. Over time his primer lost adhesion. It is clear that the metallic base is separating from the primer or primer separating from the substrate possibly due to oxidation. Hence the mini-mountain/bubbly look in the paint. Metallics sprayed on poorly sanded primers can look like this, too. Sometimes paint shops will sand the primer and let the car sit for a while before painting, causing a hard film to form on the surface of the primer and thus, poor adhesion. This sucks because the customer gets a nasty surprise as early as a few months following painting, or sometimes a few years down the road. Finishing is an art, prep and staying within recommended paint manufacturers time frames for applying subsequent coats is paramount to a good/long lasting paint job.

+1 looks like poor prep work, although I've also soon pool chemicals spilled do this as well (but since you're not cleaning pools I don't believe that would be the case