Unknown Bubbling in paint

0

04VetteZ06

New member
Joined
Jun 26, 2020
Messages
8
Reaction score
0
Hi Mike,

First time poster, though i use to few your tutorials and facebook constantly. I have noticed an issue on the roof of of my Corvette with abnormal bubbling.

My car has been garage kept and rarely driven. I try to keep it waxed at a minimum of once a year. Recently I moved and had more space to do a more thorough job.

I started by using Chemical Guys Waterless Car Wash as i had just washed the car several days prior. As I had some scratches on the roof and swirls I used Meguires Detailer Correction Compound kit i purchased from your store a year or so ago. I followed the instruction for light correction by using the supplied DMF disc pad on a porter cable orbital buffer. to help with lubrication i utilized Griots Garage detail spray as it was the only remaining detailer I had left at the time. Applied a small amount and did 2-3 light pressure passes on setting 3. After wiping off the compound I then used Zaino Z2 as the final coat. a day or so after I went out to my car to double check something and noticed these bubbles exclusively on the roof. I am not sure if this was previously there and possibly etching by bird poop. I dont think its water reacting with paint from underneath. Maybe its a chemical reaction from the mixture of products? It appears nowhere else on the car.

Hopefully someone wiser then myself has answers.

Thanks in advance.

View attachment 70017






0
 
By chance has it been repainted? In my experience as a painter it looks like solvent pop. Basically the paint cured too fast on top before everything could gas out properly.

If not that, some unknown aggressive chemical misted or was on the bottom of something that got set on top. It's hard to tell.
 
Spikey Mike said:
By chance has it been repainted? In my experience as a painter it looks like solvent pop. Basically the paint cured too fast on top before everything could gas out properly.

If not that, some unknown aggressive chemical misted or was on the bottom of something that got set on top. It's hard to tell.
Click to expand...


To the best of my knowledge it has not been repainted, then again I am the 5th owner so its always possible. Why I never noticed it before is beyond me. Is there anyway to correct this or are we looking at repaint in the future? Also would using a mixture of products designed for car care cause a reaction of this sort? I only ask, because as stated in the post there was a mixture of manufacturers.
 
Not in my experience. The products you used are all designed for the exterior treatment of paint/vehicles so they should all be chemically safe with one another. As for fixing it, if it is solvent pop, you are looking at a repaint. If the master Mike Phillips chimes in, he may have a trick to improve the appearance.
 
04VetteZ06 said:
Hi Mike,

First time poster, though i use to few your tutorials and facebook constantly.
Click to expand...

Welcome to AutogeekOnline! :welcome:




04VetteZ06 said:
I have noticed an issue on the roof of of my Corvette with abnormal bubbling.
Click to expand...


Here's your picture in a way it's easier for all to see.

70017d1593379936-unknown-bubbling-paint-unnamed-5-jpg


My car has been garage kept and rarely driven. I try to keep it waxed at a minimum of once a year. Recently I moved and had more space to do a more thorough job.




04VetteZ06 said:
I started by using Chemical Guys Waterless Car Wash as i had just washed the car several days prior. As I had some scratches on the roof and swirls I used Meguires Detailer Correction Compound kit i purchased from your store a year or so ago. I followed the instruction for light correction by using the supplied DMF disc pad on a porter cable orbital buffer. to help with lubrication i utilized Griots Garage detail spray as it was the only remaining detailer I had left at the time.

Applied a small amount and did 2-3 light pressure passes on setting 3. After wiping off the compound I then used Zaino Z2 as the final coat. a day or so after I went out to my car to double check something and noticed these bubbles exclusively on the roof.

I am not sure if this was previously there and possibly etching by bird poop.

I don't think its water reacting with paint from underneath. Maybe its a chemical reaction from the mixture of products? It appears nowhere else on the car.

Hopefully someone wiser then myself has answers.

Thanks in advance.
Click to expand...


The only time I've seen defects like shown in your pictures is from something that has gone wrong during a repaint.

Those look like tiny bubbles that have come up from under the paint.


The chemicals you use are all completely safe for paint so I don't see how moving them over the surface via wiping or machine buffing could cause defects with this appearance.


Has the car ever been re-painted?



:)




[/QUOTE]
 
Spikey Mike said:
By chance has it been repainted? In my experience as a painter it looks like solvent pop.

Basically the paint cured too fast on top before everything could gas out properly.

If not that, some unknown aggressive chemical misted or was on the bottom of something that got set on top. It's hard to tell.
Click to expand...


I agree with all of the above. After pulling up the full size version of the picture and looking at it - my brain instantly thought solvent pop and that's a fresh paint or re-paint issue, not a factory paint issue.


EXCEPT - the defects in the picture look like they are bubbles in the paint.



In my article below that shows solvent pop, they look more like bubbles or voids IN the paint, not on the paint? Here's my article on this topic,

Solvent Popping in Fresh Paint


After inspecting the brand new paint job on the 1928 Model A out in the garage I found at least one place with signs of solvent popping.

Solvent popping is when the reducer, (solvent), which is used to thin the paint to make it sprayable in a paint gun is changing from a liquid to a gas. As this change takes place, the solvent tries to escape and pops through the top film of paint leaving a tiny little crater or what looks like a pin hole.

At least that's the nutshell explanation.


Here's a couple pictures I took to show solvent popping. It is located just above the opening to the rumble seat on this Model A.

Solvent_Popping_in_Paint_001.jpg


Solvent_Popping_in_Paint_002.jpg



Solvent_Popping_in_Paint_002c.jpg



For reference, it's just above the handle you see on the top of the rumble seat in the back of the car here,

1928_Model_A_Coupe_010.jpg







:)
 
I am far from an expert on this, but Corvettes are fiberglass, and I worked on boats for over 30 years.

Just my first thought, but I have seen this exact phenomenon on painted fiberglass that was overheated by rotary polishing.

I am not familiar with the Meg's Compound Kit you mentioned, but I am a little curious as to why you had to use Griot's "detail spray" to "help with lubrication"?

Could it be that the watering down of the Meg's compound produced just enough extra heat on the fiberglass to bubble the paint?

Again, I am no expert on this. And your description of how you used the PC seems gentle enough. Just throwing an idea out to the AGO masses............
 
Is it only on the roof?
Z06's from that era had a recall for failing adhesive that required removing and replacing the roof panel, so it possibly could have been repainted by the dealer doing the recall. If you PM me the last 8 digits of your VIN, I can check it out on the GM Dealer Site.

Bill
 
PaulMys said:
I am far from an expert on this, but Corvettes are fiberglass, and I worked on boats for over 30 years.

Just my first thought, but I have seen this exact phenomenon on painted fiberglass that was overheated by rotary polishing.

I am not familiar with the Meg's Compound Kit you mentioned, but I am a little curious as to why you had to use Griot's "detail spray" to "help with lubrication"?

Could it be that the watering down of the Meg's compound produced just enough extra heat on the fiberglass to bubble the paint?

Again, I am no expert on this. And your description of how you used the PC seems gentle enough. Just throwing an idea out to the AGO masses............
Click to expand...

When I was first learning to how to use a buffer and pads i started with the Adams Polish system. The instructional video least back then showed spraying the bad with a little detail spray before setting it down for polishing.
 
04VetteZ06 said:
When I was first learning to how to use a buffer and pads i started with the Adams Polish system. The instructional video least back then showed spraying the bad with a little detail spray before setting it down for polishing.
Click to expand...

Yeah, not unheard of.

Personally though, with today's abrasive technology, I see no reason to prematurely saturate the pad.

Again, I may be way off base here. Just my thoughts on what I see in your pic.
 
PaulMys said:
Yeah, not unheard of.

Personally though, with today's abrasive technology, I see no reason to prematurely saturate the pad.

Again, I may be way off base here. Just my thoughts on what I see in your pic.
Click to expand...

This maybe a self inflicted wound. Its odd that it didnt happen on the hood as its fiberglass as well. And I dont see how I missed it for the past 3 years of ownership. Its just perplexing however that its hasn't happen on any other vehicle Ive had that had fiberglass panels.
 
04VetteZ06 said:
This maybe a self inflicted wound. Its odd that it didnt happen on the hood as its fiberglass as well. And I dont see how I missed it for the past 3 years of ownership. Its just perplexing however that its hasn't happen on any other vehicle Ive had that had fiberglass panels.
Click to expand...

I agree.

Very strange indeed. :(
 
04VetteZ06 said:
Not to plug another forum or anything, but I did a google search and according to the Corvette Forum I guess this happens a lot on the older Vettes that are fiberglass. Seen some post where people had it happen 2 years after a repaint.
Click to expand...

FYI, 'Vette bodies have not been strictly fiberglass for a long time, since the intro of the C3.

C1 & C2 bodies were hand-built, laying the fiberglass out by hand over body part fixtures. Front ends, for example, were made of many pieces thereby requiring bonding seams, which are a bane of owners of these gens of 'Vettes.

Beginning in '68, GM went to the use of SMC for 'Vette bodies in an effort to reduce labor costs and improve consistency. Also it produced a better surface finish eliminating the need for gelcoat.

SMC does include fiberglass in its composition, along with resins and other plastic fillers. But over the years the % of fiberglass used in the SMC has gone from about 40% in C3's to only about 15% in the latest gens.
 
57Rambler said:
FYI, 'Vette bodies have not been strictly fiberglass for a long time, since the intro of the C3.

C1 & C2 bodies were hand-built, laying the fiberglass out by hand over body part fixtures. Front ends, for example, were made of many pieces thereby requiring bonding seams, which are a bane of owners of these gens of 'Vettes.

Beginning in '68, GM went to the use of SMC for 'Vette bodies in an effort to reduce labor costs and improve consistency. Also it produced a better surface finish eliminating the need for gelcoat.

SMC does include fiberglass in its composition, along with resins and other plastic fillers. But over the years the % of fiberglass used in the SMC has gone from about 40% in C3's to only about 15% in the latest gens.
Click to expand...


I knew GM switched over to SMC decades above but the above is some good and meaty information.

Thank you for sharing.


:)
 
I took the car to the local paint and auto body shop to see what they thought. They are almost positive that it is something that reacted under the paint and not any wrong doing on my part. First thing they asked is if the roof had been repainted? The bubbles are definitely under the pain and not just the clear coat. Unfortunately they said they'd have to repaint the whole roof as the material thickness of the paint is unknown. Their 2 cents is that the few spot there are hardly noticeable and that I should wait to see if it gets worse before even considering the repaint. On top of that because my car is a LeMans anniversary edition I would need to track down the a replacement decal set. They advised against me color sanding it or even spot treating those specific spots for the reasons listed above.
 
04VetteZ06 said:
I took the car to the local paint and auto body shop to see what they thought. They are almost positive that it is something that reacted under the paint and not any wrong doing on my part. First thing they asked is if the roof had been repainted? The bubbles are definitely under the pain and not just the clear coat. Unfortunately they said they'd have to repaint the whole roof as the material thickness of the paint is unknown. Their 2 cents is that the few spot there are hardly noticeable and that I should wait to see if it gets worse before even considering the repaint. On top of that because my car is a LeMans anniversary edition I would need to track down the a replacement decal set. They advised against me color sanding it or even spot treating those specific spots for the reasons listed above.
Click to expand...

Your body shop gave you sound advice.
 
After some archival reading, I need to make a correction to my post above about Corvette's use of SMC for body parts.

While Corvette did switch to SMC on the C3, it was not done until the 1973 model year. What happened in 1968 was a process change that was done to lay the groundwork for the upcoming switch to SMC. In 1968 Corvette began press molding the body parts but they were still made from the traditional fiberglass+resin. This press molding process is similar to what is known as a drawing operation in the metal stamping world where draw dies are used to make things like sinks. A die set, comprised of a draw punch in the upper half of the die and a die cavity in the lower half, is used to form the material. The punch forces the material to flow down in to the cavity which gives/controls the part's final shape. The surface finish of the die cavity also influences the surface finish of the part produced, so these die cavities are highly polished and often nickel plated, etc.

Press molding should not be confused with vacuum molding which does not use a punch to force the material to flow in to the cavity but rather uses a vacuum to (essentially) "suck" the material in to the cavity.
 
Week later the bubbles seem to be spreading. is it possible moisture has gotten trapped in the fiberglass and is screwing with the adhesion of the paint from within?
 
You must log in or register to reply here.
Back
Top