Advice please, paint bubbles on hood
01-30-2017, 09:12 AM
#1
Advanced
Thread Starter
Advice please, paint bubbles on hood
I have bought a Donner car for parts for my 1976 build project. It came with a nice crack free hood and I would like to use it for my project. I have no history for the donner car but it had been repainted sometime in its life. I do understand all the paint will need to be removed down to the raw fiberglass. Here's the problem; there are hundreds of BB size bubbles under the paint on the new hood. I scraped the paint back in several spots and it looks like the contamination is in the fiberglass. Looks like after the hood was painted the suns heat gassed something off under the primer, just a guess. My question; if I remove all the paint down to the raw fiberglass is there a way to make sure the contamination want return. This is a long term project so if I need to put the stripped hood out in the sun for a period of time to gas off that's no problem. Any help and suggestions are appreciated.
Mark
Mark
The following users liked this post:
marks76ray (01-31-2017)
01-30-2017, 05:42 PM
#3
Race Director
If you can post photos of the spots that had a bubble above it would be great.
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
01-30-2017, 10:54 PM
#4
Advanced
Thread Starter
If you can post photos of the spots that had a bubble above it would be great.
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
Mark
01-31-2017, 01:04 PM
#5
Advanced
Thread Starter
If you can post photos of the spots that had a bubble above it would be great.
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
I am also curious of the color of the primer that is under the paint that you scraped off.
Are there bubbles like this anywhere else on the car??? Important to know this also.
And...you being in Mississippi humidity is never a problem down there. I am sure it is dry all the time.(joking). So...I asked if there were these bubbles anywhere else due to if the previous owner used a car cover...or put plastic over the car...these bubbles can show up due to trapping moisture and creating a 'greenhouse' effect.
The reason I asked about the primer color is if someone had already stripped the paint off sometime in the cars life and painted it....and the primer they used might not have been as good as it possibly can be.
If you have small spots that stained the panel...which should be a light gray color...so these dots may appear to be darker gray. And if it is like that.....I hate to say...that now the fiberglass panel has more than likely been contaminated....and gettign it all out and NOT come back can sometimes be a 'hit or miss' situation. The condition of the paint on the underside of the hood is JUST AS important. If it is also peeling/flaking/blistering off...this is NOT GOOD.
I will wait to comment any further until you reply and can provide what has been ask of you.
DUB
So on to the problem
All I have that matches the hood is the fender. It has some bubbles but not near as much as the hood. I really couldn't capture the bubbles on the fender, they are small.
There are several layers, looks like top coat paint, primer, old maroon paint, primer then fiberglass. I think the old lacquer primer is gone.
You can see the round circles in the primer.
Here's a top coat color paint scraping bottom and top
I went ahead and hit it with my DA to better see the layers
Here's some shots of the under side of the hood
And raw fiberglass under the hood
Thanks DUB
Mark
01-31-2017, 06:14 PM
#6
Race Director
Thanks for the very good photos.
QUESTION:
Did the T-tops and any other top surface have these bubbles in it???
And I bet the bubbles in the fenders are above the center horizontal body line also. And I am sure there may be some in the top hood surround also.
I BET that the doors are perfect BELOW the center horizontal body line also...but there may be few that are in line with where the mirror attaches.......which...leads me to think that this is moisture contamination.
The reason I feel it is moisture damage is due to the spots you can clearly see that go all the way to the gray panel.
It looks like the paint job after the facotry used the old K200 primer from PPG. The they sealed it and shot the paint.
In my opinion...there is nothing that can be shot on these damaged panels to stop the event of moisture constantly coming out of the panel that has been sacrificed. It is a guessing game. And just by seeing what you have going on....on how the bubbles can make it through ALL of what was on the panel currently.....so no NEW AGE primer is going to stop this. The only primer that I might try is a polyester primer....but that is also NO GUARANTEE.
It is a guessing game also if you put the hood in a bake booth and run several 'bake' cycles to get it hot and cool down.
ALSO...carefully look and see if these hood bubbles are located above the area where the understructure is bonded on the outer skin. This creates an air cavity...that may breathe...but is also a greenhouse if it gets wet inside that cavity. Moisture rises when it evaporates and then can not go any where and begins to penetrate the underside of the outer skin...but yet NO bubbles in the bond seam area. Think about it. And YES..I know the hood has bubbles that are outside this area.
I have seen hoods where the bubbles were ONLY above the cavity area...which then leads me to believe the person washes the underside of the hood with running water and has allowed water to get into this cavity....even though there are drain holes at the bottom, it is now wet.
The ONLY other suggestion is to get a hold of WEST SYSTEMS and talk with them and see if they can suggest a product in their line that you could use to apply like a resin to create a solid barrier. Just make sure to get all recommendations from them to make sure what ever you apply on their product if you use it it will adhere.
DUB
QUESTION:
Did the T-tops and any other top surface have these bubbles in it???
And I bet the bubbles in the fenders are above the center horizontal body line also. And I am sure there may be some in the top hood surround also.
I BET that the doors are perfect BELOW the center horizontal body line also...but there may be few that are in line with where the mirror attaches.......which...leads me to think that this is moisture contamination.
The reason I feel it is moisture damage is due to the spots you can clearly see that go all the way to the gray panel.
It looks like the paint job after the facotry used the old K200 primer from PPG. The they sealed it and shot the paint.
In my opinion...there is nothing that can be shot on these damaged panels to stop the event of moisture constantly coming out of the panel that has been sacrificed. It is a guessing game. And just by seeing what you have going on....on how the bubbles can make it through ALL of what was on the panel currently.....so no NEW AGE primer is going to stop this. The only primer that I might try is a polyester primer....but that is also NO GUARANTEE.
It is a guessing game also if you put the hood in a bake booth and run several 'bake' cycles to get it hot and cool down.
ALSO...carefully look and see if these hood bubbles are located above the area where the understructure is bonded on the outer skin. This creates an air cavity...that may breathe...but is also a greenhouse if it gets wet inside that cavity. Moisture rises when it evaporates and then can not go any where and begins to penetrate the underside of the outer skin...but yet NO bubbles in the bond seam area. Think about it. And YES..I know the hood has bubbles that are outside this area.
I have seen hoods where the bubbles were ONLY above the cavity area...which then leads me to believe the person washes the underside of the hood with running water and has allowed water to get into this cavity....even though there are drain holes at the bottom, it is now wet.
The ONLY other suggestion is to get a hold of WEST SYSTEMS and talk with them and see if they can suggest a product in their line that you could use to apply like a resin to create a solid barrier. Just make sure to get all recommendations from them to make sure what ever you apply on their product if you use it it will adhere.
DUB
01-31-2017, 09:01 PM
#7
Advanced
Thread Starter
QUESTION:
Did the T-tops and any other top surface have these bubbles in it???
DUB unfortunately I only received the red hood and red fender during the purchase of the donor car. The hood and fender were just extra parts separate from the donor car purchase. So no T-tops or other top surfaces. The hood from the donor car is in real bad shape and in my opinion not usable. My original hood that came with my white vette has a great top surface but the bonding supports under the hood have several cracks running across the supports where the red hood is structurally perfect.
And I bet the bubbles in the fenders are above the center horizontal body line also. And I am sure there may be some in the top hood surround also.
DUB I looked real hard at the red fender, the bubbles are very small and not near as many as the hood. There are more bubbles towards the front side of the fender on the side where the turn signal light is. A few but not many over the wheel arches and back of the fender. The top surround has about the same as above the wheel arches on the side. The headlight area only has a few.
I BET that the doors are perfect BELOW the center horizontal body line also...but there may be few that are in line with where the mirror attaches.......which...leads me to think that this is moisture contamination.
DUB unfortunately I do not have the doors.
The reason I feel it is moisture damage is due to the spots you can clearly see that go all the way to the gray panel.
DUB yes they do, I did not find any factory lacquer primer, this leads me to believe the first paint job under all this is not original to the car. When heated the blue paint became gummy, not like the enamel I have been removing from the other paints.
It looks like the paint job after the facotry used the old K200 primer from PPG. The they sealed it and shot the paint.
DUB I believe this to be true.
In my opinion...there is nothing that can be shot on these damaged panels to stop the event of moisture constantly coming out of the panel that has been sacrificed. It is a guessing game. And just by seeing what you have going on....on how the bubbles can make it through ALL of what was on the panel currently.....so no NEW AGE primer is going to stop this. The only primer that I might try is a polyester primer....but that is also NO GUARANTEE.
It is a guessing game also if you put the hood in a bake booth and run several 'bake' cycles to get it hot and cool down.
DUB at this point it may be better to repair my original hood.
ALSO...carefully look and see if these hood bubbles are located above the area where the understructure is bonded on the outer skin. This creates an air cavity...that may breathe...but is also a greenhouse if it gets wet inside that cavity. Moisture rises when it evaporates and then can not go any where and begins to penetrate the underside of the outer skin...but yet NO bubbles in the bond seam area. Think about it. And YES..I know the hood has bubbles that are outside this area.
I have seen hoods where the bubbles were ONLY above the cavity area...which then leads me to believe the person washes the underside of the hood with running water and has allowed water to get into this cavity....even though there are drain holes at the bottom, it is now wet.
DUB I went back and looked close, there is no pattern on the bubbles. They are all over the hood, thousands of them, and are everywhere. There is no bubble free area on the hood.
The ONLY other suggestion is to get a hold of WEST SYSTEMS and talk with them and see if they can suggest a product in their line that you could use to apply like a resin to create a solid barrier. Just make sure to get all recommendations from them to make sure what ever you apply on their product if you use it it will adhere.
DUB I am thinking it may be better to repair my hood that came with the white vette, only thing wrong with it is cracks in the supports. The top is in great shape, if needed I could remove the support strips from the red hood and bond them to the white hood or just repair the cracks with epoxy and glass. Another thing to throw in is I have to graft a L88 scoop on the hood. I need to do this for clearance for my 8.1L engine. So a lot of work will be done to the hood. Your thoughts are needed, i'am no professional just have been a car guy all my life and i'am 54. I feel confident I can do this, I just take my time and ask advice and try to make good decisions. Thanks DUB for your time
Mark
Did the T-tops and any other top surface have these bubbles in it???
DUB unfortunately I only received the red hood and red fender during the purchase of the donor car. The hood and fender were just extra parts separate from the donor car purchase. So no T-tops or other top surfaces. The hood from the donor car is in real bad shape and in my opinion not usable. My original hood that came with my white vette has a great top surface but the bonding supports under the hood have several cracks running across the supports where the red hood is structurally perfect.
And I bet the bubbles in the fenders are above the center horizontal body line also. And I am sure there may be some in the top hood surround also.
DUB I looked real hard at the red fender, the bubbles are very small and not near as many as the hood. There are more bubbles towards the front side of the fender on the side where the turn signal light is. A few but not many over the wheel arches and back of the fender. The top surround has about the same as above the wheel arches on the side. The headlight area only has a few.
I BET that the doors are perfect BELOW the center horizontal body line also...but there may be few that are in line with where the mirror attaches.......which...leads me to think that this is moisture contamination.
DUB unfortunately I do not have the doors.
The reason I feel it is moisture damage is due to the spots you can clearly see that go all the way to the gray panel.
DUB yes they do, I did not find any factory lacquer primer, this leads me to believe the first paint job under all this is not original to the car. When heated the blue paint became gummy, not like the enamel I have been removing from the other paints.
It looks like the paint job after the facotry used the old K200 primer from PPG. The they sealed it and shot the paint.
DUB I believe this to be true.
In my opinion...there is nothing that can be shot on these damaged panels to stop the event of moisture constantly coming out of the panel that has been sacrificed. It is a guessing game. And just by seeing what you have going on....on how the bubbles can make it through ALL of what was on the panel currently.....so no NEW AGE primer is going to stop this. The only primer that I might try is a polyester primer....but that is also NO GUARANTEE.
It is a guessing game also if you put the hood in a bake booth and run several 'bake' cycles to get it hot and cool down.
DUB at this point it may be better to repair my original hood.
ALSO...carefully look and see if these hood bubbles are located above the area where the understructure is bonded on the outer skin. This creates an air cavity...that may breathe...but is also a greenhouse if it gets wet inside that cavity. Moisture rises when it evaporates and then can not go any where and begins to penetrate the underside of the outer skin...but yet NO bubbles in the bond seam area. Think about it. And YES..I know the hood has bubbles that are outside this area.
I have seen hoods where the bubbles were ONLY above the cavity area...which then leads me to believe the person washes the underside of the hood with running water and has allowed water to get into this cavity....even though there are drain holes at the bottom, it is now wet.
DUB I went back and looked close, there is no pattern on the bubbles. They are all over the hood, thousands of them, and are everywhere. There is no bubble free area on the hood.
The ONLY other suggestion is to get a hold of WEST SYSTEMS and talk with them and see if they can suggest a product in their line that you could use to apply like a resin to create a solid barrier. Just make sure to get all recommendations from them to make sure what ever you apply on their product if you use it it will adhere.
DUB I am thinking it may be better to repair my hood that came with the white vette, only thing wrong with it is cracks in the supports. The top is in great shape, if needed I could remove the support strips from the red hood and bond them to the white hood or just repair the cracks with epoxy and glass. Another thing to throw in is I have to graft a L88 scoop on the hood. I need to do this for clearance for my 8.1L engine. So a lot of work will be done to the hood. Your thoughts are needed, i'am no professional just have been a car guy all my life and i'am 54. I feel confident I can do this, I just take my time and ask advice and try to make good decisions. Thanks DUB for your time
Mark
02-01-2017, 05:43 PM
#8
Race Director
I do agree if you were to separate the two hood and make one good one...it would also allow you to strengthen the internal area of the good understructure.
I can say this is IF the understructure of your original white hood has the cracks in the weak spots in the understructure. Just make sure you do the very best you can in repairing this area and laminating in more mat and resin. This area may seem easy but is quite touchy to get it really strong again. I have repaired to many to count...so it can be done but takes a bit more focus....in my opinion.
The blistering on the other panels you replied about...regardless on how small they may be...is the beginning of the end.
DUB
I can say this is IF the understructure of your original white hood has the cracks in the weak spots in the understructure. Just make sure you do the very best you can in repairing this area and laminating in more mat and resin. This area may seem easy but is quite touchy to get it really strong again. I have repaired to many to count...so it can be done but takes a bit more focus....in my opinion.
The blistering on the other panels you replied about...regardless on how small they may be...is the beginning of the end.
DUB
The following users liked this post:
marks76ray (02-02-2017)
02-02-2017, 12:45 PM
#9
Advanced
Thread Starter
I do agree if you were to separate the two hood and make one good one...it would also allow you to strengthen the internal area of the good understructure.
I can say this is IF the understructure of your original white hood has the cracks in the weak spots in the understructure. Just make sure you do the very best you can in repairing this area and laminating in more mat and resin. This area may seem easy but is quite touchy to get it really strong again. I have repaired to many to count...so it can be done but takes a bit more focus....in my opinion.
The blistering on the other panels you replied about...regardless on how small they may be...is the beginning of the end.
DUB
I can say this is IF the understructure of your original white hood has the cracks in the weak spots in the understructure. Just make sure you do the very best you can in repairing this area and laminating in more mat and resin. This area may seem easy but is quite touchy to get it really strong again. I have repaired to many to count...so it can be done but takes a bit more focus....in my opinion.
The blistering on the other panels you replied about...regardless on how small they may be...is the beginning of the end.
DUB
Thanks DUB I think we agree, it will be more work but all I have is time. Did you see the posts in the general section on the car cover causing bubbles? very interesting he said he had the same cover on his nova and discovered bubbles there also, worth reading. Here's a link
https://www.corvetteforum.com/forums...-of-hives.html
Looks a lot like my hood just easier to see
02-02-2017, 05:46 PM
#10
Race Director
Thanks DUB I think we agree, it will be more work but all I have is time. Did you see the posts in the general section on the car cover causing bubbles? very interesting he said he had the same cover on his nova and discovered bubbles there also, worth reading. Here's a link
https://www.corvetteforum.com/forums...-of-hives.html
Looks a lot like my hood just easier to see
https://www.corvetteforum.com/forums...-of-hives.html
Looks a lot like my hood just easier to see
YEP...moisture contamination....without a doubt.DUB