Take it to the primer or bare metal

[bob86gn]

86 GN is in for a full paint. Body is in very good shape with almost no rust. The questions is take it down to bare metal or can we stop at the primer.
I have heard that if the primer was baked on and is in good shape it is better to stop there. What do you guys think?

 

[PLAINWHITE T]

I think you're going to get many opinions on this, but my car was in a very similar condition to yours from the sound of it. My body guy and I decided to just go down to the primer except in an area where there was heavy "checking" of the paint where we did go to metal. This was 3-4 years ago and things are holding up very well.

It's all time and materials either way you go.

 

[onefastgn]

86 GN is in for a full paint. Body is in very good shape with almost no rust. The questions is take it down to bare metal or can we stop at the primer.
I have heard that if the primer was baked on and is in good shape it is better to stop there. What do you guys think?

If you get all the paint off, it should be ok. But what i have seen with all the cars I've done is most have surface rust forming under the self etching primer they applied at the factory 20 plus years ago. If your sanding it down to primer, it's just another reassurance that you have seen it all in bare metal. I guess you will have to weigh your options as to how much more cost it will be to go to bare metal and take the chance that something could show up later down the line. If you plan on keeping the car for a long time and you are spending a good some of money i would go to bare metal and see whats under all the old primer. Just my 2 cents. Good luck either way.

 

[Chuck Leeper]

Check to see if the old primer is compatible w/ the new paint formula.........
If it's an original, it's probably lacquer..[My 86 is.]

 

[87chrisss]

Going to metal then using a sealer is the best way. if your going to keep the car might as well go all the way and then if you ever need to sell the bare metal resto will stand out more than most cars.

 

[bob86gn]

Thanks guys. Thinking bare metal is the way to go. Car is in good shape so when we DA through the paint (very easy) and saw how good the primer looked we starting thinking we should just stop there.

 

[Phoneguy]

I think that with the lacquer paint they used you are way better off going to metal...My wifes cousin owns 13 DuPont paint stores and has done bodywork/paint work for 25 yrs. He just did my car ...took it to bare metal even though he was not getting paid to do so. I have done all of his work for about 18 yrs at little to no cost so he wanted to repay me...car looks incredible ! Here is a link to my car

http://www.turbobuick.com/forums/threads/my-car-getting-a-long-needed-new-paint-job.386153/

If you can afford to have it stripped to metal, go for it you will not be disappointed ...

Bryan

 

[mikes86ttop]

Not knowing what's under that primer, I'd go down to metal and Start fresh your already more than half way there...Mike

 

[no-nos]

good info guys, I was just wondering the same, my problem and many of us down here in Miami , is that we cant find a reasonable paint and body shop, I paid $3000 for a paint job 4 years ago, and that was with me helping and me buying the paint. my paint is basically pealing right off, can someone please tell me why the paint has a bunch of bubbles of air, looks that way anyway, the dam paint is bubbling up or cracking, really disappointed I always keep my buick out of the sun. very hard to find a decent auto body shop, who won't try running your car when your not around. thanks for the info

 

[onefastgn]

good info guys, I was just wondering the same, my problem and many of us down here in Miami , is that we cant find a reasonable paint and body shop, I paid $3000 for a paint job 4 years ago, and that was with me helping and me buying the paint. my paint is basically pealing right off, can someone please tell me why the paint has a bunch of bubbles of air, looks that way anyway, the dam paint is bubbling up or cracking, really disappointed I always keep my buick out of the sun. very hard to find a decent auto body shop, who won't try running your car when your not around. thanks for the info

I see it sometimes, It always comes down to prep. Most likely there was surface rust/corrosion under the factory primer and or what ever they applied over the factory primer reacted to it later down the line. If they shot a epoxy primer over the factory primer, that would be the next best thing to having stripped the car to bare metal. The epoxy primer would have sealed it before the fill primer was applied. There is also the chance that if they wiped the car down before primer and didn't wait long enough before the solvent dried 100% that it could have trapped mositure between the factory primer and what ever they used. There is so many things that could have happened, it would be hard to pin point what really happened without knowing what there process was and if your car was sanded down to primer or just the paint sanded. You would have to fill in the blanks for me to give you a better idea what may have happened. I feel for you. Anytime in the past that i have seen pimples or small blisters after a paint job, its because i didn't have the surface prepped correctly and trapped containates between the bare metal or primers. Like i said before it's all about cleaning the surface. I use SPI waterborn 700-1 wax & greese remover. It does a great job cleaning the bare metal before the epoxy primer is applied. You have to wait a minimum of 1 hour before applying primer, and always use a epoxy primer first. Never just use a fill primer first because it wont fight corrosion like a epoxy primer does. It sounds like the next time you will have to strip the car to bare metal and hope they prep it right from the start. Good luck.
After thinking about this more did the blisters or bubbling start right away? or did it take 4 years before you noticed it?
Sorry Bob i dont want to Hijack your post buddy. Just trying to help out.

 

[onefastgn]

Bare metal is always best cleaned with #700-1 Waterborne Wax and Grease Remover then let it set 30-60 minutes before applying the epoxy!
After first reading our Epoxy Tech Sheet mix enough #6600 series epoxy to spray two wet coats over the entire car. Spray one wet coat and let flash about 30 minutes then apply a second wet coat. Let the epoxy set overnight then apply body filler, fiberglass filler or glazing putty over the epoxy. It is not necessary to sand the epoxy before applying the fillers as they will bite into the epoxy and feather great. When you have finished sanding all of the bodywork you are likely to have some bare metal spots from sanding. Spray one wet coat of epoxy over all filler spots and over any bare metal spots. Now let the vehicle set overnight.
The next day you can start spraying the 2K Primer over the epoxy. Once again, it is not necessary to scuff or sand the epoxy before applying primer. The most important thing to remember at this point is spray one wet coat of primer and let it set for 30 minutes before applying the second coat. Follow this procedure between coats of 2K Primer. This step when abused messes up more paint finishes than anything else!
When all of the primer blocking and any necessary primer repairs are finished it’s always best to use the epoxy as a sealer. Mix up enough epoxy to go around the car with one wet coat and adding a double shot glass of SPI #885 Urethane Reducer per quart. Let the epoxy set for 30 minutes. Stir one more time and strain. Spray one full wet coat of epoxy over the entire car. The epoxy should set for 2 hours before spraying basecoat or the next option is let it set over night and wet sand the epoxy with 400-800 then spray the base.
Next to rushing the 2K Primer rushing the basecoat is the second cause for the final gloss and depth of a paint job to look bad. It’s very important use the slowest urethane reducer in your basecoat that you can get away with regardless of outside temperature. Just allow enough extra time for the basecoat to flash off and dry. The difference between a very slow grade and medium grade reducer will show up in the final gloss. The slower grade reducer also has better solvency and will give you far better adhesion. Spray the first coat and let it totally dry before spraying the second coat. It’s best to wait 30-45 minutes between coats of base.
Option if your basecoat isn’t perfect:After two coats of base the vehicle should set overnight then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash. Apply the next two coats with 45 minutes of flash time in between coats. Some colors will require additional coats. If this is the case, again, wait 45 minutes between coats.
Let the basecoat set overnight.
A word of caution is there are 2-4 basecoats types that cannot be sanded or you will lose adhesion so avoid those basecoats. Check with your basecoat manufacturer.
Applying Clear:The following day tack off the vehicle then apply a wet coat of SPI Universal Clear or SPI MS Clear and let the first coat of clear set 30 minutes.
Spray the second wet coat of clear and let it set 30 minutes. Let the clear set for 30 minutes before apply the fourth coat as well.
Then proceed with normal wet sanding and buffing when you are ready.
Option number 2:From two days to two weeks after the job has been completed, wet sand the clear with 400-800 grit sandpaper to block out any orange peel or dirt. After wet sanding let the car set in sun for a day before remasking and degreasing then apply a wet coat of clear. Let the clear flash 30 minutes. Apply a second coat of clear, then 30 minutes later come back with a third coat of clear.
Let the vehicle set two or three days in the sun to help to get all of the solvents out and settle the paint job. If any wet sanding is required before buffing sand with 1500 grit sandpaper then set the vehicle in sun for two to three hours. Bring the car back into the shop and allow it cool to room temperature then buff.
If you follow these directions you will have a durable long lasting paint job with maximum depth and gloss over a solid foundation.
Neverwax a paint job applied this way for at least 90 days..

 

[onefastgn]

Also here is another reason that could have caused it.

Temperature at which the paint was sprayed; generally if the temperature is too hot, what will happen is you will get a skin will crust over on the outside of the, of the paint and not allow the solvent and the vapors to penetrate through which then causes the bubble to actually like push up through the paint. Inconsistency with the materials can cause bubbling and or blistering with paint which is, which is a major problem. The two contaminants; the chemicals actually force bonding to occur through act like paint dissolving into one another creating a chemical bond and when those are not compatible, they can cause a blister or bubble. Water vapor in your air lines can cause bubbling or blistering because when you're spraying the paint it goes on, there's water droplets that are trapped inside the paint and when the paint heats up and starts to cure, the water doesn't have anywhere to go and so it actually just builds up pressure inside there and forces its way out. So you need to understand what the source of the bubbles are so that you can prevent them from happening beforehand.
Do you have any pictures?
​

 

[bob86gn]

Sorry Bob i dont want to Hijack your post buddy. Just trying to help out.

Not at all, I am learning alot from this and what could happen, keep em coming.

 

[GainesvilleGN]

Excellent recommendations from onefastgn. IMO by the time you DA with 80 grit down to primer, you're gonna have quite a bit of metal showing anyway.
once you get to that point, I switch over to 180 grit paper to finish removing the rest of the primer. Try to time it so that you can get the car in epoxy within 24 hours. Any top surfaces will have some checking or weather damage that will be better addressed by going to metal. Be sure to remove the filler panel between the deck lid and the back window. The underside of this panel had NO paint from the factory. Every GN, T, whatever is gonna have some surface rust in there. May as well take care of it now.

 

[bob86gn]

Good call on the filler panel. I pulled that off before and put some por-15 on the back of it but did not get the top of the trunk under it.

 

[no-nos]

great info onefastgn, I am sure they used no epoxy primer, it was sanded down to primer. the paint started to bubble in its second year. I do not remember waiting 1 hour after wiping the car down, it was wiped and then he closed the booth doors, he never even wet the floor, to avoid dust( not sure if it is a must do thing, but he told me , "no I wet it earlier" I just did not know enough, ( shame on me , won't happen again )
I am printing the RED post you posted, GREAT INFO, thanks onefastgn, shows me , I have a lot to learn. outstanding info. I will take pics and post asap, but please be kind , I know it looks horrible