So, I finally found this section of the forum, yeah!
I was on the "General" section, but thinkl this is definitely where I need to be right now.

I recently decided to paint "Sterling", my 82 Vette, because it was fading and the paint on the quarter ridge where the antenna is located began to crack (I suspected PO work). From underneath, there has definitely been some work done (pre-1993 when I bought her).
So I started grinding, and low and behold, that crack went everywhere!!!
So, that left a hole bigger than my hand! So, I took Dub's advice and did the feather grinding and glassing from underneath, then from above, then back underneath, then back above until it all felt really solid. Then I started sanding. The shape is now back, but, I had some pinholes and small voids.
Help me here . . . I ground the voids and pinholes back out and put more resin and fiber in it.
After that, I still had some small pinholes. Can I just use some of the resin and smooth it over? Or should I now switch to the filler techniques?
I have some pics, but didn't want to clutter the place up, unless you want to see them.
Thanks for the advice!

 

No need for photo's.

YES...it is time for you to lightly grind down your laminated repair area and apply Fiberglass/Evercoat Vette Panel Adhesive. Part # 870 (quart) Part # 880 (gallon).

You want to try to achieve at least the thickness of a paper matchstick..or the thickness of the "safe end" of a single edge razor blade....OVER your laminated area if possible..and then feather it outwards. Hopefully you do not find tons of air bubbles after you grind it and blow it off with CLEAN, DRY air. If you do...and depending on the size of the air bubbles will determine if grinding it all out and re-laminating it again from the top. If the bubbles are very small...I would not worry about it...and that is what I want the thickness at what I mentioned because if you apply a SUPER thin razor blade thin coat on your lamination...and for some reason there is a hidden large bubble JUST BELOW the surface...this large bubble will grow and due to not having enough VPA on it...and will not hold it down.

DUB

 

Thanks Dub! Since i didn't get this post until this morning, I might have goofed up last nite.
It looked so good (to me anyway) that I sprayed some filler primer on it to check out the fender ridge to make sure it had the right sharpness and curve to it.
I have no idea where to get the Evercoat stuff. I'll do a search. But, look at the pic, it actually came out smoother, without pinholes, than I thought it would. The smoothing "resin coat" seemed to take care of the pinholes. By the way, there were no big air bubbles or anything. Just a few small dots the size of a blunt pencil point.
Do I need to sand off all this primer and Evercoat it?

 

Not at this stage. If the primer is filling in these small imperfections..keep applying it...even if you have to use a small artist brush and isolate the drop of primer on the pinhole itself. Then let it dry and sand again.

BAD NEWS...or hopefully it was corrected PRIOR to priming.

In your photo's of your laminating I see how you applied the resin over the dark red oxide primer that was still on the panel. IN MY OPINION...that is a BIG NO-NO. AND would not even come close to "flying" at my shop. You are asking for problems if you apply resin over primer. I am not saying that you will have a problem...but I have learned in the past that the surface MUST be free from anything that is on the bare fiberglass/SMC. Because there is NO GUARANTEE that the resin will correctly bond to a product that it was not designed to adhere to. The reason being...I fix so many jobs done by "BOZO"...that I can often times take my small seam splitter and get under a resin patch that is on primer and pop it right off will very little effort. Also....not to add any more injury...I would have removed all of the dark red oxide primer and light blue "stuff" before I shot any primer on the car. I am in the FIRM belief (because it has "back fired" on me in the past) that leaving ANY primer on the body or layers of different products on the panel PRIOR to priming is a recipe of a potential problem that will POSSIBLY surface in the future. I know many bodymen/painters that do it like you did it...but I have also seen the car a few years later and you can see "issues" due to these products that were left on the panel are now showing themselves once the primer and paint has cured and settled down. And I have seen some cars that show no problems at all also. I just do not like playing the "odds". If there is not a solvent based product on the panel prior to priming...then you will not have an issue due to nothing is on the panel to allow a reaction or potential distortion in the future. The disclaimer to this is that IF the panel is from a new Corvette...and the panel has not been shot on by someone other than the factory...then I can prep the repair area and leave the remaining paint on it. But this is on NEW stuff. NOT old stuff. Which is COMPLETELY different all together. It deals with the spotty areas where it is down to raw SMC in some areas and not in others. This is where a "ring-out" effect can show up in the future....especially on the top surface where it will often times get a lot more direct sun than the areas at the bottom of the doors or quarters.

ONCE again...it is what I am seeing from the photo's you posted.

DUB

 

Thanks Dub! So, after reading your post last nite before I got started, I sanded it back down to the glass to double check.
If you look closely, you'll see that the only area that got the patch is actually sanded and feather-ground back to fresh SMC. I feel pretty confident that the repair is ONLY on the fresh SMC.
I ground the back side of the panel the same way.
Do you think it will pass?

 

Why not get rid of the old red oxide primer? There is no way it will hold as well as the primer you put on top and it adds a significant risk for future problems. I mean, you're already putting so many hours into it, what's a few more removing the primer and be sure it's good?

 

Zwede! Totally! I dig it. I'll put all the hours in the world in it. I just need advice like this to help me understand that I actually need to do that!
So, If you look closely, you will see (from paint to glass) I have silver paint, white (I don't know), brown primer, blue (I don't know), brown primer, yellowish-green (I don't know), then the fiberglass.
This car was straight as an arrow before I started, except for the crack around the antenna well, so I was hoping not to go down past what someone else has already spent a boat-load of time getting nice. I thought that I would fix the crack, sand off the paint, seal, re-prime, and then paint. Not so?

 

I've seen many cars with multiple paint jobs that crack after a few years. The paint is just too thick. You also don't know what old repairs may be hiding under that old paint. I found plenty of bad repairs once I got mine all stripped.

All depends on what you're after. If it's a car you plan to keep for a long time, and you want it to look really good, taking it down to 'glass is the way to go.

 

I'll be sanding off most of the current paint and primer, at least to give the new primer a good tooth to adhere to.

 

That is the dilemma many bodymen/painters go through. Leaving a previously applied product on the car is a gamble. REGARDLESS if it looks good now...in a few years it can fall apart. And the main reason is the prep. DID THEY prep it correctly for the long haul.

So like what I wrote in my previous post...I would get everything off the panel(s). Especially with all the layers ans it not being a new Corvette...which fall under a different procedure.

AS long as the resin applied to your repair is NOT on anything but raw, bare SMC...then your repair is fine. If you have resin on any of the other stuff....even a little bit...sand it off.

I would still highly advise applying a thin layer of Vette Panel Adhesive over your laminated area. I do not apply primer directly over any of my laminated areas and I am quite good at it. It is a mental thing for me...because on some jobs I have laminated and primed over (not on Corvettes) in time I could see "stuff" that I did not like. And the amount of time for this insurance is worth it to me....because I always fall back on my saying..."WOULDA","COULDA", "SHOULDA".


DUB

 

thanks Dub.
I think I when I sand it down, I will be able to tell where previously repaired areas are and can concentrate on those areas, as you have suggested.
I kinda doubt there are many of them because I've had the car 20 years, and this rear quarter is the only area that has ever shown any signs of "fatigue".
Question: Is the "VPA" used in place of an icing type product? Is it meant to smooth the surface in prep for priming?
If I have to do any Bondo, do I actually use Bondo? and do I use it over, or under the VPA?
To sum up, should it be (from bottom up):
a. fiberglass
b. VPA
c. Bondo
d. Primer
e. Sealer
f. Paint

Or do I have them all out of order? wrong components?

 

ORDER:
a.) SMC ( fiberglass)
b.) Vette Panel Adhesive
c.) Primer
d.) Sealer
e.) Paint / Clear

I usually do all of my fill work with the VPA. Even when it gets to fine / small pinholes. I fill those in with the VPA also. And when I do fill them in I use a razor blade as the spreader. This way I can isolate the area and apply a very thin tight coat with good pressure to force the VPA into the pinholes.

If we have not talked before. it might be worth your time to call me and I can give you a quick tutorial on use the VPA. This way you do not over work yourself.

(704) 394-5150 EST M-F 8-5 Sat-Sun 10-4

DUB

 

Very interesting dub, I am an older retired collision expert,done my share of vette work,but on my 99 rocker panel i have damage ( stress cracks and a gauge) that I have been putting off as well as refinishing my front bumper cover.I totally agree with your methodologies regarding getting all the old stuff off.Question is: What product is used on the rocker to fill etc,and what is the best flexible products for the bumper cover (small imperfects) and primer sealer,paint additives etc....been out of the game some 20 years now,don't know which products are the best...plan on keeping this car a long time.p.s do you know what brand paint matches the sebring silver color the best..hate it when covers don't match..dont want to blend up into the hood etc if i can help it..I know this is a lot, but from reading other threads you seem to really know your stuff, Any pearls of wisdom would be deeply appreciated. Thanks ,wlean99

 

I'll call you as soon as I feel free to bug you without you turning on your answering machine
As for any waves or "not straight" panels, do you fill the low spots with the VPA? or do you use something else?

 

Contained in your previous post for the repair; will this stuff also work to bond the hood skin to it's frame? The last time I asked this question to a paint shop, they sold me this uber-expensive 3M pink-stuff and a gun that mixes it as it comes out. I ground it all down and used lots of spring clamps to hold it together until it cured. Thought it was done. Well, needless to say it didn't work, the bonding is coming undone once again.

 

The answering machine is with AT&T...it is not a machine I can turn off...so-to-speak....but call when you can...if you need to.
ALL repair work is completed with the VPA. I do not use any glazing putties , etc.

DUB

 

You do know about the characteristics of SMC don't you??? So it all depends on what happens when you go in and begin prepping your stress cracks in your rocker on what will be needed to repair it..

And as you know...no paint manufacturer is best when it comes to paint matches...( that was a "trick" question). The color match will all depend on the person mixing and shooting test panels and tinting it to get it to a good "blendable" match. If you were in the industry...this is a common occurrence when trying to match an existing color with age and fade issues.

And as you should know..when your car was being built and painted...the bumper covers are shot in separate area than the rest of the body with completely different materials. Thus...the color is off.

If you need more info...reply to this or PM me.

DUB

 

You MUST be SPECIFIC!!!

What type of hood???
What year did it come off of????
Is it a factory hood or aftermarket???

I have to know what the hood is made out of to give you a correct answer.

The correct prep procedures have as much to do with a panel adhering as the correct adhesive. You might think that grinding is often times the BEST way to get something prepped for an adhesive to "bite" and adhere....BUT....you are highly mistaken. I know...I know...that does not make sense...but it is true. Scuffing a panel can be the best method...once again...it depends on what the material is...that is why I need to know. Sometimes actually sand blasting the fiberglass is best.

BUT...NOTHING...and I mean NOTHING is better than making 110% sure that the surface is CLEAN AND DRY!!! More times that I can count I have encountered my guys in the past getting ready to apply an adhesive or "something" else....and when I go and check before the application of it...I can tell that it has NOT been thoroughly cleaned after the prep and I know that the super thin layer of dust, etc that is on it can "possibly" cause for lack of proper adhesion. If you don't believe me...pull some masking tape off the roll and go stick it on the side of something that you know has a very thin film of dust or "whatever" and see how well the tape sticks. In repairs much like what you are doing again...I also do not have time to do it a second time...so the initial repair has to be right the first time. And people wonder why the repairs can be so costly in some cases.

DUB

 

It's been too many years since I used the stuff, I'd have to come across the receipt. It was 3M, pink like bubble gum and 2-part mixed like epoxy (in an application gun), but not epoxy. Both surfaces were clean, flat and jitterbugged, not scuffed. Clean and dry (tack rag). I put a good bead all around and used something like 18 spring clamps to hold it until cured. Several years later, it starts to let go in the corners.. again.

It's a 71; fiberglass not SMC. I don't think the hood is aftermarket, but I can't be sure. It's too old and beat-up to tell. What ever bonding that was on there the first time started to "pop", that's why I had to redo it.

 

factory hood will be slick on the underside of the hood skin. If it is a hand laid part. The surface will be rough ( in most cases).

Also...the rivets that hold the pieces to the under structure...IF FACTORY will NOT be pop rivets....and they are actually aluminum solid rivets that have been bucked (squashed).

DUB