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Ive been putting off repainting our 64 after hearing all the discussions about stripping it this way or that way,using lacquer,urethane,enamel etc,then hearing all the horror stories about the paint bubbling off after a short period of time.I know of two instances where lacquer was used and when left outside under a car cover one developed flash marks in the paint and the other developed many bubbles in the paint. Im not sure if the flash marks were caused by poor preperation or not but the bubbled paint could have been.I read in a post below that one suggestion to a paint problem was to use an epoxy primer.I know primers like DP-40 do a very nice job on sealing metal but never thought about using it on fiberglass and wondered if the DP would help keep the topcoat on the car? It just seems like its getting harder to find a combination of preparation and paint that looks great and would last at least half as long as the original paint did.
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Re: Repainting Fiberglass
Don; yes use DP-40 and other e-poxies on the glass as long as the other cleaners have had plenty of time to dry out of the glass. Some good sun time or heated paint booth will do this well. Then when you put the e-poxy on let it tack up or just beyond and then spray a catalised filler primer on so it bits into the e-poxy. After your first sanding or even more body work just use filler primer after that unless you go through to the glass again, in which case just cover with e-poxy again.
When using chemical strippers just do small areas and clean with laqr. thnr. to stop the action and clean the glass. Sand with 180 and e-poxy prime. Many bubbles come from water either trapped or getting under the paint. The factory had plenty of problems on the 63-67's because they water sanded the bare glass and trapped water in pockets around the seam areas.
A good freind of mine used the following method to paint a show wining 67 conv.: Strip and sand; then sprayed e-poxy resin (west Marine); when dry sanded with 220; went right to laquer paint(Goodwood Green); after 2 months shrinkage (only because of the laquer) wet sanded with 1500/2000 and polished! That's right, no regular primmer at all! The laquer has a mechanical bond only, the paint is 7 years old and is awesome!!! David -
Re: Repainting Fiberglass
Most epoxy primers are thin and do not fill and surface well, but there are those out there that do. I use Akzo-Noble #380. It is very thick and fills and sands well. Eliminates several steps.Comment
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Re: Repainting Fiberglass
I know primers like DP-40 do a very nice job on sealing metal but never thought about using it on fiberglass and wondered if the DP would help keep the topcoat on the car?
Indubitably!!! In fact, Dick Whittington says DP epoxy primer will bond to (window) glass and is nearly unremovable! I would use DP74LF instead of DP40LF...DP74LF is the same red-oxide color as the original factory primer, while DP40LF is gray-green in color. Read the DPLF product sheet in the link below. Click on "PPG DP LF Epoxy Primer LF" near the bottom of the first column...everything you need to know about PPG epoxy primers.
It just seems like its getting harder to find a combination of preparation and paint that looks great and would last at least half as long as the original paint did.
Nah! You're suffering from information overload. If you want it to last as long as the original acrylic lacquer, go with modern urethane products. Of course, you could take a beating in judging, but steps can be taken to make urethane appear as acrylic lacquer. Some say it can't be done...others say yes it can. I don't know one way or the other; I expect it depends a lot on the painters skill and the eye of the critical observer.
Corvettes have been chemically stripped for decades: There is an excellent "Corvette Restoref" article by Armand Filer with step by step instructions for stripping a Corvette. I am pretty sure the article is available on the CD collection for sale in the NCRS Store.
If you start with PPG DPLF primer, then you want to continue with PPG products throughout and not mix other brands. Guys here recommended a good system to me in PPG single stage acrylic urethane:
Primer: DPLF epoxy primer
Primer-surfacer: K36 acrylic urethane primer-surfacer (This stuff is thick and goes south fast; mix small batches, reduce and use a large fluid nozzle.)
Sealer: DPLF epoxy primer (reduced)
Color: DCU single stage acrylic urethane
Clear (optional): DCC clear
AutoBodyDepot Product SheetsComment
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Re: Repainting Fiberglass
Yep, Chuck is correct on the information overload about paint. I have been chemically stripping Corvettes for over thirty years and haven't had a problem after doing several dozen. I have always used a stripper that can be cleaned off the surface with water. That stripper is Kleen Strip Formula A. I have also waited a sufficient time for the water to evaporate from the fiberglass. I have painted with Nitrocelluose lacquer, Lacquer, Urethane and BB/CC and have followed the manufacturers suggestions with success on each Corvette.
Listen to the pros when it comes to painting. Each have their own methods but each follow the paint manufacturers suggestions.
When you listen to the people who strip and paint in their driveway you are going to hear horror stories. Also, you will hear success stories from those people but they are rolling the dice.
Problems always arise when shortcuts are taken and sufficient time is not taken between each step.
My two cents,
Regards,
JRComment
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Re: Repainting Fiberglass
Chuck and Joe have posted some very good advice. No matter what, stick with ONE manufacturer. If you have a problem, you have a place to go. If you mix product manufacturers, the finger pointing starts, and you are the loser. Another note. K-36 will render your paint gun useless in a short period of time (again do not ask how I know ). Mix just what you need at the moment, use it, and immediately clean the paint gun thoroughly.Dick WhittingtonComment
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Re: Repainting Fiberglass
Dick, I had a little trial episode with K36 recently, and learned all stuff they don't tell you the hard way. I finally got to where I was mixing a cup (20oz) or less each time. Without reduction, the pot life is 30 minutes!!! (They do tell you that.)
But the good news...it is good stuff; experts will tell you not to have scratches coarser than 80 grit...that K36 was filling 36 grit grinder marks without a trace. This was a metal bodied car, and it would probably be risky to leave 36 grit marks on a Vette.Comment
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Re: Repainting Fiberglass
I would use the DP40 on your stripped fiberglass. It will act as a sealer and provide good adhesion. However, the DP is a non-sanding primer. After your DP40, use K36 for a high build sandable primer, and go through your block and reprime process. After block and reprime, spray another couple of coats of DP40 to provide good adhesion to your color coat. The DP40 provides a chemical bond, and has much better adhesion. This process requires a little more time and money, but could help prevent potential problems. One note on DP40, you can't let it sit for more than a few days before spraying your K36 or color coats. If it sits too long, you will have to sand it down and lose the advantages of the chemical bond.Comment
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Re: Repainting Fiberglass
Chuck
Using PPG system on my 70. Using the DPLF50. Heard the K36 is a no-no with acrylic lacquer.Think the Kondar acrylic prime/surfacer may be the way to go with the lacquer finish. Any thought?Comment
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Re: Repainting Fiberglass
Dennis, there are plenty of guys here that know more about lacquer than I, but it APPEARS that Kondar CAN be used under acrylic lacquer according to the product sheet (see link).
You'll need to read the product sheet carefully yourself. Sometimes there are little requirements in semi-fine print that can bite you if you don't follow directions. I would also confirm that I could get the PPG acrylic lacquer before I committed to a system. I think the lacquer probably out there...you could try AutoColorLibrary if local distributors can't mix the color you need.
Kondar DZ Acrylic Primer SurfacerComment
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