I'm doing a color change on my GT, (Gold to burgundy, the car has already been primed in Black) I want the body side moldings the Same color as the car. Do I need to Sand / Prime, Paint, OR just Sand and Paint the moldings? (Base clear, the moldings have never been painted before) Thanks for educated oppinions. ... Roger ?
I would scuff and prime. You never know if anyone has ever applied a dressing to them. Silicone dressings will cause fisheyes, and pealing. Besides, what's it gonna take, 1-2 hrs max to prep them out? If you don't prep, and they peal, you now have to go back and sand/prime, then pay someone to re-apply the color.
I went the same route when I painted mine for a second time. I would definitely recommend priming them first to promote maximum paint adhesion. Considering the height of the fiero, those side moldings can take a lot of door dings in parking lots (I know mine have). Priming the moldings could potentially help keep your paint from chipping when some jerk swings his SUV door open.
------------------ "The Twins" '87 GT 3.4 pushrod daily driver '88 GT 3.4 DOHC swap in progress
I remember having the thick, black side moldings on my '90 Mustang painted body color because in '91 they came from the factory color coded and it looked so much better.
The body shop guy told me they would use a primer with extra "bite". Not sure what that means but after 5 years there was no chipping or peeling.
You need to use a special plastic primer - one that melts into the plastic, then prime with regular primer (I use PPG DP epoxy primer) & paint. http://gafieroclub.org/bbs/index.php?topic=469.0 ~ Paul aka "Tha Driver"
urethane over fusion would probably work, I would just avoid lacquer and fusion as the fusion paints tend to be on the soft side and don't handle solvents very well.
------------------ "The Twins" '87 GT 3.4 pushrod daily driver '88 GT 3.4 DOHC swap in progress
Basecoat/ clearcoat is the most durable paint, but just remember that if anyone bangs their door edge in it, it will chip down to the original color. Even factory painted ones do. I dont know specificly what plastic is used for the Fiero moldings, but many factory parts I get like moldings and bumpers, etc, dont use any kind of primers at all. Its just scuff the plastic and paint. ie/ I just did a new OEM side molding for a newer BMW. Instructions specifically said scuff with scotchbrite pad and paint, after thorough wash with soap and water and prepsol.
In 2011 I painted all the urethane parts of my 2nd gen trans am. I followed ppg's instructions to the T and couldnt be happier. Its still very flexible, no cracks and is very stone chip resistant. They call for an adhesion promoter on bare plastics then flexible epoxy primer followed by your top coats mixed with flex additive. If its in your budget its worth it. I dont remember the specifics but all their info is on their website. When I paint my fiero I am doing it the same way.
You just been lucky no ones hit them yet Jimmo. A few things in my opinion as a 50 year professional. Adhesion promoter really has very little effect. Ive done my own tests on old parts. Flex additive dont do anything for side moldings that dont ever flex anyway when installed...It also never worked on GTO flexible bumpers that it was originally designed for. Besides, it evaporates out within a few weeks anyway...so its not 'still' there. The best it was ever good for was like urathane bumpers where it kept the paint pliable long enough to get them mounted with the bending and twisting. My opinion is your parts are still good because they havent been hit yet, and the newer basecoat clearcoat systems are somewhat pliable all on their own without any kind of additives. The best adhesion comes from proper prep, not magical additives. If someone opens their door into the moldings on your car, it has to chip the paint, and the original plastic will show. Factory colors are put on with a lot different process than any body shop does them.
I'm Scuffing them, very lightly after washing, then "undercoating/priming" them with the same color (Burgundy) FUSION, then scuffing and Burbundy Base/ Clear. If the base clear does ever "chip", at least what will show will be "pretty much " the same color, not gray or black. Here's hoping.
sounds like a reasonable plan. Good luck. I have never used Fusion, so I dont know how well it performs. Since it is designed specifically for plastic, Id assume its pretty durable. I also dont know how regular paint adheres to it either. If you get add on side moldings for new Corvettes, most colors require a white basecoat first. Like I said basecoat/ clearcoat is pretty durable on its own, but I have seen them chipped down to the white or bare plastic. Other peoples door edges are pretty destructive. If I have to repair a car that has factory colored side moldings, I try to order them in the correct color since its more of a vinyl coating than a paint from the factory. Cadillac is nice about offering prefinished moldings.
I've used Fusion on alot of household thngs. Plastic molding in the Base of a shower, they have been standing up to Bleach and all sorts of detergents for 5 years now, No chipping, peeling or discoloration. That was just wiped down with wax and grease remover and Shot ! not even sanded. Amazing stuff. I know it'll never come off the side moldings, Maybe the Base/clear will chip, but this stuff won't.
You just been lucky no ones hit them yet Jimmo. A few things in my opinion as a 50 year professional. Adhesion promoter really has very little effect. Ive done my own tests on old parts. Flex additive dont do anything for side moldings that dont ever flex anyway when installed...It also never worked on GTO flexible bumpers that it was originally designed for. Besides, it evaporates out within a few weeks anyway...so its not 'still' there. The best it was ever good for was like urathane bumpers where it kept the paint pliable long enough to get them mounted with the bending and twisting. My opinion is your parts are still good because they havent been hit yet, and the newer basecoat clearcoat systems are somewhat pliable all on their own without any kind of additives. The best adhesion comes from proper prep, not magical additives. If someone opens their door into the moldings on your car, it has to chip the paint, and the original plastic will show. Factory colors are put on with a lot different process than any body shop does them.
Roger, No disrespect but I couldnt agree LESS. I dont claim to know a lot and Ive only used PPG products. Your methods may work with the paint you use but I also did my own tests after ruining some fiberglass motorcycle parts by painting them your way(without flex additive). I listened to advice from the guy at my local paint shop selling me the stuff. He too said it wasnt necessary to add flex for exactly the same reasons you described. That was 12 years ago and after all that work and money spent I will never listen to advice that goes against what the manufacturer recommends. If you read the tech sheets it states that the paint will remain flexible.....its not just for assembly. By the way the front fairing cracked within a few days while installing it, multiple cracks where the mirrors mount. It didnt come off, just cracked. There was NO problem with adhesion. When I painted my car I also sprayed 4" x 14" pieces of plastic back in 2011. The one with flex additive can still be rolled into a circle without the paint cracking. Im normally a lurker and learn a lot here just reading but I dont want to see a newbee lurker read your post and waist hundreds of dollars and hours taking on a huge DIY paint project and have to do it twice because they wanted to save 30 dollars on flex additive. All that to say, if the manufacture recommends I wouldnt try to skimp out.Sorry for rambling but I hope it helps someone. By the way I have used fusion and that should work out well. I just hope its receptive to what is going over it.
ok, go with what works for you. I use Sherwin WIlliams and BASF/RM paints myself. First you never would need flex agent for fiberglass, its not flexible like a urethane bumper is. I talked to a guy that works for the company makes a flex agent at the Goodguys Car show, and he was only one of the people who have always told me it evaporates out of the paint after a few weeks. I paint my own show cars and street cars as well as hundreds of others and I havent used flex since 1970. Ive never had a bumper crack or peel that hadnt been in an accident...which would need it redone anyway or replaced. I friend of mine owned a company in Lancaster that coated urethane bumpers for GM factories in the 70s & 80s by the semi truck load. Those were not painted at all, and Im assuming they use the same process now...but maybe not. I do get lots of brand new OEM plastic parts for higher end cars like BMW and Mercedes that the instructions that come with them just say scuff and paint. When GTOs were new in 69-70s with the Enduraflex bumper, they came up with the flex agent as an additive to go with the then used GM lacquer. Every GTO I redid with it cracked back within a month after being stripped of cracked factory paint, so I stopped using it at all. Funny thing was they didnt crack unless hit. All I can say is what Ive experienced myself doing cars for 50+ years. Everyone also says you cant use lacquer primers, but Ive not had a single problem in the thousands of cars Ive worked on with it, including my own. So I take anything the factory experts say with a grain of salt.
