[paint guy]

After reading the above posts,it seems there has been a reasonable degree of success using single-stage paint vs BC/CC on enduras.When I get the panels from Paul,I will run film thickness and then spray similar panels using a single-stage(Centari,or PPG's or sikkens, whatever we have laying around in the lab)and throw that into the mix.I'm getting ready to spray my endura within a couple of months,so I'm curious like everyone else as to what a good system(s)is.Half-inch-studart of the testing will be adhesion(cross-hatch type test)run on rubber that hopefully will closely simulate Endura material.At the least,if a paint type or two stands out adhesion-wise(good or bad)we should find it.

[Half-Inch Stud]

Paint-Guy: Here'ss a hunch: ME thinks PAINT sticks super-well to endura without need for primers?

[jpdog357]

Any update on this?

[Jack Ferris]

Ok I have read everything there is to read about prep/paint on the endura front bumpers. I will share this story. 22 years ago I did a repaint on the bumper of my 69 GTO (really a LeMans) bracket car. Back then the only exposure to body/paint besides watching my father do it is I did some "intern" work at a body shop. Mainly block sanding and sweeping. It goes like this. I stripped the bumper with Aircraft stripper. Washed it off with soap/water. I then sprayed it with PPG's K200 and the flexible catalyst. Blocked and did it again. Once it was strait I shot it with PPG's Delstar paint and used the same clear. Used SEMflex in both base, which really wasnt base it was a single stage paint and the clear. Now I must say I got an ear full from the guy I interned for saying I used all the wrong materials on it. Well the bumper ran on my car for 10 years before switching to a glass nose. It sat in my basement for another 9 years and then I scuffed it, shot it with a single stage urethane and it is now on my 69 Judge, where it has been for 3 years and still, not one single crack. Theres no way in hell I would use that process over again but to date its still working. Just thought I'd share.

[Jack Ferris]

Something else I was wondering. Some have mentioned V-ing the cracks and filling them. Right now Im doing the prep work on a 70 T/A front bumper. It's very clear to me the cracks are just that. Cracks. But, when all the paint is removed, which it has been, you can see "spider web" marks that followed the pattern of the old cracked paint I stripped off. Kind of like a deterioration of the undura from the paint cracking. To me these don't really need to be beveled and filled. I could be wrong but if they wont fill with primer I will have more filler than endura on this bumper by the time I'm done. Any advise?

[Formula8]

I hope you are right too. I took mine down pretty far with a DA and 90 grit to where they were barely visable if at all. I then skim coated over the entire area with the 3m flexible parts repair. So far so good.

[Formula8]

Originally Posted by jpdog357

Any update on this?

Not that I know of. I think it died on the vine. If Paul doesn't have the time, I wouldn't mind getting the $80 in rubber back so I can spray some myself. More curiosity than anything else cause I am pretty well set for materials at this point. I had a set back on another part of the car otherwise I would have painted my bumper by now.

[paint guy]

To date,i have not recieved any metal or rubber parts to test.When they are recieved,I will test ASAP and post results.

[goatman-68]

I am getting ready to paint my Endura and have a question. I tried sandblasting my endura today and it wasn't working well so I ended up DA sanding the whole thing with 80 and sandblasted the back side. The bumper was painted 25 years ago with lacquer and a lacquer clear coat. My question is, do all traces of the lacquer need to be gone when using urethane primer?? I was going to use the SPI primer but no one in my area carries it so I will be using the Mar-Hyde urethane that I used on the rest of the car.

[70 One Owner GTO]

I finished all the body work on my TA and brought in a painter to shoot BC-CC 2 weeks ago. A week before that my painter wasn't satisfied with my '70 TA bumper and after saying that he had repainted 3-4 endura bumpers in the past with good results, he took my bumper to his house so he could work on it in his spare time. He brought the primed bumper to my shop when he came to shoot the car. The bumper had two cracks in the primer (PPG urethane) when he arrived and he swore it was good when he left his house. In the two weeks since then the bumper has cracked in 6 other places. I sanded cracks down to the rubber and cracks were in primer only.
I have been following this thread for almost 7 months so that I could paint this bumper without failure like just happened. If PaulatFast doesn't have the time to do what he volunteered to do almost 7 months ago maybe he will give the test strips back so that someone (PaulatSlowasHell?) could paint these so that the Pontiac community would have some guidance.
It would be much appreciated.

[goatman-68]

Today I spoke to a friend of mine thats been a body man forever and he pretty much told me to get rid of all the lacquer. I asked him how he would prep. He stated that he would start with a seal coat of Epoxy followed by two medium coats of 2K, block and shoot with B/C, no flex in anything. So I am off to the paint store for some SEM two part repair and continue stripping to the rubber.

I don't see any reason to use adhesion promoter since I am going to use epoxy over the bare rubber...........

[PaulatFast]

HOLY ****! Holy ****! holy ****! I dropped this ball big time! The rubber and the tin are still in my paint room up top on a shelf... life kind of got in my way and I forgot all about this! I'm still game to try it. Can't freakin believe I gapped this. Sorry guys. Someone should have called me, I was without a computer for awhile...

[notime]

A baby wouldnt have anything to do with it would it?

[GT182]

Hope you use the flex agent for the paint on the endura bumpers. The nose on my 79 Formula had to be repainted when the rest of the car was done. The painter forgot to add the flex agent and had to repaint it over again. Without it the paint will crack like crazy if you push on the bumper or it gets hit.

[Formula8]

My bumper is painted and flex was used. It's only about 10 degrees in my garage right now and my lights will barely turn on but I will try and get some pics up. It looks great but will it hold up us the question.

[goatman-68]

Well, I just painted mine and did not use any flex. I did however use BullyDog adhesion promotor on the bare rubber before I primed with 2K urethane.

What I was told is that the (flex agent) is not permanent, it goes away after a short peroid of time. I was also told that it is used if the bumper is off the car and is used to give the paint some flex when installing and tightening to the brackets. My bumper was test fit first and had no stress on it while installed. I will be putting it back on the car this week.

PPG told me no flex is required with the 2002 clear.
Mar-Hyde also told me no flex was required with their Urethane primer.

I just kept the primer & base to minimal thickness and will hope it survives.........

There are many opinions of what is proper or not.

On another note, I painted this same car over 30 years ago with red lacquer and a lacquer clear coat. After 30 years the paint was still nice and no cracks on the bumper...................... The car did not see alot of sun though........

[Jack Ferris]

Again, flex additive is only good for about 30 days to allow for reassembly. The paint will eventually harden. GTO Endura as well as FB can me prepped as normal and painted just the same. If some a$$wipe pushes hard enough on the edges or it gets twisted while installing its going to crack.

[Formula8]

Not sure if I am totally buying the temporary flex on every manufacturer's products. I had the same painter paint my spoiler welting 2 months ago. He had to order something he called super flex from Glasruit. I can still tie the welting in a knot and it does not show any signs of cracking. Next week I will drop him a line and ask him what he used.

[Formula8]

Some pics. Sorry for the poor quality. Sometime when the temps get back to reasonable I will get some real pics posted. It looks better in person.

[paint guy]

Originally Posted by Formula8

Not sure if I am totally buying the temporary flex on every manufacturer's products. I had the same painter paint my spoiler welting 2 months ago. He had to order something he called super flex from Glasruit. I can still tie the welting in a knot and it does not show any signs of cracking. Next week I will drop him a line and ask him what he used.

There are many different types of plasticizers (flex agents) available to paint formulators (and other industries) and differing chemistries will behave differently. Some will evaporate/volitilize/migrate to the surface after a period of time. This type is commonly used for late-model collision work as a bumper cover, for example, and only needs to have a large degree of flex until installed. Other, more permanent types of plasticizers (polyester, for example) may retain flexibility for a much longer period of time and may be more suited for an endura bumper or spoiler welting, for example.