[PaulatFast]

Joe it seams like I have a part time job explaining how we prep and paint Endura bumpers! lol!

I own a rstoration shop that specializes in GTO's, 68-70's in particular. Having owned and worked on these cars since 1983, the endura issue is one I am more than casually aquainted with. The method I am about to outline was established by myself through trial and error, asking ALOT of questions, and doing some unorthodox testing over the years. Since I have been following this proceedure, I have not had any issues with endura Bumpers paint cracking, lifting, bubbling, shrinking... whatever! In 2007 I met Barry Kives, owner of Southern Polyurethanes Inc, and the smartest and most knowledgable painters that i have ever met! I call him regularly for advice and he always has the answers. After questioning him about endura, I was shocked to find out he actually knew what it was! He also had painted several GTO's with that rubber material hanging on the front. Hs proceedure and his results mirrored mine. Based on this information, I am willing to stand up and state my way of repairing, prepping and painting these noses. One thing I will add before getting to the repair, unlike some of my peers, who do cars that are kept in climate controlled garages, or sent to an auction soon after completion, alot of my stuff is exposed to the elements. My judge was painted in 2007, car sat out all last summer. I put it in very damp uninsulated storage in mid Dec. after it sat out in the cold until then. It looks like the day it was painted.

We sandblast the noses down to bare rubber. It is very important to keep the nose clean and free of any oils or silicones, the rubber can act like a sponge and it seems to never come clean once it is oil soaked...

We do not use adhesion promoter. Ever. IT IS NOT NEEDED. The two part FLEX Epoxy repair material sticks to the bare endura better than you can imagine, no need to add anything into the mix.

All repairing and shaping is accomplished with the flex epoxy two part filler. We shape with 80 grit, followed by 180. The stuff sands well and sticks to the endura so well that it easily feather edges back to the bumper.

No filler primer. No filler primer. NO FILLER PRIMER!

The only primer I use on the noses is SPI epoxy. It doesn't harden, yet is totally sandable. We spray three coats of Epoxy allow it to dry for a day, then block with 180. any repairs are made with the two part flex epoxy, then the nose is shot again with 3 coats of epoxy. That is sanded with 320 to get the peal down, then 400 and finally 600 prior to paint.

If you want to use any other manufacturer's epoxy primer, that's up to you. I cannot tell you if it will work or not. If the epoxy stays pliable and sands well, I'd guess you'll be ok.

We don't use any flex agent in the base. After looking into what the flex agent actually does, which is simply retarding the drying time of the paint, I decided that was not what i wanted going on under my clearcoat. Seamed like a perfect reason for the clear to lift as the base cured out over time. I'll pass!

We don't use any flex agent in our clear. We spray SPI Universal High Solids Clear. It never seams to fully harden. It will sand and buff the same after a year as it does after a day. It remains pliable. I have used other high end clears that stayed pliable as well. Cheap clears seem to harden after a few days or weeks. Would flex agents help those clears? At least temporarily, I'd guess. keep in mind flex agents are temporary in most cases.

There you have it, my way of doing these noses. If followed exactly, I would be suprised to find out you had issues. Good Luck.

[dataway]

Paul, we need to get your process put into a Stickey up at the top of this section. Might save you some typing time
JohnnyB

[hobi]

Originally Posted by PaulatFast

Joe it seams like I have a part time job explaining how we prep and paint Endura bumpers! lol!

I own a rstoration shop that specializes in GTO's, 68-70's in particular. Having owned and worked on these cars since 1983, the endura issue is one I am more than casually aquainted with. The method I am about to outline was established by myself through trial and error, asking ALOT of questions, and doing some unorthodox testing over the years. Since I have been following this proceedure, I have not had any issues with endura Bumpers paint cracking, lifting, bubbling, shrinking... whatever! In 2007 I met Barry Kives, owner of Southern Polyurethanes Inc, and the smartest and most knowledgable painters that i have ever met! I call him regularly for advice and he always has the answers. After questioning him about endura, I was shocked to find out he actually knew what it was! He also had painted several GTO's with that rubber material hanging on the front. Hs proceedure and his results mirrored mine. Based on this information, I am willing to stand up and state my way of repairing, prepping and painting these noses. One thing I will add before getting to the repair, unlike some of my peers, who do cars that are kept in climate controlled garages, or sent to an auction soon after completion, alot of my stuff is exposed to the elements. My judge was painted in 2007, car sat out all last summer. I put it in very damp uninsulated storage in mid Dec. after it sat out in the cold until then. It looks like the day it was painted.

We sandblast the noses down to bare rubber. It is very important to keep the nose clean and free of any oils or silicones, the rubber can act like a sponge and it seems to never come clean once it is oil soaked...

We do not use adhesion promoter. Ever. IT IS NOT NEEDED. The two part FLEX Epoxy repair material sticks to the bare endura better than you can imagine, no need to add anything into the mix.

All repairing and shaping is accomplished with the flex epoxy two part filler. We shape with 80 grit, followed by 180. The stuff sands well and sticks to the endura so well that it easily feather edges back to the bumper.

No filler primer. No filler primer. NO FILLER PRIMER!

The only primer I use on the noses is SPI epoxy. It doesn't harden, yet is totally sandable. We spray three coats of Epoxy allow it to dry for a day, then block with 180. any repairs are made with the two part flex epoxy, then the nose is shot again with 3 coats of epoxy. That is sanded with 320 to get the peal down, then 400 and finally 600 prior to paint.

If you want to use any other manufacturer's epoxy primer, that's up to you. I cannot tell you if it will work or not. If the epoxy stays pliable and sands well, I'd guess you'll be ok.

We don't use any flex agent in the base. After looking into what the flex agent actually does, which is simply retarding the drying time of the paint, I decided that was not what i wanted going on under my clearcoat. Seamed like a perfect reason for the clear to lift as the base cured out over time. I'll pass!

We don't use any flex agent in our clear. We spray SPI Universal High Solids Clear. It never seams to fully harden. It will sand and buff the same after a year as it does after a day. It remains pliable. I have used other high end clears that stayed pliable as well. Cheap clears seem to harden after a few days or weeks. Would flex agents help those clears? At least temporarily, I'd guess. keep in mind flex agents are temporary in most cases.

There you have it, my way of doing these noses. If followed exactly, I would be suprised to find out you had issues. Good Luck.

I would agree 100 percent with Paul I have been working on these bumpers since 1978 and through trial and error I have a system that mirrors the one mentioned above. I am no chemist but through the years I know what does not work. NO FILLER PRIMERS NO FLEX AGENTS.

The first thing I do is straiten the bumper most of them have been hit so I make sure they are strait sometimes I have to use a hydralic press then I sandblast, than I mount on the car with the fenders bare metal, I then do all my repairs with sem flexible repair kit part number 39768 and fill both sides of bumper till it completely touches fenders, than I carve the rubber kit and shape with 60 grit than 120 grit than 180 grit than this is where my system changes a bit from Pauls and only because I cant get SPI nor have I ever heard of it, I than shoot three to four coats of PPG DP 48LF Epoxy Primer with their DP401LF Epoxy Primer Catalyst than I wait two days and I block it with 120 grit fix the bad spots with the SEM KIT then I shoot three to four more coats of PPG DP Epoxy, I wait two or three days and sand with 320 wet than 400 wet than 600 wet if any little bad spots show up I repair and spot prime with PPG Epoxy than wet sand and finish with 600 wet.

I than begin paint process which cosists of the following, I usually use Lacquer and I have to thin 200 percent to get it to flow, but the Basecoat system is almost the same I shoot the color on the bumper WITH NO FLEX AGENT AS PAUL MENTIONED NONE IS NEEDED AND HE IS 100 PERCENT RIGHT. I shoot 4-5 coats I do however put just a little Catalyst in the basecoat. I let it sit a couple of days sand the orange peel out with 400 wet and then I finish with 600 wet this is where you start to see all your hard work pay off. I shoot another 4-5 coats depending on the color and if everything lays down nice I shoot 4-5 coats of Matrix MS-42 Clear with MH-008 Very Slow Hardener Its summer in Phoenix Arizona and the lowest the temperature goes when I paint is in the 90,s 115 during the day. I let the Clear sit for a couple of days then I sand with 600 wet and shoot another 4-5 coats of clear wait a couple days than I sand with 800 wet than 1000wet than 1500 wet than 2000 wet than 2500 wet than polish. If you dont want to clear twice than put as much as you can on once and sand and polish but I usually clear twice.

Anyway thats my system and I can say it works for me 6 cars no problem as of yet its a little different than Pauls but it is tried and proven, and some of these cars are in extreme heat 117 degrees plus at certain times of the year and so far so good.