stock76

Got all the original lacquer paint stripped off, bonding seams,etc., done. Block sanding and primer coats ready for paint.

The more I looked at the original urethane bumpers the more I realized they were not going to cut it with the new paint job both in looks and longevity.

I went with the Tru Flex Bumpers from Wilcox.

I have the rear cover pretty well fitted. The passenger side is good but the drivers side is about 1/8" too short on the side. I can pull some of it in with the quarter panel and the mounting bolts. Whats the best product to use to fill the bumper side? I have Evercoat SMC Resin and mat, Evercoat Polyflex, and Evercoat Rage Gold on hand. I used up all my Vette Panel Filler on the bonding seams and as filler on some areas on the car (Great stuff!).

Instead of filling the side, is it possible to adjust the inner bumper from side to side and "split the difference". I know there is vertical up and down adjustment on it. I could live with that as it would be at least as good as the original urethane was.

Also, I have read reference to "modifying" the bumperettes if the cover does not fit over them. I assume this applies to the inner bumpers on either side as well as the two bumperettes on either side of the license plate What modification works? elongating the mounting holes for more adjustment, cutting, or grinding, or discarding them altogether?

Last question: Priming and painting. Do I need to use a flex additive or adhesion promoter (Bulldog) on these bumpers? They are not nearly as flexible as the originals. I plan to use Nason 2K Urethane Primer and Nason base and clear to paint the bumpers (and the rest of the car)

Hope this wasn't too long. I was a little surprised that the instructions that come with these bumpers isn't more detailed with tech tips, etc.

I'd also like to thank Dub for all the help he gives everyone on this forum. Although I haven't asked for his help directly, researching and reading his posts here have helped me a great deal. Dub, you ought to take all your forum posts and put them together in a how-to book.

DUB

I have a book in the 'works'. I apply time to it when I have time and the mental capacity to do so.

As for your flex bumper. I use rigid fiberglass bumpers only..... so...in this case...due to the bumperettes possibly holding the bumper in place in regards to the side to side movement. If you do have some side to side movement but it does not allow you to split the difference...then the impact bar needs to be loosened and moved so you can split the difference. Because slotting the holes may not do anything if the bumper is being stopped by the bumperettes or brackets at the license plate area.

Seeing how I prefer the rigid fiberglass bumpers for a few reasons...I use Vette Panel Adhesive to do any building up when I precisely fit the bumpers to the body.

SO...if you choose not to buy some more for that little bit of area...then what you use is up to you. And if you read my previous posts..I think you know how I feel about VPA when compared to other fillers.

AS for painting...even though these may be called 'flex' bumpers....they are not flexible like urethane so you really do not have to add a elastrometric additive....but if you want to it will not hurt anything if you choose to go that route.

It was hard to tell if you are doing the front bumper also....because all I wrote was for the rear. If you need help in the front...reply and let it be known. Because the front is REALLY FUN....and you may find you may need the VPA due to the bumper just does not want to fit right.

DUB

stock76

Dub, thank you! I got all the bolts snugged up to see how everything fits. Its not bad and probably about as good as the urethane bumper was. I may try adjusting the impact bar to see if that evens out both sides or if I still need to use a little filler. I don't think slotting the holes will do much if anything because it appears the bumperettes will not allow the movement. Doesn't look like much wiggle room.

I did not know exactly how much difference there was between the fiberglass bumpers and flex bumpers. I understand what you are saying about the fiberglass. The "flex" bumpers really don't flex all that much. Looks like the ones I got are pretty good overall though. That, plus the fact that outside of a little bump on the front driver's side that put a small crack in the side of the front fender (years ago), my car has never been hit probably helps.

Yes, I'm doing the front too. Its next. If I need any serious filler I'll go get another quart of VPA. I did use it filling chips and dings as well as the bonding seams. That stuff sets up like steel and won't come off anything once it cures. I learned that timing is everything when using it. You better work it while you have that short window of opportunity or......

Thank you again Dub. If (Ha!, I mean when) I run into trouble on the front bumper I'll be hollering help for sure.

Gary

DUB

Gary,

If you center the bumper and this causes you to have to build out on each area of the bumper by where the bonding strips are on your quarter panels...I understand.

The main reason I like the rigid bumpers is that they are obviously more rigid and way back in the day when there was NO 'flex' bumpers...and all there was was rigid fiberglass bumpers..I have gotten used to doing them and I am not impressed with the flex bumpers. I have only put one on and it will be my last.

I assume you have removed the taillight supports that were bolted to the impact bar??
I also go in and take out the shims between the impact bar and the absorber if I am still having binding issue.

I AGREE...the KEY thing to know about using VPA is making sure to work it while it is setting up...along with many other things to know. IF you let it sit...it becomes rock had and can be a bit more labor intensive. It TRULY is some awesome adhesive/filler!

DUB

stock76

Dub, that is exactly the area I need to build up on both sides of the rear bumper. Fortunately not too much.

Yes, I removed the tail light supports. The TruFlex is rigid enough to support the tail lights. I can see where trying to use the supports may cause stress on the bumper cover possibly deforming it a bit. I didn't have to remove the shims but did loosen the bar and adjusted it down very slightly and got a better overall fit.

Working on the front now. It fits over the honey comb with just a little coaxing. I had to shape the front radius corners between the headlights to get a better fit.

Biggest problem so far is the drivers side where the previous owner dinged the front corner into one of those low concrete parking polls. Passenger side lines up pretty good, but drivers side has a gap on the side that starts at nothing to about 1/4" wide and then back to nothing. The gap starts about 1/3 of the way down the fender. The old urethane bumper fit with no gap there. Other than seeing where the body man patched the 2" crack and bondo'd over it to smooth it out I can't see anything out of line. It all looks original. The crack runs just above the side light from the front of the fender in about 2". I didn't want to buy a whole quart of VPA for that little bit so I built it out with the Evercoat SMC resin and mat that I have.

So far so good. Thanks again for your advice. After working on Corvettes all day I appreciate your taking more of your time to help me and the others on this forum by sharing what you know.

DUB

I can say that I WOULD NOT use this stuff...I have had nothing but problems with it and will not use it at any cost. Maybe Soyuz are better than I am and getting it to actually bond. I tied numerous times and I could literally POP off my lamination with a thin screwdriver.

DUB

stock76

I haven't used it extensively but so far so good.

The bond seems strong where I have used it. No special prep, just roughed up the area with some 80 grit, blew the dust off wiped it down with degreaser, dipped the mat in the resin and laminated. I did learn that it is sensitive to the amount of blue cream hardener used. Use even a fraction too little and you get a long set up time and poor bond. Playing with it I found if you used too little hardener you could force cure it with heat and it would get hard but the bond was extremely weak and you could peel it back off

Maybe Evercoat has done like most chemical manufacturers do and continually tweaked the formula. That, or I got lucky, or in a month it will fall off and I'll have to do it all over again (I sure hope not).

DUB

I know that the SMC resin from Evercoat that I was getting had a white cream hardener...which I feel does not matter...but that is what I always got when I bought it....and the chemical make up of the hardener may be different or has changed.

I hope it works for you. I have sworn it off and will never use it again...only because I have been burned by it NUMEROUS times.

DUB

stock76

Dub,

Evercoat SMC Resin now uses the same blue cream hardener that they use for their VPA, Rage body filler, Polyflex body filler and some of their other products. Must be some common ingredients in all of them now. Maybe they have changed the formula. I sure understand what you are saying though. If a product doesn't work stay away from it and use what you know works. Maybe their resin is good now (I hope) but if you have a system that works for you why take a chance. You have customers and a professional reputation to take care of.