87-88 coupe front bumper repairs (Page 1/1)
cartercarbaficionado AUG 20, 10:43 AM
been fixing this poor condition bumper I got for free and I think it's turning out ok. still have some fiberglass work to make the 2 major missing parts (license plate is a filler peice to help me get the fiberglass to stay in place and maybe to help strengthen that area of repair depending on how much fiberglass and short strand filler i need to make it all disappear) to repair the chunk missing out of the lower ducts but hey it was the best I could get within a state or 2. as it turns out normal fiberglass and resin for boat repairs (long story) sticks very very well to urethane and will flex slightly with it. I definitely should find a more flexible resin but the worry is not having the proper adhesion at that point since most of those are expensive and really made for a corvettes more solid bumper.
Yellow-88 AUG 20, 03:28 PM
Looks like you have your hands full with that one. you may want to consider building a fixture to hold it closer to it's final shape while you work on it.

You have some pretty nasty concave areas above the trim line. That's really common and seems to be accepted. Long ago I started a project to make a hard fiberglass piece to replace that section. Of course one needs a brand new one to make a mold, or a a mold made from scratch so ..... it's on hold.
cartercarbaficionado AUG 20, 04:55 PM

quote
Originally posted by Yellow-88:

Looks like you have your hands full with that one. you may want to consider building a fixture to hold it closer to it's final shape while you work on it.

You have some pretty nasty concave areas above the trim line. That's really common and seems to be accepted. Long ago I started a project to make a hard fiberglass piece to replace that section. Of course one needs a brand new one to make a mold, or a a mold made from scratch so ..... it's on hold.


that's because it's not mounted. when this was mounted on a car a few weeks ago it was fine and looked really good until we took it off and the cracks got bigger. on the bright side though I pretty much can't make this one worse ao the way it's been held together is with drift stitches then fiberglass.
Yellow-88 AUG 21, 12:56 PM

quote
Originally posted by cartercarbaficionado:

that's because it's not mounted. when this was mounted on a car a few weeks ago it was fine and looked really good until we took it off and the cracks got bigger. on the bright side though I pretty much can't make this one worse ao the way it's been held together is with drift stitches then fiberglass.



I'm referring to the area above the trim line. Mounting it won't change that. The plastic distorts over time in the sun. It's supposed to be convex, not concave like most become. I put ribs on the back side to hold it's shape but even they want to distort over time. That's why I was considering a hard fiberglass piece. Please excuse the scars on yellow's nose. He's not a weenie and is not afraid of the road.

[img]C:\Users\Computer One\Pictures\88-Nose[/img]
Yellow-88 AUG 21, 12:59 PM
So ... how does one get a picture to post?
longjonsilver AUG 21, 02:58 PM

quote
Originally posted by Yellow-88:
I'm referring to the area above the trim line. Mounting it won't change that. The plastic distorts over time in the sun. It's supposed to be convex, not concave like most become.



i repaired mine with compound from Canadian Tire that is made to work with flexible bumper covers. Fiberglass is rigid and not a good idea imho.

i used foam sleeping bag mat material to stuff the area under the bumper cover and the metal, that way it put continual upward pressure on the bumper cover to prevent it from concaving. Still i have some concavity on the left side, so use more than you think you shud.

------------------
Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 3800SC, 4-wheel drifts are fun!

cartercarbaficionado AUG 21, 03:02 PM

quote
Originally posted by Yellow-88:


I'm referring to the area above the trim line. Mounting it won't change that. The plastic distorts over time in the sun. It's supposed to be convex, not concave like most become. I put ribs on the back side to hold it's shape but even they want to distort over time. That's why I was considering a hard fiberglass piece. Please excuse the scars on yellow's nose. He's not a weenie and is not afraid of the road.

[img]C:\Users\Computer One\Pictures\88-Nose[/img]



yes I know where it distorts. thus bumper doesn't have that yet since it was inside a barn most of its life. when fully mounted its 20x better than the aero nose I took off
Yellow-88 AUG 23, 09:15 AM

quote
Originally posted by cartercarbaficionado:


yes I know where it distorts. thus bumper doesn't have that yet since it was inside a barn most of its life. when fully mounted its 20x better than the aero nose I took off



It's very obvious in the picture. If you see it when it's dismounted, it's there.
Of course it's only important in a 100 point judged show. Contouring and block sanding is very difficult on a soft bodied car and some judges can be somewhat forgiving, but a concave nose is hard to overlook. I do understand that not all Fiero's are show cars. That's a whole different animal.
Yellow-88 AUG 23, 09:57 AM

quote
Originally posted by longjonsilver:


i repaired mine with compound from Canadian Tire that is made to work with flexible bumper covers. Fiberglass is rigid and not a good idea imho.

i used foam sleeping bag mat material to stuff the area under the bumper cover and the metal, that way it put continual upward pressure on the bumper cover to prevent it from concaving. Still i have some concavity on the left side, so use more than you think you shud.



Most auto body supply firms offer a similar products to what you used. Yes fiberglass resin on flexible plastic will eventually show up. The expansion coefficient is different than the flexible nose piece. I have used it to reinforce the back side but not on visible areas with finish paint over it.

I do like the stuffing idea. Does it end up being ridged enough to contour sand?

My idea of replacing the section above the molding on the noses that have a molding with hard fiberglass was to allow for contouring. The deck lid and that piece would be equally ridged so doing a "perfect" blend would be possible. That really can't be done on the aero nose because there is no molding. I used ridged foam insulation shaped to fit under Sweeties 87 GT. It was stiff enough to actually contour the nose.