Fiberglass Rear Bumper Fitment

[obscene]

Hi all,

I'm hoping you can help me with a few quick questions regarding fitting my fiberglass rear bumper. I typically see fitment issues in the arches, so I'm not sure how to address what appears to be my problem.

1. I can't seem to find any pictures of these bumpers installed without the seals and taillights. Is the gap between my "bumperettes" and taillight housing normal?

2. If not, how would one go about closing that gap?









Finally, do you think I should cut half moons above the pipes for heat relief?



Thank you!

[advtracing]

Following as mines just as bad

[michaelaiellosr]

Fiberglass auto parts....yuck! (Regardless of who makes them). Having said that the nice feature about frp, with a little practice using epoxy, glass fabric and filler, you can always fix it. West Marine has a kit and instruction booklet that helps a great deal for those willing to try. Never had a piece that didn't require trim, cut , layup reinforcement along with some sanding.

[76911S]

Sorry, but that looks terrible. The only way to fix that will be a lot of cutting and rebuilding. I would source a different bumper. Mind fit kinda like that, I spent a ton of time making it work and I am not happy with it. Now after paint, it looks bad and has already started to crack. I will be replacing it sometime and that just adds up to more $ now. Should have bought a new one before painting.

To answer your question, no that is not normal, the bumperettes should be parallel and fairly snug.

Mark..

[obscene]

Sorry, but that looks terrible. The only way to fix that will be a lot of cutting and rebuilding. I would source a different bumper. Mind fit kinda like that, I spent a ton of time making it work and I am not happy with it. Now after paint, it looks bad and has already started to crack. I will be replacing it sometime and that just adds up to more $ now. Should have bought a new one before painting.

To answer your question, no that is not normal, the bumperettes should be parallel and fairly snug.

Mark..

Thanks, Mark. The bumper is from a highly regarded source which leads me to believe the whole fiberglass market is a crap shoot. The budget is already blown so maybe it's time to price out steel bumpers...

[chris_seven]

Thanks, Mark. The bumper is from a highly regarded source which leads me to believe the whole fiberglass market is a crap shoot. The budget is already blown so maybe it's time to price out steel bumpers...

I have to disagree but do understand your frustration.

The problem with many of the fibreglass bumpers being sold is that the moulds are poor due to lack of time spent preparing the buck that was used to make the mould.

The poor shape of the bumper guard is typical and the 'droop' of the top face where the seal sits is also typical.

We became so fed up with just these problems that we started making our own parts.

We spent a significant amount of effort on the bucks we have used and added stiffeners and supports so that no distortion occurred when we made the moulds.

The moulds were made with the same amount of care and the mouldings produced from our tooling does fit correctly.

None of the bumpers we make suffer from any of the defects you have shown and the brackets we use allows them to bolt up to the car with minimum effort.

The last set of bumpers we made were supplied ready painted and our customer had them bolted to his car in less than an hour.

We had exactly the same issue with duck tails. They never fitted the car and the grilles never fitted the aperture.

We now have our own Ducktail and it fits correctly in all respects.

911R lamp housings never fit SWB car light boxes and the screw holes line up with the holes used to attach the lenses to the lamp housings.

They also don't have to correct curve to suit the inner edge of the SWB Rear Fender.

We have changed the shape of the housing we make so it lines up correctly with a SWB fender and can be trimmed to suit the LWB design.

It will fit into a SWB Light Box and the screw holes line up with the mountings for the lamp housings rather than the lenses.

It really is a matter of attention to detail.

[Uwon]

Hi,
I solved the issue of the spacing with an RS/RSR rubber molding from TRE. It has a nice finish on the exposed end by the rear wheel well and has a groove that fits into the exposed edge on part of the lower edge of the rear quarter panel. It hides allot of issues common with fiberglass bumpers. Also bear in mind that the rear lights when installed complete with lens and gasket will also hide lousy edges, etc.
Also, if your horizontal top edge of the bumper is flimsy particularly below the tail lights, you will probably have to consider fiberglasing in some metal reinforcements underneath and/or thru bolts to the tail light cavity with spacers.
In my build, the portion of the molding from the wheel well to the notch on the bottom edge of the tail light cavity is glued to the rear quarter panel: then cut; then then balance leading to the upright at the rear is glued to the bumper. I found that this method eliminates to re-gluing the molding when I want to remove the fiberglass bumper.
Here are some picks for you.

You can see my build to date on PP
http://forums.pelicanparts.com/porsc...rrera-rst.html
BTW, the license plate is a present from a friend. I live in Ontario, Canada.
Hope this helps
Johan

[obscene]

Johan, thank you so much for the pictures and explanation. I think you're absolutely correct with regards to the rubber seal taking up some of the gap.

[76911S]

Thanks, Mark. The bumper is from a highly regarded source which leads me to believe the whole fiberglass market is a crap shoot. The budget is already blown so maybe it's time to price out steel bumpers...

How long has it been since purchase? I would go back to them with this and request some assistance. Also, I purchased a front bumper that literally just bolted up and looks great. All FG is not created equal.
Not trying to talk you out of steel, but those will cost a lot too.

Mark..

[Norm01]

I'm not so sure you have a big issue here. I'm fitting my rear bumper right now and ran into the same type of problems. It seem your centre panel is not raised enough, I had two problems causing this. The first is the lip at the back and on top of the bumper, make sure it is trimmed to the same height as your original, for my 68 it's about 1/8". The second issue is the side trimming of the lip of the bumperette, there should be none, it should be flat as a bumperette, also look at the radius from the bumperette to the bumper top, there should be no radius, it must be cut square as the corner of your light box. Once these trimmings are done I suspect you should be able to fit it properly. BTW, trim with a grinder and diamond blade, makes fast easy work of it. Hope this helps.