CO951

Several of the batwing mounting holes/tabs got ripped off on the bottom of my turbo bumper cover. I've heard they can be repaired. Is this something I can do myself, or do I need to find a shop to get it done right? Because they are covered by the batwing/splitter, looks aren't near as important as strength. On at least two of them I don't have the piece that was broken off, so it would need to be built up or find some piece to replace it. I've seen plenty of bumper repair products, but am not sure exactly what our bumpers are made of and how well these products work, since strength is very important.

H.F.B.

I can recommend TEROSON PU 9225
http://www.loctite.co.uk/loctite-408...=8802621849601
http://www.loctite.co.uk/uke/content...sticRepair.pdf

Two years ago, I damaged my 951 front bumper on one side badly. And some mounting holes got ripped off too. Then I gave the TEROSON PU 9225 a try before simply buying a better user one.
Just do the repair exactly according to the instructions. This stuff does a sort of reweld of the parts to get them durable together. On the web there are many howto videos available.
Unfortunately I have only taken this photo of my at this point nearly repaired bumper. It shows the rough repaired mounting holes with applied filler, just to look how it will fit. After some more sanding and a bit spraying it looked like new.

CO951

Did you use that to reattach the torn off plastic or rebuild the area and place new holes?

That exact product doesn't appear to be available in the USA, but I'm sure there has to be something similar here. Anyone have any experience with any other products?

H.F.B.

Yes. That's the way I did it. First I reattached the torn off plastic. But I utilized a thin sheet metal to support it. Then I rebuild the area and placed/restored the holes. That's the intended purpose.

djantlive

I had some crack and missing tabs on a bumper and it was repaired by a mobile guy easily. It was very strong. He used flexible epoxy that matched the bumper material well

harrisonrick

3M makes a good product specifically for the type of plastic these covers are made from...can come in squeeze tubes at a distributor or a double cylinder with gun.(body shop) There's an adhesion promoter that can glue tears together, and you build it back up.

CO951

Do you know what the product is or what type of plastic our covers are? I thought I saw polyurethane on here in the past, but can't seem to find it to verify.

H.F.B.

Yes it's PU (polyurethane).

Dash01

Do a search and you'll find various posts and questions by me about this. I bought some super duper fixer epoxy stuff at an auto body supply house, but did not use it (yet). As noted by others, 3M and other experts make some superlative products for plastic bumper cover repairs, and I assume all are excellent products.

Note from the above that the part is polyurethane.

I took a composites class for marine and aerospace fabrication, and learned that the proportion of fiber reinforcement is critical: The higher the ratio of fiber reinforcement to plastic (epoxy, polyurethane, polyester, etc.), the better, provided there is enough to fully penetrate the fiber. The fibers encapsulated in the mix are the strength of it, the plastic just holds the fibers in place so they can withstand the stresses.

Curious, I wondered how Gorilla Glue would work, since it is polyurethane, cured by water moisture in the air or sprayed on the work. Being polyurethane, it would be very compatible chemically with your polyurethane bumper cover, i.e., it should bond very well, whereas other adhesives such as epoxy may not necessarily bond to PU as well. Gorilla Glue is some seriously strong stuff, and costs a tiny fraction of the specialty products. Keeping in mind that more fiber = more strength, my choice is to use Gorilla Glue and a lot more chop/mat fiberglass reinforcement.

I had a crack on my front bumper cover from the right side upper corner, extending about 4" diagonally down. I drilled out the end of the crack with a 1/4"' drill, to alleviate stress concentration there. Then I put the GG/fiberglass patch on several months ago, have bent/twisted/sanded/manhandled the bumper cover quite a bit while messing with filler and repaint: The patch is holding well with no signs of failure. Once back on the car and fixed in place with all the fasteners, it should be subject to far less stress and torsion than when working on the bench.

Stay tuned. But at least consider that Gorilla Glue at ~$5 for a small squeeze bottle would probably fix about ten of these bumpers so damaged. The fiberglass reinforcement can be simple drywall fiberglass tape, with several layer laid in different directions. Or just use a small scrap of fiberglass mat.

Dash01

Do a search and you'll find various posts and questions by me about this. I bought some super duper fixer expoxy stuff at an auto body supply house, but did not use it (yet). As noted by others, 3M and other experts make some superlative products for plastic bumper cover repairs, and I assume all are excellent products.

Note from the above that the part is polyurethane.

I took a composites class for marine and aerospace fabrication, and learned that the proportion of fiber reinforcement is critical: The higher the ratio of fiber reinforcement to plastic (epoxy, polyurethane, polyester, etc.), the better, provided there is enough to fully penetrate the fiber. The fibers encapsulated in the mix are the strength of it, the plastic just holds the fibers in place so they can withstand the stresses.

Curious, I wondered how Gorilla Glue would work, since it is polyurethane, cured by water moisture in the air or sprayed on the work. Being polyurethane, it would be very compatible chemically with your polyurethane bumper cover, i.e., it should bond very well, whereas other adhesives such as epoxy may not necessarily bond to PU as well. Gorilla Glue is some seriously strong stuff, and costs a tiny fraction of the specialty products. Keeping in mind that more fiber = more strength, my choice is to use Gorilla Glue and a lot more chop/mat fiberglass reinforcement.

I had a crack on my front bumper cover from the right side upper corner, extending about 4" diagonally down. I drilled out the end of the crack with a 1/4"' drill, to alleviate stress concentration there. Then I put the GG/fiberglass patch on several months ago, have bent/twisted/sanded/manhandled the bumper cover quite a bit while messing with repaint: The patch is holding well with no signs of failure. Once back on the car and fixed in place with all the fasteners, it should be subject to far less stress and torsion than when working on the bench.

Stay tuned. But at least consider that Gorilla Glue at ~$5 for a small squeeze bottle would probably fix about ten of these bumpers so damaged. The fiberglass reinforcement can be simple drywall fiberglass tape, with several layer laid in different directions. Or just use a small scrap of fiberglass mat.

CO951

Great info, thanks. The Gorilla Glue is interesting, but don't know if it would work for the areas I need to build up new mounting tabs.

Dash01

Keep in mind a couple of things:

1. Bonds may be mechanical, chemical, or both. Mechanical bonding may be enhanced by roughening the surface of the work, such as sanding with 80 grit paper, so the glue conforms to the rough shape and grabs onto it. Chemical bonding is when the adhesive is the same chemistry as the work, or compatible with it, so the new and old materials fuse together as one. I expect that polyurethane Gorilla Glue does both, when applied to a polyurethane part like our bumper covers. Epoxy may itself be very strong, and make a good mechanical grip if it gets down into the micro-grooves of roughened surface, but it may not necessarily bond chemically with that surface. So, for your mounting tabs, it may be useful to do a patch with a double layer of fiber reinforced plastic over a core material such as foam. Make it a couple inches wide, to distribute the stresses over a wider area.

2. Often, you may be designing for stiffness rather than strength, per se. If you make a sandwich structure instead of a thinner single-layer structure of the same overall amount of material, the sandwich structure may be 7-8 times as stiff, all else being equal. In other words, instead of one 1/8" layer of fiber reinforced plastic, two layers of 1/16" FRP sandwiched over a core of 1/8" rigid foam may about eight times stiffer.

RC model aircraft hobby shops have a wide body of knowledge and materials you can use, as these guys are constantly crashing their little planes, so know much about efficient production and repair of plastic panels. You want a CLEAN surface to apply the glue to, so wear rubber gloves and carefully clean the surface of the work, lest body oil from your fingers keep the chemical bond from forming.

Crazy Glue (CA) may also be useful in fiber reinforced plastic. I've used it with carbon fiber to make small repairs, as it's thin enough to flow well into the fibers to hold them fixed in place, sets up quickly, and withstands a fair amount of weathering, etc. I fixed a broken ceramic coffee cup handle with Crazy Glue, and it's still strong after years and hundreds of trips through the dishwasher.

Otherwise, if you spend the money, 3M makes a stick-on patch for plastic parts, a sorta BandAid that reportedly works well, according to body shops I talked to. Not cheap. Body shops, BTW, may not be as familiar with polyurethane bumper covers, as PU is less commonly used by manufacturers than it was 30 years ago.

CO951

I found this video that shows basically what I need to do. http://www.evercoat.com/video/us/ Scroll down to "EVERCOAT Universal Adhesive Bumper Tab Repair." The mesh looks like the same stuff I have for drywall tape. Will drywall tape work? I wonder if I did that with the Gorilla Glue if it would give me the strongest results? I'm sure the stuff in the video is very expensive. Would the Gorilla Glue not release from the plastic spreaders?

H.F.B.

It appears to me, this EVERCOAT Universal Adhesive Bumper Tab Repair is pretty much the same as the TEROSON PU 9225, which I have successfully applied.

Tiger03447

Dear Michael: Check out the products at Eastwood.com..They make a bunch of bodywork patch/repair kits and some great paints and epoxies..