Fixing an RT fairing

[fpresler]

Hello all:

I have the opportunity to purchase a 1984 R80Rt for a very fair price. It has been in an accident and the points where the fairing frame screws into the fairing are all blown out. Owner has tried everything short of taking it part and taking it to a fiberglass gut to fix. Any thoughts on making it secure again? I'm actually thinking about just putting a rifle fairing on it or making it a naked /7. Thanks.

[shire2000]

I fixed one at home using fiberglass. I ground down the old mounting lugs. Took some steel pipe and threaded it. Cut to appropriate length and welded a small plate to the bottom (about 1" round) and then fiberglassed the whole thing back into the fairing. Once cured, painted the whole inside of the fairing a nice matte black and you can't even tell that they were repaired.

[vanzen]

fairings are pretty easily repaired, although the mounting tabs likely present the most difficult scenario ...

BMW fairings are considered "SMC"

QUOTED FROM "Fiberglass Repair - Composite Repair - Fibre Glast Developments":

"A new composite material is gaining widespread use in the automotive, industrial, and personal watercraft markets that presents unique repair problems. It is called SMC, or Sheet Molded Compound. Recognizing SMC from other types of FRP composites is critical so the proper repair can be performed. Parts made with SMC are produced in compression molds, so they are smooth on both the inside and outside. That is the first clue to look for when identifying them. Next, SMC parts do not have an outer gel coat, but they are usually painted or color molded. When the paint is sanded off, the underlying surface has a marble appearance. Finally, when damaged SMC is sanded, short coarse fibers are exposed and a dryer powdery dust is produced compared to conventional materials. These hints will make SMC identification quite straightforward.

SMC is a polyester-based material, but it cannot be repaired with polyester resin. This is due to the mold release agent that is present throughout the entire SMC part. Unlike conventionally molded parts where release agents are applied to the mold surface, SMC is compounded with them in the resin mix for quicker processing. This means that as the damage is sanded to prepare a good bonding surface, fresh mold release agent is exposed. Polyester resin products are not strong enough to adhere to this surface. SMC SHOULD ONLY BE REPAIRED USING EPOXY-BASED RESINS, FILLERS AND ADHESIVES. When painting, use only catalyzed type paint systems."

[shire2000]

So what you are saying is that my standard fiberglass patching on my 30 year old fairing should not have worked? Guess it is my dumb luck. I am not going to speak ill of it anywhere near it, lest it decide to self destruct.:scratch

[fpresler]

That sounds like a good, permanent fix. Do you have any pics of the project?

[shire2000]

Unfortunately no pics taken at that time. Didn't have a digital camera at that time.
The whole process was a little time consuming, as I took the whole fairing off, which is a royal pain. The two upper mounting tabs/lugs were the ones I replaced. I just kind of eyballed the originals (or what was left of them), measured up the depth of ones on a friends bike and made up the little stubs from some scrap pipe I had laying around. I don't seem to throw out much, you just never know when you might need something.

Running a tap through the pipe to create the threads was the hardest part as the wall of the pipe was not that thick. If I have to do it again, I might use something thicker or maybe get a piece of solid rod, drill it out and then tap it.

Fiberglassing them in was easy enough. First a small amount to stick them in the positions I wanted, and at the proper angle from the fairing. Then just build it up, a bit at a time. Eventually I had a pretty good size lump there that gradually blended out to the surface of the fairing. As the fairing is not real smooth on the inside, slightly rough, I just sanded the surface a bit to take out any rough spots. I then masked off the whole fairing and shot the whole thing with an epoxy primer, lightly sanded and shot the whole thing with a nice matte black. Looks original. Can't even tell it was mended unless you know what to look for. And even then, it is up out of normal sight.

My bike is painted the Lava Red (commonly called Smoke Red) so with the gloss black to the edges, the matte black blended nicely.

The next time I take the fairing off, it will be for a full paint job. I have never done the smoke finish on anything before, but after seeing that beautiful paint job in last months ON, I am willing to give it a try. The worst I can do is waste some expensive paint, and if it works out, I can brag about it.

[Bob_M]

I have never done the smoke finish on anything before, but after seeing that beautiful paint job in last months ON, I am willing to give it a try......

Yea baby, a hot pink smoke RT :dance

[vanzen]

...I fixed one at home using fiberglass ...

wiki:
"Fiberglass, (also called fibreglass and glass fibre), is material made from extremely fine fibers of glass. It is used as a reinforcing agent for many polymer products;
the resulting composite material, properly known as fiber-reinforced polymer (FRP)
or glass-reinforced plastic (GRP)..."

are we to assume that you did not use an epoxy resin / hardener ... polyester, perhaps ?

So what you are saying is that my standard fiberglass patching on my 30 year old fairing should not have worked? Guess it is my dumb luck. I am not going to speak ill of it anywhere near it, lest it decide to self destruct.:scratch

:dunno I hope it lasts forever, shire2000.

[shire2000]

Was cleaning up the garage last night, getting ready for yet another project. Have to make room for 2 1970 Triumphs I am going to bring home next week. On a bottom shelf I found the cans of resin and hardener and a small box of the glass mat (now powder) that I used. Low and behold it is the epoxy type. Have had it for quite a few years. Originally bought it to fix an old Shoei fairing for my wife's bike. It probably has a shelf life, but thinking back, it has to be at least 20 years old now. Last time I used it was about 5 years ago, when I fixed my RT fairing. Probably should dispose of it as it is getting very old. Didn't crack open the cans, but when shaking did feel liquid movement inside.

So, I guess I lucked out using the right stuff. I am no body man, more of a seat of the pants guy who uses what he has at hand. If that does not work, then I figure I wasn't meant to fix it. If I haven't totally ruined it, I will then take it to someone that actually knows how to fix what I broke.

[vanzen]

... It probably has a shelf life ...

yes it does, and it ain't 20 years, guaranteed !
Shelf-life depends upon storage conditions and brand.
Dark, cool, constant temperature and well sealed containers are needed for maximum life span.
The USUAL life expectancy is ABOUT 2 years.

So, I guess I lucked out using the right stuff. I am no body man, more of a seat of the pants guy who uses what he has at hand. If that does not work, then I figure I wasn't meant to fix it. If I haven't totally ruined it, I will then take it to someone that actually knows how to fix what I broke.

You are luckier than I –
repairs failed before I "figured it out"

trial & error is a good teacher
don't be afraid to fail if learning is the result!
(or, at least, THAT will be my excuse)

[mymindsok]

I have successfully repaired BMW fenders and so forth by using SIG Aircraft Epoxy, glass tape and microbaloons.

It aint rocket science but the repairs tend to be strong and permanant. In fact, the repairs are stronger than the surrounding material!

I probably wouldnt bother repairing a heavily damaged fairing. Not if swapping to a repro "S" fairing would suffice anyway. Repairing BMW fairing so that they look good is a PIA!