R1100RT fairing repair question

[Miguel!]

I removed the fairing from my R1100RT yesterday to replace the battery and complete a few other projects that required the fairing be removed. I had some time so washed down the inside of the fairing and inspected them for potential damage. I found a couple small cracks and a support member that is supposed to be glued to the back of the fairing that had broken free and not attached. I want to fix it before reinstalling. I think the fairing material is ABS. Is that correct? If so, can I use ABS cement to do the repairs? If not ABS, any suggestions on an adhesive and surface prep? 

 

The repairs would not be visible on the outside surface of the fairing. 

 

Comments and advice welcome. 

 

Thanks. Miguel

[nrp]

No direct  experience w the fairing repairs but they are definitely not ABS.  I'd suggest epoxy and fiberglass cloth on the inside.  After wiping with laquer thinner, sand for a fresh surface to improve adhesion, and if possible feather out any crack reinforcements.

[dirtrider]

9 hours ago, Miguel! said:

I removed the fairing from my R1100RT yesterday to replace the battery and complete a few other projects that required the fairing be removed. I had some time so washed down the inside of the fairing and inspected them for potential damage. I found a couple small cracks and a support member that is supposed to be glued to the back of the fairing that had broken free and not attached. I want to fix it before reinstalling. I think the fairing material is ABS. Is that correct? If so, can I use ABS cement to do the repairs? If not ABS, any suggestions on an adhesive and surface prep? 

 

The repairs would not be visible on the outside surface of the fairing. 

 

Comments and advice welcome. 

 

Thanks. Miguel

Afternoon  Miguel

 

They might be as number of motorcycle body panels are made from some type of ABS composite. It might even be a combination like  PC + ABS.

 

On most vehicle composite body panels there is usually a molded in identifier on the back side the panel (identifier is used for both repair info & for proper disposal identification)  . The problem is in deciphering the numbers & letters in that identifier. 

 

You might look on the body panels to find the molded  in material identifier, then Google that info to see if it allows you to identify your panel material. (hopefully it isn't a German exclusive identifier) 

 

Once you identify the material (or material combination) you can then find the proper repair procedure for it. 

 

 

[duckbubbles]

 A couple of years ago I used some 3M Emblem glue to re-attach an inner fairing attach panel on my R11S.  It's still there like it was from the factory.

 

Frank

[Miguel!]

Thanks all. I don't plan on riding today so thought I'd do an experiment with some ABS glue and a surface-insensitive epoxy that Ms Miguel and I have used on LOTS of projects with different materials (stone, glass, plastic, rubber, ceramic, metal, ...) with great success to see how they hold up. I'll clean a small area on the back of the fairing with lacquer tanner and put a dab of each adhesive on and let them cure for a few hours. Then I'll go back and test their durability by trying to scape them off. I'll let you know how it turns out.

 

DR: Thanks for the tips on the material markings. I'll look for those, do a bit of research and report back.

 

Duckbubble: Emblem glue is a interesting adhesive choice. I'll keep it in mind. I don't have any to try out.

[Michaelr11]

I’ve made several fairing repairs, some of these were very involved.  JB Weld makes a plastic epoxy, two parts in side by side syringe containers. If reattaching parts, that’s enough. If filling in cracks or missing areas, add some mesh or fiberglass cloth. 

[Miguel!]

I fixed the fairing today. My finger is pointing to the two parts that should be connected but weren't and required repairing. The two parts should be in contact and "welded" to each other: 

 

Here's another joint, shot from the top, to show what it should look like:

 

I used an epoxy that I've used for lots of things including plastics and it has never failed me. It's pricey but it works, $20 for 0.7 oz. Its Loctite 401 Surface Insensitive Epoxy. Its sets in less than 60 seconds. It worked and is holding fast. If it ever fails, I'll post about that in this thread in the future. 

 

Michael11:  thanks for the JB Weld suggestion.Its also an excellent product that I've used over the years but I didn't have any on-hand. 

 

DR: Here's the manufacturing badge on the back of the fairing. I didn't have time today to research all the codes on the back to see if I could determine the specific materials the fairing was made from. 

 

Best

Miguel

[catskill]

The fairing is a mixture of Polybutylene Terephthalate and Polycarbonate. It is often marked as PC/PBT. Sometimes the PBT will also be glass reinforced. I don't think this fairing has any glass or carbon fibers added. But, probably your best bet would be fiberglass mat with epoxy. Clean the area an rough it up before applying.

 

The PC/PBT has good chemical resistance, but has a lower melt point then I would like. If you leave the fairing panels off for too long, the shape will change, and the screws are hard to put back in. I would have used PET instead if I was the chemist.

[Miguel!]

Thanks Catskill. I appreciate the chemistry lesson and PC/PBT is what is shown on the back of my R1100RT fairing shown above. 

Miguel

[Dave P]

If it's a spot that is not really visible (like down under the cylinder), I would probably back the break with a 1/8 or thicker piece of plastic, heat it up to bend it to shape and secure it with 4 pop rivets. A bent piece of plastic (abs probably) with holes drilled and Plexus or even JB Weld would probably work, but rivets will never let go. Holes in the backer let the epoxy mush through and help lock it in place

[Miguel!]

Good advice Dave P. Thanks! Miguel

[Dave P]

Guess I meant above the cylinder 🙃.

 

I repaired a 2" crack on my wife's 2003 Beetles bumper a few years ago with a small piece of bent plastic with a bunch of holes drilled, rough up the glue surfaces really well, glued with Plexus and clamp for 8 hours. That crack NEVER moved! Dave

[Miguel!]

I didn’t know plexus made epoxy. I was unable to find it with a quick look. 

[BrianM]

Plexus adhesives may be a different company than plexus plastic polish.

 

https://itwperformancepolymers.com/products/plexus/

[Dave P]

We use the Plexus at work. Never knew there were so many variations. I'll snap a pic of the tube and post tomorrow. D

[Miguel!]

I think they are two different companies based on a quick look. one makes epoxies, the  other plastic cleaners.

 

Miguel 

[Dave P]

Here's the stuff I used

[Selden]

I repaired exactly the same break four years ago, putting fiberglass cloth on both sides of the break. It was still intact when I sold the bike in June.