Fairing: beginning crack

[Bjorn]

Hi guys,

 

I was trying to solve some resonating issues of my front fairing, when i discovered a minor crack. To the eye its not even all the way through (yet....). Can only be seen from the exterior side. see the pictures below.

 

So before it cracks completely, do any of you have any experience/tips to repair it?

 

maybe glue a strip of aluminum or similar plastic (abs or polyester?) to the backside?

 

[Craig]

Best bet is to repair it from the rear.  Sand down about 2mm of fiberglass for 2-3cm each side of the crack.  Then build it back up with heavy boat cloth and epoxy resin.  For a perfect repair do the same thin on the painted side, only go down a mm and use 2-3oz cloth. then repaint.

[helicopterjim R.I.P.]

Unfortunately a proper repair would first involve stop drilling the crack with a 3/32 drill just at the tip of the crack - otherwise it may just keep on going. Then buy a plastic weld kit and if you have a dremel then route out a slight channel along the crack - both sides are best - and fill the crack with plastic weld. Then you can sand and paint. Plastic weld usually ends up being stronger than the original plastic so you may find it cracks somewhere else if you can't find where the stress came from causing the first crack.

 

If you don't want to take the time to fix it completely now then I strongly suggest you at least stop drill the crack or it will get bigger. You can maybe fill the drill hole and cover with a green pen for temporary relief.

 

It will mean shooting your Eagle ...

[docc]

That is in an unfortunately very visible location. All of the plastic on the early Sports cracked to pieces. I used both the fiberglass method and, on flat surfaces, blank circuit board epoxied and clamped.

[helicopterjim R.I.P.]

Just curious as to why there are suggestions of using fiberglass on a plastic fairing? Perhaps I am mistaken about the composition of the fairing. It looks like plastic. If it is not plastic then please disregard my suggestions.

[docc]

"plastic" could mean a lot of things. I'm not sure what Bjorn's fairing is actually made of. I think my early side covers (pictured) are some sort of (brittle) ABS, but not sure. When they, and the starter cover, and the front fender, began to come from together, my dealer replaced most of it under warranty but made me promise not to install the new pieces. They look lovely in their little bags.

 

So, I systematically tried to reinforce all the attachment points to varying degrees of success. They all still show cracks in the paint on the outside. I'm not sure at all that those methods would reinforce Bjorn's fairing effectively. No way they would weld the cracked paint.

 

Truly, I am totally unsure if my side covers are a terpolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene.

[Craig]

Just curious as to why there are suggestions of using fiberglass on a plastic fairing? Perhaps I am mistaken about the composition of the fairing. It looks like plastic. If it is not plastic then please disregard my suggestions.

 

To give additional strength over what was originally there.  The plastic welding techniques only bandaid the problem.  

[Bjorn]

I dont have the fairing with me (at my parents house) but usually every injectionmoulded parts has a production clock. Here the material and date is specified. Anyone in the occasion to check this? Because from what i heard you need different methods for repairing ABS.

 

Drilling the crack also came to mind. Please note that the crack is not even all the way through the material (yet). I want to fix it, dont care if it requires painting or anything.

[Craig]

 I want to fix it, dont care if it requires painting or anything.

 

Have you priced a new or used fairing?

[Bjorn]

No i have not. Im guessing expensive....

 

@ jim, is your tip of drilling and repairing For abs or fiberglass panels? Because the terms composite and plastic are both used.

 

Composite= fiber reinforced resin?

Plastic= abs, polyester?

[docc]

The Stucchi faring is definitely a composite (fiberglass) but the later fairings (like Bjorn's and the Givi) appear to be a thermomolded or injection molded plastic without reinforcing material.

 

The brittleness and hardness is what led me to believe it is a styrene derivative. The inside of the early Sport cover reads "Acerbis ABS."

 

Perhaps someone can get a look inside their later fairing . . .  chamberlin?

[helicopterjim R.I.P.]

@ jim, is your tip of drilling and repairing For abs or fiberglass panels? Because the terms composite and plastic are both used.

 

Composite= fiber reinforced resin?

Plastic= abs, polyester?

 

The stop drilling is for plastic .... 

[docc]

No matter the repair, or even with replacement, some attention to the mounting to reduce any stress would be a good idea.

[chamberlin]

The Stucchi faring is definitely a composite (fiberglass) but the later fairings (like Bjorn's and the Givi) appear to be a thermomolded or injection molded plastic without reinforcing material.

 

The brittleness and hardness is what led me to believe it is a styrene derivative. The inside of the early Sport cover reads "Acerbis ABS."

 

Perhaps someone can get a look inside their later fairing . . .  chamberlin?

 

Docc, the only fairing I have is the Guzzi 'farbon ciber' piece... but I would guess that the plastic fairings are Acerbis ABS as you've seen on some of your other parts...

[Bjorn]

I brought the fairing to a local car repair and paint shop. They are going to weld the crack, for €40 im not going to mess around with plastic. Curious how it turns out.