Fairing Repair Question

[m_stock10506]

My fairing panel got shattered by a deer, three weeks ago. I’m fine. I bought a replacement panel on eBay in pretty good condition but a few blemishes. There’s a crack in the oval cutout that sits over the cylinder head and exhaust header. It looks like it got a little heat because the area where it is cracked is bowed down slightly. Don't know if the material has changed over the years, bike is an R1100RT.

Before I try to repair the crack, I was going to try to get the bowed ends back closer to horizontal. If I apply a little heat to the area will the material soften so it can be pulled back or will it just get brittle? Or is the best approach to just leave it as is?

 

[t6pilot]

Are you planning on painting it? I would suggest a auto body shop, they are familiar with plastic repairs. At the least they could point you in a positive direction for proper repair

 

[m_stock10506]

Yes, I will be painting over it. The eBay part is a different color than the rest of the bike. I got a color match paint and a primer. At this point, with this bike, I'm thinking good enough is okay. If my work is really bad, I could go to a pro painter later.

 

[lkraus]

I'd drill a hole at the end of the crack NOW to spread the stress and keep the crack from growing further. I know ABS is a weldable plastic (see YouTube), but my limited experience has only been with repairing softer plastics like garbage cans (worked great). I don't think it would hurt to try a little heat to soften and reshape the bowed portion. Bring up the temperature gradually and back off if it starts to smoke or burn the paint. Might need to use an actual heat gun, but a hair dryer on high might work. I'd keep the gun moving in circles around the crack to control the heat build up.

 

[henzilla]

I would go the well enough alone route myself. That plastic seems to get even more brittle as the years go by. Have used epoxy like JB weld on backside to reinforce a crack like that or attach a broken mount like the S panel has. Just dealing with backside of damage would keep you playing the color match game on the exterior surface.

Only you and the low to the ground critters can actually see that particular crack...my worry is making an annoyance a costlier annoyance

 

[m_stock10506]

Thanks Steve. I’m going to try and work on the uneven part as minimally as I can to avoid making things worse. Like I said in my OP, the panel has a few issues. There was a crack also at the bottom of that oval where the small piece comes up to connect with the shark fin. JB Weld on the back side of that crack made the area completely secure and solid. Once I get the crack close to flat, I will apply the JB Weld to that area too. All the clips and other parts are removed so it can be sprayed.

 

[23217]

I would use epoxy. Put fiberglass matt in the middle of the epoxy.

 

[lstayner]

I purchased some Plast-aid for cases just like this. I haven't had an opportunity to try it yet but the Youtube videos look like the stuff is just what you are looking for.

https://www.plast-aid.com

Another fix I have seen on this material is super glue and baking soda. That one I have tried on a wood crack and it has some promise.

 

[m_stock10506]

Update! I placed a flat metal flat underneath the cracked area and then placed two spring clamps next to the crack one on each side. The clamps put pressure on the plastic, pushing it down towards the metal flat. I then used a heat gun on low setting and warmed the fairing. After only a short time, the bowed area relaxed and the crack itself closed, partially. I removed the heat and let the fairing cool. The cracked area is nearly flat now. I applied JB Weld to the back of the cracked area with some mesh embedded. The area is flat enough and seems strong. I will sand it and the entire fairing will be painted to match the bike.

 

[Anyname]

I have a vague recollection that BMW labels all their plastic parts with the specific type of plastic. Their intent was to aid recycling, but knowing the specific plastic might help in deciding what approach to use.

 

[BC1100S]

The cracked area is nearly flat now. I applied JB Weld to the back of the cracked area with some mesh embedded. The area is flat enough and seems strong.

Nice! A little ingenuity goes a long way.

 

[crucian]

JB Weld Forever

JB Weld and fiberglass screen! Your approach was flawless. I've used that combo on countless jobs including a hole in a mower deck and the repair is better than the virgin material.