[TomO]

Originally Posted by Christ

Are you using a solder iron to weld? What details of the process can you provide? I have some motorcycle plastics that need to be fixed, and I'd really like to make them look like they're supposed to look before I sell them, from a Ninja 250.

I am using a Weller Soldering Gun:

It's a 140/100 Watt model with the wide, flat tip. I use a zip tie to hold the trigger down to the 140W setting and so my fingers don't get tired.

I lay the tip flat against the two surfaces and heat them up. Once they start to melt, I then push inwards and down at a 45* angle to meld as much material as I can. Then I slide the tip along the surface to the next spot and do the plunge again, creating a "Stack of Dimes" as welders call it. This is all on the backside of the plastic and is the important weld for going deeper into the material and getting a good bond.

On the front side, it's about the same, only I don't go deep into the material. then I go over the whole weld on the front side again slowly dragging the flat part of the tip along the weld to knock down and fill in the "Stack of Dimes". This makes sanding (with 120 grit) a little less time consuming.

Originally Posted by Christ

I've never welded plastic before... Can I just use another scrap piece of the same type of plastic as a filler?

Yes as long as it's the same material you can use it as a sort of "welding rod", just make sure you get all three parts warmed up and melted.

Honestly though, if it's a crack in the fairings and the pieces are all still there and line up easily, you shouldn't need a filler rod. I got away with that on the crack repair on this bumper.

Originally Posted by Christ

I've heard that you can "glue" ABS using acetone... know anything about that? Supposedly, it discombobulates the plastic and allows the two discombobulated sections to stick together as though they had been formed that way. Sounds iffy...

I've heard this as well...I don't have any ABS to try this on at the moment though. I'll have to find some and try it out.

Almost all auto bumper covers are made from TPO, or also called TEO. ABS is not a compatible plastic to use, and I'm not sure what your fairings are made of. Luckily though you can look on the inside of the part and usually find "TPO", "TEO" or any of the other variants of the Olefins on the back. That family can be welded together pretty easily.

Originally Posted by MetroMPG

Bummer about the bumper - did the driver take responsibility? Another teacher or student??

The driver took responsibility, it was just that driver being stupid and backing into me at a line for an ATM, even though she was next in line, the person in front of her was pulling away. She saw the adjacent ATM had just opened up and was going to pull over to that and backed into my front bumper with her Expedition's trailer hitch. I wasn't able to back up and laid on the horn, but it did no good, she didn't even look in her mirrors or behind her and claimed to not know the horn was for her.

The police were called and a report was taking and she plainly stated that she backed into me, which was good. But no claims to insurance were made by either of us. No damage to her trailer hitch, and the hitch actually hit my license plate and only cracked the bumper cover, so no reason for me to file a claim either since I fixed it myself.

So all-in-all I took this as an opportunity to learn a new skill and make something better, which worked out well as I only have $5 into this project. The donor bumper was free from the junkyard, the aero bumper was given to me as a freebie a while ago, and I already had the soldering gun, so I only had to pay to get some more sanding discs.

Oh, and I already have color matched paint sitting around the garage from when I last painted my car as well.