plastic weld how to
 

I wrote this a few years back, and while searching for it in another post and not finding it on twf I am gonna copy paste the whole thread here:

I cut the fairing so the edges of the hole were straight, makes it easy to fit a filler part in there

http://img232.imageshack.us/img232/2726/image151yg9.jpg


I heated this square until it was flexiblethen clamped it to the fairing and waited for it to cool. Once it was cool I heated up the right edge to form the 2nd curve and the corner. Once that was done I marked from the inside of the fairing where to cut

http://img232.imageshack.us/img232/5475/image152lh2.jpg


This is the final filler piece ready to get melted in. I cut it too big by a fe MM on each edge and hand sanded/filed it to fit. it has to fit very tight or the joints will fatigue and crack over time.

http://img232.imageshack.us/img232/28/image153vl7.jpg


First pass with teh plastic welder, came out good, but it looks like shite

http://img253.imageshack.us/img253/1792/image154hb3.jpg


Ok, that looks better, was sanded using my home made 1x3" block sander

http://img253.imageshack.us/img253/6600/image155kl9.jpg

http://img232.imageshack.us/img232/7665/image156ge1.jpg



There are still some divets and low points where the heat distorted the plastic, which requires some bondo. I try to get the plastic as flush first before going to bondo. I also do my best to use as little bondo as I possibly can.

http://img232.imageshack.us/img232/2867/image159we5.jpg


And finally the finished repair, sanded from 60 to 1000 grit paper, the surface feels like an egg shell, and is ready for paint, or in my case vynil

http://img232.imageshack.us/img232/7030/image160an6.jpg

http://img253.imageshack.us/img253/7738/image161ly2.jpg

http://img253.imageshack.us/img253/7407/image162hi0.jpg

Total 'actual' work time is just under 5 hours. I probably put another 5 or 6 into it waiting for the plastic to cool so I could keep going without melting the plastic until it droops or distorts beyond repair.

The finished product. I'm pretty happy about it, there are some minor imperfections, but you really have to look carefully to see them. I was contemplating adding another yellow piece of vynil to the corners just to keep the black from dominating the front. this would turn the black into more of a stripe. I also added the CBR sticker over the headlight, I was trying to make it look like the black corners were a factory design, I should have done the outline of the R in yellow instead of white, but its too late now.

Also take not of the left side mid panel where I fixed it.

http://img183.imageshack.us/img183/1107/image163wn0.jpg

http://img182.imageshack.us/img182/2540/image164ec2.jpg

http://img377.imageshack.us/img377/5844/image166pk9.jpg

you should come fix my upper lol

You should bring your upper down here for me to fix

What kind of prep work do you do before the plastic welding? I've heard that you're supposed to notch the back side into something like a V shape; is that right?

I've got a crack in a fairing that's been there for years and is finally starting to spread a bit, so I'd like to stop it from getting any worse.

Just sanded into the crack a little, not much really. I had tried putting a V indent front and back but that made the plastic too thin and it would actually distort way to easily.

nicely done, was this from the towing incident?

No, thats how I bought the bike. I got it from a dealer for $2500 with the body damage, plus a minor oil leak from the valve cover gasket.

I stopped by the local dealership to buy a new pair of gloves and to look at bikes, was talking to some dude who just traded in his old 900 for a new gsxr750, and the guy told me the whole history of the bike from when he bought it new in 99 until he traded it in, for a little over 2k. He was genuinely sad to see it go. At the time I would have almost definately never bought a 900 being the wheelie king of the 90s and being the original stunta bike. But I went inside, and saw the dealer wheeling it in back, it was in pretty good condition, so I offered them $2500 for it out the door including tax title and tags, which they did on the spot. They did try and talk me into letting them fix the head gasket which they said was leaking oil, new tires, and the body work. I took it as is

I figure it would have cost them another $1k to get it to showroom condition and charged me $2k. Either way it was a good deal for me. I did the bodywork, tires, and changed the valve cover gasket for $350, and have put one or two miles on it since.


Surprisingly enough the majority of the damage from the tow incident was to the other side

this was my first try at plastic welding the year before: