Hey everybody! I recently laid my F4i down and had to do some fairing repair work, so I thought I would create a little “How To Repair Plastics” tutorial. Keep in mind, I am not a professional, so if you use my methods and something doesn’t work, YOU CAN’T BLAME ME! I would simply like to share the process that I used so you foos that busted up yo stuff can get back on the road. I will post the URLs for the pics for all you dial up people, there are several pics.
Okay first of all, I did a substantial amount of damage to the lower right fairing, so it had to be replaced. Instead of going with a new one, I opted to purchase a slightly damaged fairing off of ebay for about $50 shipped, and repair it myself. So here it goes….
The first step was to strip the stock vinyl graphics off the plastic. To do this, I used a heat gun and some adhesive remover (goof off). This part is a pain in the ***. You can figure out the best method of getting the decals off, but keep in mind a heat gun helps immensely!
Here you can see some of the damage that the ebay fairing had. A crack along the top edge and a small hole at the corner:
A transverse crack at the top edge:
And some minor scuff marks:
The important thing here is there are no broken mounting tabs or cracks in load bearing areas. This is good. We can work with this.
We’ll start with the cracks at the upper portion of the fairing. First, sand all the paint around the damaged area (inside and outside) off with a heavy sand paper, such as 80 or 100 grit. You want to use something rough so the plastic filler and epoxy will stick. The scratches that the heavy grit paper leaves will be filled with the filler so don’t worry. I even roughed up the areas further with a dremel tool.
Outside:
Inside:
Outside:
Inside:
Now, this is the stuff I used to fix the cracks. It is a two-part marine epoxy that can be found at Home Depot. The reason I chose this particular epoxy was because of its elasticity and vibration resistance. Once cured, It can stretch up to 30% without tearing.
Now, there are various ABS repair materials that can be found at most automotive paint supply shops. The better ones require a special gun, but work very well. For the little bit of damage I have here, I think the epoxy above will be fine. I also used some fiberglass mat (E glass) to reinforce the epoxy.
Okay, mix up some epoxy on a piece of cardboard or something and spread it on the inside of the crack. Try to force it into the crack as much as possible. After you get a layer of epoxy on there, cut some glass mat and lay it down, pressing it into the epoxy:
Now, you would probably be okay with just this, but for safe measure I put another layer of epoxy over the glass mat:
Here are the same steps with the other crack:
This will have to sit for awhile, so put the fairing down making sure to support it properly to avoid stressing the repair area. With this particular epoxy, I let it sit for several hours (overnight).
Next day:
Okay, momentarily I will jump to the surface scratches because I did all of the body filling in one step. The plastic filler that I used is called Poly-Flex, by Evercoat. This filler is specifically for ABS plastic, and it is very flexible. This can be found at an automotive paint supply store. Remember, traditional body filler (Bondo) is not very flexible, and most likely will not stick to the ABS plastic. Here is the goodness:
As before, rough up the damaged areas good with heavy sandpaper (80 or 100grit):
Mix up some filler with the specified amount of hardener, and using a spreader, spread a thin coat of the filler over the damaged areas:
You have to work quickly with this stuff because is hardens very fast. Give the filler an hour or so to harden before sanding.
Once the filler is hard, you can sand it with a sanding block and 150 – 300 grit sandpaper. If you will be using a high build primer, a heavier sandpaper can be used. Just use your best judgment on whether the primer you are using will be able to fill all the scratches you are making. Don’t get too aggressive, just take your time. Also, if possible, use a block to get a nice, flat surface. Otherwise you could just sand all the filler off leaving the same hole you just filled. If you take too much off, you can always add more filler. Around the edges, I had to basically rebuild the damaged edge. This is the hard part. Here are some pictures after sanding:
Okay, almost done. Once your piece is all sanded and dialed, scuff the rest of the fairing with a scotch bright pad. This will just take the shine off the paint, promoting the primer to stick:
Now you’re ready for primer and paint, BUT FIRST! Clean all your pieces very well with laundry detergent to get any oils or particles off the surface. When the pieces are dry, wipe them down with a tack cloth.
Here are all my body pieces prepped and ready for paint. Note: Don’t ever buy a “custom” painted helmet from anybody because of people like me that fall and repaint the ***.
I hope this little write up gives you the confidence to fix your own plastic. If you have any questions or comments please email me at logansmith23@hotmail.com
Stay tuned for an update on how to paint these pieces. That will be going down this weekend, so if I have time I will try to take some pics of the progress so you can see the fairing finished in all its glory. Good luck! 
-Logan