Sunday, June 20, 2010

Motorcycle Plastic Repair - Part 2 - Complex Cracks and Ready for Clear Coat

After what seemed like success on the smaller crack I attempted to repair the larger crack.

After applying ample cement and fiberglass, this crack required bracing to maintain the required shape while curing.
Sometimes one must be creative. After trying several brace points, this one was found to be best. This held the repaired cracks together quite well.

(Picture after the large crack repair had completely cured.)

After the cement cured I removed the VX800 label with a razor blade. Previous attempts with chemicals and sandpaper were successful but required a lot more work than a simple razor.

I then again donned a breathing filter/mask and eye protection, and sanded down the existing clear-coat with #180 grit sandpaper. Where the plastic cement squeezed through to the finish side, excess was easily removed with a razor. The cement will not adhere to the finish. Or more appropriately, didn't in my case. These points were sanded smooth. Yes, some of the welded crack repairs can be seen on my experiment, but with more work and sanding they can for the most part be made invisible on the finish side.

At this point I washed the now sanded, finished side well with soapy warm water, rinsed and let dry. Cleanliness is important if you want a good finish. Even the smallest dust particles will leave marks in the finish.

After the piece was dry I wiped it down with a dry cloth in an attempt to remove the dust. This was a mistake as that created a static charge on the plastic piece, making it attract dust particles like moths to a porch light.

After cleaning the dust off as best I could with a damp cloth, the piece was coated twice with Rustoleum Sandable primer. After drying I wet sanded the primer with #1200 grit sandpaper, rinsed and let dry.

I then applied two coats of Rustoleum Gloss Protective Enamel #7762 Sunrise Red. After three days curing time, the red was wet sanded with #1800 sandpaper and wiped down with a damp cloth. It then received a final coat of red paint.

In this experiment, the final desired result was knowledge and experience, not a perfect piece. Regardless, the resultant piece, ready for clear coat turned out quite well, if I do say so myself. With more sanding, time and a few more coats of primer and red, I have no doubt this could result in a mirror finish.

(Please note that the picture does not properly depict the true color of the paint. It is much more red with a somewhat pearl finish in the sunlight than shown here.)

Coming up - Part 3 - Repairing a complete break.


  1. Looks good there Ken. Did you try WD-40 on those decals. It makes the adhesive come off easy after a good wet down most times.

  2. I did try it. I sectioned off the decals and tried four different methods, two on each decal. One one I tried decal remover and sand paper. On the other I tried just a razor and WD-40.

    The sanding simply did not work at all. My arm would have fallen off if I continued that attempt.

    The decal remover was only slightly effective and left a residue.

    WD-40 helped but left a good amount of adhesive on the plastic.

    The best solution I found was just a razor blade. However, I think a simple razor was most effective because the adhesive was fairly dry. These plastic parts have been sitting out in the desert for nearly 7 years, so the dry adhesive was no surprise.

    I did use WD-40 on a paper warning sticker on the rear fender. Took it right off.

  3. Thank you very much for your hard work and sharing of same. I will save this for later, as I have a couple of places that will crack on mine eventually. dlc - aka - 1991 red VX 800