Tech Tips

How to Fabricate & Install a Molded Taillight

Written by  August 31, 2006

For a truly unique, custom effect, tail light molding has been getting more and more popular with the “high end” customizing crowd. In the early days of “frenching,” a true “mold” job was difficult to achieve. Today, products are readily available at most bike shops and auto body suppliers.

The process necessary for achieving professional results tends to require a fairly high skill level, so if you don’t have much fabrication and/or body working experience, this is one project best left to the pros. That’s why I turned to the expertise of Chris Cofield of CC Custom Graphics. I have been around Chris’s work for quite some time and everything he works on is a unique, artistic design.

Chris and I discussed this process a couple of months ago and I felt that step-by-step instructions would be a great way to introduce this process, show you what is involved, and demonstrate how much prepping actually goes into a project of this magnitude.

To demonstrate this process we’re using a custom Fat Boy rear fender. This bike was brought to Bear’s Highway Classics in Avondale, Missouri for service and repairs.

Step 1) This is what it looked like initially. Not sure if the customer backed into something or if stress caused this. Any time you’re dealing with two dissimilar materials, normal expansion and contraction play a huge role in whether or not it will survive for any duration. Note the Fay Boy logo design hand painted on there. Someone did a fairly nice job on this, including splitting the fender and widening it for the 200 tire.

Step 2) Removing the fender, the first thing we did and busting out the old lens. (b) The next thing was to measure the opening for the new lens. The lens material comes in a kit from Hi Tech Lighting. Radar had no problem finding exactly what I specified. I decided that the size of the lens wasn’t big enough to allow for adequate bonding surface, so we’ll have to cut the opening a little bigger. This will also allow for a little bigger light as well.

Step 3) Once I decide the lens dimensions, I marked and cut the red Plexiglas lens material.

Step 4-5) The biggest problem I see with these is that most guys cut the plastic the same dimensions as the fender opening. Then all they can rely on is the epoxy or fiberglass they use to hold the lens in place. You need more of a bonding surface than that. What we do is use a table router to cut a lap joint 5/16” wide and 3/16” deep. (We tested our measurements on a piece of scrap wood before we cut the lens).

Step 6-7) This is what it should look like.

Step 8-9) All edges are sanded smooth and the Prism plastic material is cut to the same size as the lens.

Step 10-11) The lens and prism are glued together per the instructions in the lens kit.

Step 12-13) Now we start cleaning off the old bodywork.

Step 14-16) I cut my new opening based on the size of my new lens. Always drill holes in the corners prior to cutting sheet metal or you’ll end up with stress cracks.

Step 17-19) We use a heat gun to form the lens to closely match the fender’s radius. Be careful not to concentrate too much heat in one place. Heat it evenly until it becomes pliable. The corners will need to be ground off so it will fit the opening better.

Step 20-21) Here it is dry fitted. Note that there is approximately 1/16” of the lens elevated above the fender. This is what you want so it can be shaped later.

Step 22-25) Once it fits properly, all bonding surfaces get a thorough cleaning with fast dry pre-cleaner. We use a high quality body panel adhesive epoxy to bond the lens to the fender. All gaps and voids are filled. Then it’s held in place for 24 hours. Once cured, we add fiberglass cloth strips and resin around the perimeter of the lens for added rigidity.

Step 26-28) Now the bodywork starts. First we mask off the lens and the bare metal gets cleaned, epoxy primed and baked for 12 hours. Then the surface is prepped for short strand fiberglass and finally plastic body filler. When sanding the lens the final step should not be any coarser than 600 grit. After the bodywork is complete it gets three coats of catalyzed primer, and feathered around the edge of the lens. Now it gets final wet sand and we’re ready for the design.

Step 29) The customer decided he would rather have the Harley logo instead of the former Fat Boy design. So I was able to closely duplicate the design on the computer.

Step 30-36) It was cut out on a mask and applied to the lens. Then we spot primed around the design and wet sanded it to feather it in with the rest of the fender. Then the mask was reapplied and the letters removed so only the background is the negative (lit) portion. We also masked the whole design on the back side. Now we’re ready for paint.

Step 37-40) We applied 3 wet coats of House of Kolor Orion Silver.
Then the masking was removed and 4 coats of clear were applied.

Step 41, 42) The bottom was undercoated and then mask removed. We couldn’t help but get a droplight to check out the results!

Step 43-45) Then it’s color sanded and polished.

After all of the time and prep work involved in a project of this magnitude I would give this 8 on our tough-o-meter scale, it requires a lot of body work knowledge and patience and the ability to paint the final piece when this procedure has been completed. So if this is something that you would rather farm out please call or e-mail Chris at the information below. This is definitely the ultimate in a custom tail light and he can handle this with ease.

For more information on this conversion please contact Chris at CC Custom Graphics: 816-916-4995 or This email address is being protected from spambots. You need JavaScript enabled to view it.

B-safe out there!

Dave Miller