Besides the window polishing, I’ve also been polishing the many, many plastic lenses covering the various emergency strobes, turn signals, scene, reverse, brake and intersection lights spread all over the truck. Some of these were in okay condition, but many of them were over-tightened resulting in stress cracks and most have fogging from sun damage. A few were evidently replaced more recently as they are still in what I would consider new condition. The headlights are in great shape and don’t require any polishing.
For those lenses that need some cleaning and polishing I’ve developed an effective, though elaborate, procedure that takes them from badly fogged to optically clear. I was originally going to leave much of this work until a later date once I was on the road, but as I pulled many of the light fixtures off the truck during my electrical explorations I noted the aforementioned cracks. Besides trying to prevent further cracking I also also wanted to eliminate as much water ingress as possible.
On a side note I also explored the possibility of simply replacing the lenses that were in the worst condition. All but one of the emergency strobes and scene lights on my truck are made by Whelen. Even used on eBay these lenses command a premium price of $60 and up or are in worse condition that what I have.
To repair the cracks in the lenses I’m using clear Gorilla Glue which dries to a somewhat flexible consistency. I’m hoping this will make the repairs less brittle in addition to sealing them from the elements. The cracks all originate from the mounting screw holes that not only hold the lens to the light head but secure the entire assembly to the body, so even if I only hand-tighten the screws they are still going to be stress points. In some cases, the screw hole mount formed in the plastic had completely broken off.
Above you can see the before and after using the rear turn signal lenses as an example.
Polishing procedure:
- Wash with Simple Green, a detail brush and scotchbrite pad as necessary, rinse.
- Hand wet sand with 1000 grit sandpaper, rinse.
- Hand wet sand with 2000 grit sandpaper, rinse.
- Hand wet sand with 3000 grit sandpaper, rinse.
- Machine buff with yellow (medium) or blue (fine) foam pad and rubbing compound, depending on severity of remaining scratches.
- Hand apply Meguire’s Plast-X plastic polish with microfiber applicator, rinse.
- Hand apply ceramic wax and buff with microfiber towel.
- Spray on clear coat UV protection.
It’s a time consuming process, but not an all-together unpleasant one. I may not still be saying that after I’ve polished all 40 of the lenses on my truck, but I’m extremely pleased with the results thus far.