Monday, September 26, 2022


Ask Dave: How can I restore my RV’s dull fiberglass end cap?

Dear Dave,
I have a 2015 Excel and the end cap is starting to dull. What is the best product to restore shine? I hand wax the unit twice a year with Turtle Wax. —Kenneth

Dear Kenneth,
Back caps can be either a molded fiberglass cap or flat layered design like the sidewall. The flat design has an outer layer of filon typically used. Looking at models for the 2015 Excel 5th wheels on RV Trader, I assume your end cap is a hard fiberglass that is either made with layered sheets of fiberglass with resin, or shot into the mold with what is called a “chop” gun. The outer-most layer is a gelcoat, which is the clear shiny material. The thicker the gelcoat, the more shine.

Here is a typical flat designed sidewall with Filon.

This is a fiberglass back cap like yours, just probably a little older.

What causes the dull end cap or front cap

The fading or dull look is the gelcoat exposed to UV degradation from the sun and typically is much worse on the front cap. There are several products that I have used depending on the severity of the fading.

I would start by cleaning the cap with a mild detergent such as Dawn Dish Soap (blue) and water and letting it dry. Then apply 303 Protectant generously over the entire cap. I have used this in the past and it helps clear up the gelcoat if it has not gone too far.

If this does not help, you will need to apply a little elbow grease and buff the cap with either a light polishing compound, or I have used Bar Keepers Friend in the liquid version, as it has a little “grit” to it. Use a 3M foam pad on a buffer and go over the entire cap. Then try the 303 Protectant, or we have used ProtectAll All-Surface Cleaner.

If you have decals or a logo that has faded, you can try these products. However, if it is cracked and peeled, you will need to remove and replace.

As for wax, most recommend Meguiar’s Wax with Carnauba as it has UV protection. I don’t think Turtle Wax does.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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5 months ago

I did my entire coach with Meguires 67 one step. It did an amazing job.It was a lot of work though even with an industrial polisher. I then coated the entire coach with Rejex. This is amazing stuff. once it’s applied the ability for dirt and bugs to stick is reduced. the coach stays cleaner longer. when you’re done the thing looks new. Expect to repeat the process once a year.

Jeff Arthur
5 months ago

3m fiberglass & gel coat restore is the best I’ve found $$$

Jesse Crouse
5 months ago

I am about ready to try Chemical Guys products. Many people speak highly of them. Our coach is a 06 Tiffin Phaeton 40QSH. Last year I removed the 3M bug shield on the front cap. What a PIA to do. Will test a # of products. Good Luck with restoring your back cap.

Capt. Jim
5 months ago
Reply to  Jesse Crouse

Big fan of Chemical Guys products. You can call/text them for advice and recommendations.

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