By Russ and Tiña De Maris
When RVtravel.com ran a video that espoused the idea of cleaning RV exteriors with water and liquid dish soap, it didn’t take long for a reader to respond. We were well chastised for the suggestion. “Dish soap is known to soften automotive paint,” came the comment. “Never ever, ever use it on a painted surface.”
To these writers, who’ve been using Dawn in a bucket on their trucks and cars for years, it was a “new wrinkle.” But you learn something new every day, so we set out to find out the facts behind the stories. And it’s hard to pin down a truly authoritative “horse’s mouth” on the subject while there are, admittedly, a lot of other horse’s parts ready to spout off on the matter.
The consensus of opinion from what we’d consider the professional sources seems to boil down to this, as lifted from autos.com: “Dish washing detergent, for the most part, is safe for car finishes. Nothing in dish washing detergent will actually harm your vehicle’s finish, but there are some differences between dish washing detergent and soap that is made specifically for vehicles. One of the differences is that some of the ingredients in dish washing detergent will also effectively strip the waxes and polishes you may have applied in the past off of your vehicle’s paint.”
Will you “hurt the paint”? Doesn’t sound like it. Will you make yourself more work? Pretty likely. If you want a shiny surface, you’ll be back to rewaxing after you wash your rig with liquid dish soap.
But hang on — How many of us have RVs with a finish job like on our toad cars? Not too many. In fact, the swing in industry is to fiberglass with gel coat. What about using liquid dish soap? Here again, the consensus is similar: It won’t actually harm the rig itself, but dish soap will wipe out any wax, leaving you with a need to rewax to get that old shinola back.
If you have a fiberglass-sided rig that’s been seriously neglected, a bit of bleach and dish soap in your water bucket may actually clean the nastiness off the rig. And then you’ll have an opportunity to build up your biceps doing the Mr. Miyagi (“Wax on, wax off. Wax on, wax off” — from “The Karate Kid”).
In any event, if you want to preserve the wax finish, spend a couple extra bucks and pick up soap designed for auto or fiberglass washing.