Step 1: Start by Washing Your RV, Make Sure to Include the Roof, and Rinse Well. Step 2

Step 1: Start by washing your RV, make sure to include the roof, and rinse well.
Step 2: Remove any and all stains, soiling, oxidation, and chalkiness from the surface. Dip a white 3M scrubby into water and then liberally sprinkle Bar Keeper’s Friend (BKF) on it. Scrub the surface of the trailer, rinsing the scrubby and re-applying the BKF often. Do small areas at a time, rinsing well with water and a sponge as you go (Rinsing well is important to remove all BKF residue. I used a "flow-thru" brush attached to a hose to rinse the BKF residue thoroughly).
Step 3: Next you want to make sure that there is absolutely no remaining wax on the RV, since any residual wax can cause the Red Max to peel and flake. Mix up a bucket of TSP - Trisodium Phosphate (1/2 cup) in water (2 gal), and use it to wash the entire RV again. You can use it with a carwash brush, a sponge, a pressure washer…anything you would normally use to wash your RV. Rinse well as you go, then rinse again and let it dry completely (again, rinsing well is important to remove all TSP residue). You should now be left with a clean and smooth (although dull) wax-free surface. Congrats, the hard part is done!
Step 4: Now comes the easy part. Shake the ZEP Floor Finish well, and pour some into a shallow container (a pie pan works well). Fold a microfiber rag to about hand-sized, dip it into the ZEP (trust me, use gloves!), and squeeze out the excess. How much/how wet? You want it more than damp, but less than dripping. Now simply wipe down the surface of the RV with the wet microfiber rag. Don’t try to apply a heavy coat or try to “rub it in”; just wet the surface (imagine wiping off a layer of dust with a damp rag). It really doesn’t matter whether you wipe horizontally, vertically, or in circles, and don’t worry about overlaps; ZEP is very thin/watery and you are just trying to “moisten” the surface. Work your way all the way around the RV. The thin coat of ZEP will dry very quickly; long before you’ve gone all the way around it will be dry and you can immediately start on the next coat.
That first coat will likely look really bad; streaky, blotchy, shiny in some places, dull in others…don’t panic. Each additional coat will start to even it out and build up a deep layer of shine. By coat 3, you will be grinning ear to ear. And coat 4 (or 5?) will be the icing on the cake. Not only will your RV shine like it hasn’t shined in years, it will be a deeper color as well*. Even old, faded graphics will have a new lease on life! All for less than $30 total!
*Note: This procedure will slightly change/darken the color/shade of your RV.
Things (I learned) to keep in mind:
-Don’t use new colored microfiber rags until they have been laundered, as the color may bleed.
-Don’t try to “over-apply”, or try for a heavy coat, or you will get runs. The thinner, the better. Remember, you’re just trying to “moisten” the surface with each thin coat, nothing more. If you are getting a lot of runs, you’re applying it too heavily.
-Be careful around window frames, locks, latches, etc., as the ZEP is very watery and will have a tendency to gather and cause runs. ZEP dries fast, so keep an eye out for any runs and give them a quick wipe before they start to “set up”.
-Some older, deteriorated graphics may “bleed” color onto the rag and surrounding areas. If you notice any bleeding during the BKF or TSP stage (steps 2 and 3), then give a quick wipe of ZEP across the graphics prior to step 4, which will seal them up. Then go ahead and apply the ZEP to the entire RV (including the now sealed graphics) as per step 4 of the tutorial.
-After each coat, go around and open/operate all hatches, locks, catches, etc. The RMP acrylic coating can sort of “glue” them closed.
Maintaining the ZEP finish:
Now that your RV looks like it has a new, clear coated paint job, you’ll want to maintain that new finish as long as possible, right? Well, good news. With ZEP, that’s easy to do as well.
Most commonly used car wash soaps and mild detergents will not harm the ZEP finish, so you can wash your RV as you always have. In fact, you’ll probably find that it comes clean much easier than before, as dirt, bugs, and debris seems to “float” right off quite easily. You do want to avoid anything with Ammonia in it, such as some window cleaners, since ammonia will remove the ZEP (think “floor stripper”). The tire cleaner spray at coin-op carwashes has also been shown to remove ZEP. Minor scratches or blemishes in the ZEP finish can be touched up easily with a quick coat or two of ZEP. Do not apply wax, as wax will interfere with any “touch-up” coats of ZEP later on down the road, causing them to peel or flake.
And after 6 months to a year, if the finish starts to lose it’s shine, just give the RV a good wash job, let dry completely, and then give the RV a quick touch-up coat or two of ZEP, wiping it on just as you did originally.
Disclaimer: This procedure worked wonders on my weathered, oxidized RV, using the products and steps listed above, and I have no regrets. Hundreds, if not thousands, of others have also used RMP with similar results. A very few reports have surfaced claiming "yellowing" or "peeling", but most, if not all, of those have been attributed to improper surface prep. However, these products are admittedly not designed or marketed for use on the exterior of RVs, and I make no warranty regarding their use or the long-term effects on your RV. Use at your own risk.
A few final notes:
Some people have voiced concerns about the chemicals used in the prep stages. Bar Keeper’s Friend (BKF) is similar to scouring powder, but much less abrasive. In fact, it is made for cleaning and polishing fiberglass. Used with the fine white 3M scouring pads, it is excellent for removing stains, oxidation, and chalkiness from fiberglass gelcoat without scratching.
Trisodium Phosphate (TSP) is indeed a very strong cleaner. While it works very well to remove wax from the RV, it can burn if mixed too strong or left on your skin too long. If you are not comfortable with the TSP, some have reported good luck using Dawn dish soap to remove the wax.
Ultimately, neither of these products (BKF, TSP) are required. What is required is to remove all stains, soiling, oxidation, chalkiness, and wax from the surface of your RV prior to applying Red Max Pro, and to make sure that it is rinsed well to remove any residue of what you DO use. Whatever methods you are comfortable with are fine, as long as they accomplish that.