I did a detail on a 2000 35' RV recently and wanted to do a post here in case any of the information might be helpful to others at some point. I also wanted to thank Nick again as I emailed and called him with a couple questions about this detail. Thanks for your help, Nick!
A little bit of history on the "whys" of what I did: I had originally quoted the customer for a wash and all-in-one wax, to address the moderate to severe oxidation on parts of the RV. That was not in their budget, so while a cleaner wax was really what was needed, we decided on a wash and wax, and depending on time I would try to address some areas with #50 cleaner wax. The RV was pretty filthy in many areas (it is used as a fixed residence so has been parked for a while - it had some algea, caked on dirt, etc). When I first inspected it for the quote I saw the bottom was not as oxidized as the top, and the back was really bad. The bottom 2' or so is burgundy base coat/clear coat, and the rest is white gel coat with some vinyl decals.
Once I got setup in the morning I started on the roof. My weapon of choice was a brush with an extension pole. After speaking with one of our local RV shops to make sure it was OK to do with that model, I climbed up on the roof and got to work. I used about 2 ounces of Hyper Wash in 2 gallons of water (intentionally diluted pretty strong because of the grime I was dealing with). I hosed a section down, dipped the brush in the bucket, and scrubbed away. After I got the first layer of grime off, I rinsed it and the brush and hit it again. Troublesome spots got treatment with Wash Plus+ and either a bug sponge or a terry cloth. I used a relatively soft dish brush to get around the AC units, marker lights, etc. The water pressure was pretty poor so everything had to be scrubbed off. With the oxidation I'm not sure if water pressure would have helped much but I did wish I had brought a pressure washer either way. I don't use one when washing vehicles normally but in this case I think it would have helped. Lesson learned. As much as possible I tried to stay along the center ridge of the roof as it was definitely well-supported. When I went near the sides I went slowly and "weight-tested" first. Only once did the roof flex underneath me a little so I just stepped on a different part. I was concerned about it being slippery but it was not too bad. It took 2 hours total to clean the roof.
I continued roughly the same process along the sides. Since I was on the ground now instead of wrangling stuff on the roof, I went to the 2 bucket method. This was definitely worth it. I had to dump the rinse bucket a few times because the rinse water got loaded with dirt and some of the oxidation that was coming off. This RV was around 10 feet tall. I was able to scrub all the way top to bottom with my brush, but then I had to get up on the ladder with my dish brush, Wash Plus+, and terry cloth to scrub better around the top trim, the (rolled-up) awning, windows, marker lights, etc. So I had to use a ladder around every inch of the RV. To do the back and the right side took another 2 hours. The front and left side took another hour and 45 minutes, so 5 hours 45 minutes total for the wash.
Once the RV was clean I was able to see the true condition better. While the back was definitely the worst, the sides were pretty oxidized as well. As much as I wanted to buff the back, it would have made the sides stand out like a sore thumb. I mentioned again to the customer about using an AIO on the whole thing but they wanted to stick with the original plan (understandable). The burgundy was in pretty decent shape. Since I couldn't really do any of the gel coat without making the rest look worse by comparison, but I wanted to give them an idea of what a cleaner wax could do, I did the burgundy on the right side with PRC/D151. I worked it in pretty well on some scuffs but otherwise did a pretty quick buff. It definitely made it look better, but it was subtle enough that it wouldn't drive them nuts if they don't decide to get cleaner wax done on the rest at some point. This took about 45 minutes.
Left with what to do with the gel coat, I decided to try Ultimate Fast Finish. Note: UFF is not recommended by Meguiar's for gel coats at this point (and I would guess will never be recommended for an oxidized gel coat). I didn't want to use any standard wax as I suspected it would be very difficult to get an even finish with the oxidation. It was UFF or a spray wax. UFF worked great. Despite the oxidation, UFF was easy to spread and wiped off easily. I applied it by hand with a foam applicator for the majority of the RV. At one point I decided to give it a try with a black pad on the G100 at speed 3.5. It spread easily that way, but even with the low speed and black pad, I was removing a little bit of the oxidation in an uneven pattern so I went back to hand application. In retrospect, probably part of the reason for the oxidation removal is my tendency to be heavy-handed on the G100 (the majority of the time I used it I'm applying a cleaner wax or compound so it's habit). On the burgundy BC/CC the G100 did just fine and helped speed up the application. I buffed it off with an MF (the included MF is quite nice, btw).
It took about 2 hours 45 minutes to apply UFF to the RV, excluding the top (the customer didn't want it waxed).
A few notes on the products used:
Hyper Wash: I don't have to say much here. It's great stuff, as always.
Wash Plus+: Meguiar's has an oxidation remover scrub for gel coats. If I had been able to get it locally I might have tried it. But once I thought more about it, since I wanted the surface to be as even as possible the oxidation remover might have actually tended to prevent that unless applied just right (unfortunately in this case what was needed was to leave the oxidation as even as possible). The Wash Plus+ had pretty good scrubbing ability. I actually liked it quite a bit, particularly on the windows (it worked well to remove the white streaks and mild water spots on them). Three things about it that I found interesting: 1. It rinsed off way easier than I expected based on how lubricating and sudsy it was. I expected it to be a pain to rinse off but it wasn't at all. 2. I'm not sure the why (probably just because it cleaned that well), but the windows went from not beading at all (after washing with the brush and Hyper Wash) to beading quite well after using Wash Plus+. They weren't even that dirty to begin with. I tried it a couple times to make sure I wasn't just missing something. 3. It worked pretty well to scrub the white off of the window trim/seals. The white seemed to be some minor oxidation on the black window trim. Wash Plus+ did a great job on it. I like it quite a bit and will probably keep some on hand.
Ultimate Fast Finish: I was impressed with how easy this was to apply, even on the bad oxidation. It added some slight gloss. I don't know how much it will actually be able to protect since I was effectively putting it on a porous surface. But I would guess it's better than not anything. I'll try to stop by sometime when it's raining and take a look at how the water acts on it. UFF also goes a long way. While it's hard to be sure, I would estimate I used 1/2 to 2/3 of the bottle on the 35' RV. Not too bad, I think. I see this as being a really good product for a customer who just wants a good wash and wax job cheap.
The customer was happy, I was happy. It was tiring, but the weather was beautiful for it, and there was a sense of satisfaction in having completed it. Perfect? No. Greatly improved? Yes.