Long term Zep usage

I have used Red Max Pro for over 3 years now with no adverse issues. I have heard that Zep is the same thing but don't have personal knowledge. Assuming that it is the same thing; prep is the key. The better you prepare the surface the better the result. I suspect that those who have problems skimped on the prep.
After two years I put two more coats on the front cap, no stripping required and it turned out great. One thing I learned the hard way was do not put wax over Red Max. I inadvertently used a wash and wax product when I thought it was wash only. The wax, in a short time, looked very bad. I removed it using 0000 steel wool and the RMP shone thru again.
When applying use multiple very thin coats. The first coat will look very bad, the 2nd not bad and the 3rd will look great. In wear areas such as the front 4 coats is probably best.

Read the thread over on the Fiberglass Trailers forum. It is about the forerunner of Zep, Red Max Pro. The thread started on 07-24-2010 and is still running today. All 629 posts on the topic. And they still are recommending the current Zep product. Zep was the maker of Lowe's Red Max Pro, but Lowes quit making. So now you need to find the Zep product.

I've had RMP on our 96 Southwind for about 3 years. The RMP is still shining and looking good. However, the Southwind is tan/cream in color so I wouldn't notice any yellowing.
I'll continue to use ZEP/RMP.

ZEP/Red Max Pro Application Process
As said by fpresto, the prep is the important thing for a good job.

my boat was badly oxidized when I bought it every spring I tried something new,it is red/maroon.this year I used the zep with proper prep,first time the finish did'd fade by this time of summer,next year the whole boat.maybe mh down in az I have lots of time there ken

Thank you for the info! Will go ck out that thread.