Sealant for fiberglass roof - water intrusion in cabover.

I removed the existing sealant to install eternabond (although it was not silicone)and cleaned the area well, even using the eternabond pre-treatment--to remove the existing sealant, I mostly scraped it off with a plastic scraper. I bought the metal roller to press the tape into position.
I still had a few bird's mouths and wrinkles so had to slit them and retape in places. I did the roof and the rear seams and all the lights.
Eternabond is available on Amazon as are the caulks. I used 4" and 2" and double sided for some of the lights. I bought the materials originally from a roofing supply company and they called it "miracle" rv tape. It has a finished top, there is also a tape that has a paintable top which I used for our awning. But the repair didn't last because the awning just tore elsewhere.
I have not heard of eternacaulk but would like a way to seal the edges. The tape does pick up dirt, but it also cleans reasonably well with a little scrubbing. I would rather have unsightly tape than a leaky RV.
I have used sikaflex and dicor but don't have much insight into the differences. Also used ProFlex but it hardens in the tube easily and has to be used all at once.
Good luck with your repairs! It does seem like your rig is young and shows how any RV can get leaky even with lots of attention.

I also vote for Eternabond. The key are two factors: Prep and application. As stated above, the area needs to be clean, especially if silicone caulk was used. After that, it is application, and it takes proper pressure to activate the microsealant.

The one thing I might add is using EternaCaulk on the edges of the tape. It doesn't provide major protection, but it helps keep the tape looking decent by preventing road dust from adhering to the sides.

New product is sticknbond tape. Flat surface use Dicor self leveling. On vertical surface use Dicor non leveling caulk. You need to scrape all the silicon off and clean surface well. The silicon unfortunately was an amateur attempt to seal leaks which doesn't work very well.

Second vote for eternabond here. Make sure you get a metal or hard plastic roller, though. Rubber won't do the job well enough.

For figuring out where the leak is, I have seen pics of someone who made his own pressure testing setup by using an electric blower, putting it through a piece of plywood and rolling it up in his passenger window. You could even buy a couple of blowers (more power is better in this case) and rig them up for less than the cost of a professional doing it for you once. Then you could reuse that setup each year. Wait ...... now that I think about it, I might make a double blower rig myself.

Jose

tmaxx, I use sickaflex 21 on the sides and anywhere a standing bead is needed. Dicor is good too just make sure you use the non self leveling on areas like window seams side seams and any where a stiffer caulk is needed. then use the self leveling on flat seams like those on the roof around skylights and flanges. the worst thing to use is silicone.It does not last and it leaves a residue that other caulks wont stick to. you need to peel off all the silicone and prep the seams with a solvent like acetone to get rid of the silicone residue; clean the areas well and follow up with a dry rag. DO NOT LEAVE THE SOLVENT ON TO LONG IT WILL REMOVE PAINT! but if your careful you will do no harm. I like to dig back in under the seam a little then apply the new caulking feathering it out so you don't leave pockets for water to stand and freeze in. More than likely your leak is coming from a window or out side seam near the bottom of the cab over. eturnabond works well on flat seams but can be used about anywhere. its not pretty and its pretty much gonna be on there for a long time any where you put it and it works very well but it can be fugly if your not careful applying it. Hope this helps some

What a sad deal. Only seven years old. You should probley have the rig pressurized and checked all over for leaks.Is water puddling on the roof or just not draining? Find the source of the leak. You have been given greaat advice on sealer.

Definately Eternabond Tape......you can get a couple of different widths and colors.....clean the area well, you can cut the tape to the best width and length , and apply.....For visible area use a good Dicor sealent (tube) ...