Fantastic Fans - Best Caulk to Use

[anypaws@gate.net]

I have bought a used grooming van that has 3 Fantastic Fans installed. Two of the 3 fans have leaks around them. We removed the old caulking and recaulked with a self leveling caulk that we bought from the RV supply store (sorry, can't remember the name), but there are still some small leaks when it rains. The new caulking can actually be pulled right off. The conversion company used GE Clear Silicone when they installed the fans. What would be the best caulking to use around these Fantastic Vans to get a final seal over these leaks?

[boardster]

I have bought a used grooming van that has 3 Fantastic Fans installed. Two of the 3 fans have leaks around them. We removed the old caulking and recaulked with a self leveling caulk that we bought from the RV supply store (sorry, can't remember the name), but there are still some small leaks when it rains. The new caulking can actually be pulled right off. The conversion company used GE Clear Silicone when they installed the fans. What would be the best caulking to use around these Fantastic Vans to get a final seal over these leaks?

Pull 'em off, run a course or two of butyl tape, and re-install.

[Altered Sprinter]

I have bought a used grooming van that has 3 Fantastic Fans installed. Two of the 3 fans have leaks around them. We removed the old caulking and recaulked with a self leveling caulk that we bought from the RV supply store (sorry, can't remember the name), but there are still some small leaks when it rains. The new caulking can actually be pulled right off. The conversion company used GE Clear Silicone when they installed the fans. What would be the best caulking to use around these Fantastic Vans to get a final seal over these leaks?
Look at this link bought to you by search Google and linked to advanced search tool on the forum this is a brilliant tool to learn how to use.Sticking Fantastic Vent Fan Cover - Sprinter-Forum (http://sprinter-source.com/forum/showthread.php?t=732&highlight=fantastic+vents) There are eight threads to chose from, Suggest you remove the entire vent remove silance with plastic scrapper and then use a product called HG sticker remover or gunk off you have so many at your end dammed if I know which one :idunno: cleans of stickers glue, rubber-based glue, silicone, tar and smear marks etc.

Once pre-preped use a clean cloth with wax prep off remover wait 20 minutes for solvents to dissipate use a tac-off pad ,then apply this product SIKAFLEX-291 not 221..291 is a flexible adhesive with high bonding quality; it's 100% waterproof and expands and contracts between both surfaces, very forgiving under any temperature , the product will and is 100% compatible to taking to [A] a plastic type base and [b] Mercedes-Sprinters OEM paint work it will not melt the paint or refuse to adhere of which silicone is a known product to fail in both the short-term use and as to longer term-liveability.
The base prep on both surfaces are critical for a 100% bond between the different sub surfaces.
Richard

[boardster]

Just checked those threads, but can't find the answer to another of my Fantastic vent questions:
The rain sensor is covered when the dome closes.
How does it know when the rain has stopped?
It doesn't keep opening a bit and then closing.
Is there another sensor that is still exposed to the moisture?

[Altered Sprinter]

Just checked those threads, but can't find the answer to another of my Fantastic vent questions:
The rain sensor is covered when the dome closes.
How does it know when the rain has stopped?
It doesn't keep opening a bit and then closing.
Is there another sensor that is still exposed to the moisture?
Seek did that thread I think :hmmm: as to A a seal repair and I'm sure he did work or mentioned something about it. try advanced search under Tin write ups.
Richard

[Aqua Puttana]

Anypaws,
I like butyl tape also. Glaziers use it for installing windows. I have also had good success with Sikaflex 291 and Life Caulk. West Marine is convenient and carries both the sealants, but the prices might be better at some other marine stores.

http://www.westmarine.com/1/1/9131-liquid-life-calk-sealant-black-3-oz-from-boat-life.html

Hope this does some good. AP

[bikergar]

Just checked those threads, but can't find the answer to another of my Fantastic vent questions:
The rain sensor is covered when the dome closes.
How does it know when the rain has stopped?
It doesn't keep opening a bit and then closing.
Is there another sensor that is still exposed to the moisture?

Nothing on the outside. I don't know if it is evaporative or timed, but it works. The only problems I have seen with the system is 1, the sensor gets dirty and does not sense rain (a simple cleaning cures this) and 2, on a dewey night with the vent open and the fan not running moisture settles on the sensor and it will close. In a couple of minutes the vent reopens and starts the process over again, and again, and again... If the fan is running this is not a problem as the dew will not settle.

gary

[boardster]

Nothing on the outside. I don't know if it is evaporative or timed, but it works. The only problems I have seen with the system is 1, the sensor gets dirty and does not sense rain (a simple cleaning cures this) and 2, on a dewey night with the vent open and the fan not running moisture settles on the sensor and it will close. In a couple of minutes the vent reopens and starts the process over again, and again, and again... If the fan is running this is not a problem as the dew will not settle.

gary

That's the problem I was having.
Thermostat set at a reasonable level, and morning dew kept the cycling up and down going for hours.
I have two of 'em, and it was a constant dance.
In rain they stay closed all day, and I have'nt figured out how they know.

[CocoaVan]

Run butyl tape under the flange. Once screwed down, I cover the entire flange and screw heads with Parr Parlastic and run the Parlastic out about an inch onto the roof. Parlastic is available in three colors: clear, white & aluminum.
http://www.parrtechllc.com/Datasheets/PARLASTIC.pdf

Another quality sealant used for this application: Sikaflex-721 UV
http://www.sikaindustry.com/pds-ipd-Sikaflex721UV.pdf

Brian

[boardster]

Fantastic recommends sealing each screw w/ silicone, and using their gasket.
I found that the Sportsmobile technique using butyl tape and nothing else works perfect, as the screws are sealed good at the tape.
The trick is to place the tape correctly if roof ridges are in the area.
My rear was done incorrectly, one course only over the large ridges.
I had to re-mount myself rather than make the trip back to Indiana,
but Sportsmobile sent me the tape and told me what to do.

[sikwan]

http://sprinter-source.com/forum/showthread.php?t=1838&highlight=fantastic+fan+leak

Geocel Proflex RV is what I recommend on the caulking. The lap sealant from Dicor is another, but that stuff does not cure hard.

Do not caulk underneath the fan mounting service (service between the fan mount and van roof). Use the foam that Fantastic Fan gives you or maybe the butyl tape that others have recommended (have never used it personally). You want to be able to remove it easily in the future for cleaning and replacing the sealant.