Best Sealant - Geocel vs. Dicor?

[War Eagle]

I'm about to replace the original plumbing roof vent on our 2010 EggCamper with a Camco replacement vent kit (original is chipped, cracked, brittle and chalky). The kit comes with butyl putty tape for mounting, then the instructions say to apply a roof coating round the flange. I was planning to use Geocel ProFlex sealant on the flange, but the local camper repair pro convinced me to buy some Dicor Self-leveling Lap Sealant for the job instead. Now I'm wondering if the Dicor really is that much better or if he just wanted to make another sale. Any recommendations based on personal experience? Another recommendation he made was, if the base of the old flange is still tightly adhered to the camper shell, to just cut the chimney part of the old one off, leaving the old flat flange, and then mount the new kit on top of the old flange and cover the whole thing with sealant. Seems like a short-cut, for sure, but at what cost down the road. Anyone ever heard of such a short-cut - mounting a new vent on top of the old flange?

[Jim G. - Ohio]

Just this summer I installed a full size roof vent on my camper. I'm thinking the instructions from Fantastic Fan said to use Dicor around the edges and on the screw heads. Butyl tape was used between the flange surfaces. The results were impressive. When in the checkout line with the Dicor, another RV'er confirmed the product to be excellent.

[rbryan]

I think either ProFlex or Dicor will do the job. They used ProFlex when they built my Escape and it's holding up very well after almost 3 years.

As for leaving the old flange and mounting a new one on top of it, sounds a bit suspect to me.

[tractors1]

I'm good with Proflex or Dicor, but doing a half of a repair sounds like an attitude (to me) of someone who doesn't really love their trailer and expect it to last 20 years or so.

[LyleB]

Make sure, when buying your Dicor, that you get the proper tube. They make both a one-part and a two-part option of self leveling lap sealant. I almost bought one tube of the two-part option. Lucky for me, a service tech happened to be standing behind the checkout counter talking to someone else when I was paying. Looking at the totality of my purchases, he informed me of my mistake, then took the "wrong" tube back to the shelf and got me the correct one. Thanks General RV in Mt. Clemons, MI. :-)

[Paul O.]

I always have a tube of LEXEL in my Scamp and around the house or garage.

[rbryan]

Originally Posted by Paul O.

I always have a tube of LEXEL in my Scamp and around the house or garage.

I love Lexel, especially the clear for specific applications. Used it to adhere the LED strip under my awning and it works very well. But, I prefer ProFlex for the flange mentioned, because it doesn't set up as quick, and levels better.

[stevebaz]

The part of the old vent that leaks is the base. Putting a new vent on top of a old vent is a bad move. Old vents were mounted on a foam gasket or old putty tape before the use of butyl tape. Gaskets go bad and so does the old putty tape. Big mistake covering up the old with new. Unless you like doing things over every couple of years after the water leak ruins your inside trim.

[Jim Bennett]

I would use Dicor Lap Sealant for any penetration on the roof. ProFlex is great stuff, and I use it sparingly on sidewall penetrations.