Community Forums

chunker · 03-04-2018, 05:33 PM

I am replacing 2 vents with the fantastic fan and off course there is butyl putty and some form of lap sealant. Roof is EPDM and the sealant could be Dicor Lap sealant or Alpha Systems sealant. No way to know which one. It's impossible to get all the sealant off but I'm getting off what I can. Are the 2 sealants compatible? I have one tube of Dicor self leveling lap sealant and 2 tubes of the CW version, Super Flex by Alpha Systems, also self leveling. From one of the vents I'l be running a 4" strip of Eternabond from the vent edge to the side wall to fix a small hole and a suspect previous repair.

I have searched for articles or company statement about that compatibility but can't find any. Sealant is white and very little will be left but I want to make sure that there isn't a problem. I will be using some brake cleaner on the sealant to get as much off and follow up with a god clean water rinse.

On the eternabond repair I also have some eternabond primer coming which I will use.

cruzbill · 03-04-2018, 05:45 PM

I would just use Dicor, I've pulled and recaulked several fans /vents and the self-leveling Dicor works great. I wouldn't worry about compatibility unless you get a whiff of pre-existing silicone. As far as a solvent, no petroleum based stuff on a rubber (EPDM) roof. I just used elbow grease and a warm day, all came off clean.

chunker · 03-04-2018, 06:05 PM

Quote:

Originally Posted by cruzbill

I would just use Dicor, I've pulled and recaulked several fans /vents and the self-leveling Dicor works great. I wouldn't worry about compatibility unless you get a whiff of pre-existing silicone. As far as a solvent, no petroleum based stuff on a rubber (EPDM) roof. I just used elbow grease and a warm day, all came off clean.

The brake cleaner didn't indicate a petroleum base and yes I want to avoid that. Been doing a bunch of reading and a few purported RV gurus indicate that brief exposure to a petroleum product won't hurt, emphasis on brief not bathing in it. Brake cleaner was mentioned several times as a good cleaner and in fact it worked well on my shoes. In fact the Dicor has petroleum distillates in it. On their web site they say that it evaporates during the curing. Go figure.

No silicone fortunately.

Since I will have 2 vents to seal up, my inclination is to use the Alpha product so I don't mix products in the job.

**Spdracr39** · 03-05-2018, 07:48 AM

It does not have to be 100% clean. The most important is to get off all of the butyl tape and have a really clean area for the new butyl tape to go down under the flange. If the old dicor outside of that is in good shape leave it. I cleaned mine with mineral spirits poured lightly onto a rag then put down the butyl tape, installed the flange. then dicor self leveling over the top of the screw heads and along the seams. The whole process took about 2 hours. DO NOT SPILL petroleum based solvent on the roof material it will damage it.