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Fantastic fan/vent is leaking!
I installed a fantastic fan/vent in the roof of my van.. I used silicone on the roof(outside) and silicone around the vent on the inside of the van before I put y finishing materials on.
Anyway, it’s leaking really bad.
Does anyone know of a product that would work well for fixing the leak?
I don’t care if it looks like crap. I plan on just adding some product(silicone, or other) to the outside since the inside is covered up.
What about jb weld or something similar?
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Can you tell exactly where the water is getting in? Is the rubber seal there and seated properly between the lid and base? Get up there and look closely for cracks in the plastic.

If it is coming in around the edges, the best thing would be to uninstall it, scrape off all of the silicone, and install it properly with butyl tape. If you cannot do that, I guess more silicone would be the next best thing, paying attention to the mounting holes.
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Yes unfortunately anything touched by silicon is very very difficult to use something else on later, nothing's going to want to stick to it now.

Should have been done properly with butyl tape to start.

I would completely remove the vent, really grind/sand solvent? off all traces of the silicon from every surface it touched, maybe even glidden gripper prime all silicon touched surfaces as well.

Then re-install properly using good butyl tape

The best butyl tape is Bed-It

Good HowTo here

I'm sure others will have easier solutions, but maybe will require attention again, while the above should be good for many years, assuming the roof itself is sound.
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The following 1 user says Thank You to John61CT for this post:
frater secessus (12-27-2017)
needs to be redone without silicone and all traces of silicone must be removed. mount it with butyl tape and then use Dicor self leveling sealant. highdesertranger
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The following 1 user says Thank You to highdesertranger for this post:
frater secessus (12-27-2017)
I agree that the best solution involves removing and reinstalling the vent.
 Silicon (hate the stuff!) should never be used anywhere but most of us have made the mistake of using it and paid the consequences.

One seam on our RV was sealed with silicon and the joint opened a bit so it had to resealed. We found a new product that is supposed to stick to existing silicon caulk and tried it. It seems to have worked but since it's only been on for a few days, the jury is still out.

 It's sold as bathroom and kitchen caulk but is good for a wide range of temperatures so should be fine for exterior applications-
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Not silicon.

lol....different stuff!

Hey if that roof is not flat and is fluted or corrugated, (ribs)...then yes it will leak. Eventually. No matter what you do.
About to be 'vanless' after FOUR years...
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once vent is installed I wouldnt take it back out, jb weld will work extremely well but it would be an expensive fix.
How about hotglue? I use that to build my swampcoolers and even in the areas were its always in water it
never comes off, I have to use a putty knife to remove it when I tear the swampcoolers apart.
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You don`t ever use silicone when installing any type of roof vent on an rv or van, unless you want a leak.
You need to remove the vent, clean every bit of silicone off of the roof and the vent and start over.

You will need some Butyl tape and some Dicor to do the vent installation correctly.
I have installed two fantastic fan vents and one regular vent in my rv, and have never
had a leak from any of them.
1984 Cobra Class C 26'
On E 350 Chassis 
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I pulled my old one, cleaned.scraped.sanded.repainted, then put down butyl tape, installed my fan, then went over all the seams with 4" Eternabond tape. bone dry
There is a difference between my personality and my attitude.
My personality is who I am, my attitude depends on who you are.

2 amazing dogs and Miles the 1987 Dodge B250
I live in the Uncanny Valley
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The following 2 users say Thank You to GypsyDogs for this post:
frater secessus (12-27-2017), Oberneldon (12-21-2017)
Just wanted to thank everyone for the help. I pulled my fan out. Scraped the old silicone. Reinstalled with butyl tape. It’s been raining like a SOB and it hasn’t leaked a bit.
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The following 2 users say Thank You to Kenny P for this post:
John61CT (01-31-2018), highdesertranger (01-31-2018)

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