Roof vent leak

[wheelerimage]

An RV service place sealed the seams around my roof vents with a white material that I believe is good for most RVs. After a year, I am starting to get some leaking there. I added some Silicone which stopped the leaks.

I have since learned that silicone doesent work on aluminum and that I should have used Vulkem. I also sealed my fridge vent with silicone.

Can I put Vulkem over these other materials, or do I need to strip the old sealant first?

[vswingfield]

Remove the silicone. Vintage Trailer Supply has a Silicone Caulk Remover. I bought a small tube instead of the large one for use with a caulking gun. It works but it is still work getting the silicone off. Then you can get Vulkem to adhere properly.

[Minno]

Yes, remove the silicone. Vulkum will not adhere to silicone. Actually, I'm not sure vulkum will adhere to the white stuff either. I'd do a test.

[vswingfield]

Originally Posted by Minno

...Actually, I'm not sure vulkum will adhere to the white stuff either. I'd do a test.

Good point. Clean surfaces are best for just about everything. True for paint and sealers, prep is the most important part.

[NJtoNC]

forgive the question here but... why does silicone not work on aluminum?

[Minno]

Silicone will EAT aluminum over time. We removed a TV antennae from our Little Girl that had been sealed with silicone years ago. The aluminum had corroded and thinned out to the point that we had to patch it.

Kay

[Don.44]

Does anyone used Kool Seal to paint around the vents to seal them I use to use them on my old camper on the seams and it seamed to work well but I don't hear it mentioned any more ?
Don

[Inland RV Center, In]

Originally Posted by Don.44

Does anyone used Kool Seal to paint around the vents to seal them I use to use them on my old camper on the seams and it seamed to work well but I don't hear it mentioned any more ?
Don

Use Vulkem or Sikoflex, "ONLY".

Use what is known to work, instead of guessing.

Andy

[blickcd]

How about Parbond? I've always heard that was okay too, and it works well.

Christopher

[Smokin Camel]

Parabond is a bit stiff for that area. Sikaflex221 or the 3M butyl salnts will flow into the seam. Vulkem doesn't flow much, but it seems to work on almost any metal sealing job. Andy gave good advice fir roof vents. Stiff areas such as by windows and so forth Parabond does well. Some use Dicor, I have no experience with Dicor. take your time, butyl sealants can be a bit unforgiving and it takes a bit to clean up smears and so forth.

When I installed my Fantastick vents I used Sikaflex. A week or two later I put a bead of Vulkem over the Sikaflex as it wicked in really good and I wanted an exterior bead to smooth the seal off.

[Steamy1]

I did use Kool Seal (Kool Seal® Premium White Elastomeric Roof Coat) around the Fantastic Fan to repair a leak that was allowing water to enter and dripping inside. However, I masked the metal so that I was only applying it over the existing white sealer, which was somewhat cracked. It seems to have done a good job in filling in the cracks and the leaking stopped. I used a 1" paint brush and lightly painted over the existing caulking material.

I was abbout to leave on a trip and did not have the time or desire to strip off the existing caulking, pull out the fan and completly re-do it entirely.

I have not used Kool Seal directly on the metal.

Personally, I am a fan of Kool Seal.

[Mexray]

I've also used EternaBond 'tape' for a quick fix - even got it with alum on top for good match with the alum roof skin... It works best when the roof is warm so the sticky stuff can flow a bit...)

[Don.44]

Have you seen that stuff advertised on TV that they spray on a screen door , that covers the bottom of a boat then they go fishing ? Well that's the stuff I think we should use ... I wonder if they have it in White or Silver too ?
Don