# would you screw? the outside of a fiamma crystal vent



## 100996 (Sep 15, 2006)

Hi All,

I am in the process of replacing an old and warped MPK roof vent with a Fiamma crystal roof vent. 

I have procured a tube of Sikaflex 512 (for caravans apparently) for the sticking and sealing of it, but the outside frame of the vent has 20 holes for screws. 

SO would you screw it down as well as using sikaflex? and the internal screws? or would you just sikaflex and internally screw it? 

I know I need to leave a good bead of sikaflex round it so will be standing it off by a couple of mm with some thin lath type wood.

Answer soon would be great as I need to fit it in the morning.

Chris


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## richardjames (Feb 1, 2006)

What material is the roof?
Richard


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## 100996 (Sep 15, 2006)

richardjames said:


> What material is the roof?
> Richard


aluminium over ply.

Chris


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## richardjames (Feb 1, 2006)

I personally think that stainless steel selftappers should be fine as long as the threads ar covered in the sealant - my roof vents are screwed down onto ally/ply
Richard


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## 100996 (Sep 15, 2006)

richardjames said:


> I personally think that stainless steel selftappers should be fine as long as the threads ar covered in the sealant - my roof vents are screwed down onto ally/ply
> Richard


Thanks Richard,

I thought about stainless screws, but as I have had boats in the past, was a little worried about galvanic corrosion....

Do you have any thoughts ?

Chris


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## richardjames (Feb 1, 2006)

I thought galvanic corrosion was only to do with sea water - I have been involved with boating - put together a 30ft cruiser in the back garden and used to build traditional skiffs. By covering the screw with the sealant creates a barrier/gasket anyway
Richard


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## gaspode (May 9, 2005)

Absolutely no need whatsoever to screw it down in my opinion.

Secured a Maxview satellite dish to out last van with Sikaflex 512 and no screws, suck like muck to a blanket at 70mph on the motorways.

If you've ever tried to remove anything fixed with Sikaflex 512 you'll never feel the need for screws again. :wink: 

Don't forget, they use a very similar adhesive to fasten many car body panels together these days (and of course all the glass into modern cars).


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## mangothemadmonk (Aug 6, 2006)

I wouldn't bother with screws. Sikaflex sticks like the proverbial. Just put plenty on and make sure it squeezes out when bedding down.

Johnny F


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## richardjames (Feb 1, 2006)

Tell me why do the manufacturers use screws?
Richard


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## mangothemadmonk (Aug 6, 2006)

richardjames said:


> Tell me why do the manufacturers use screws


Doc Martin glued the soles of my shoes on and they haven't come off yet!

Johnny F


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## 100996 (Sep 15, 2006)

mangothemadmonk said:


> I wouldn't bother with screws. Sikaflex sticks like the proverbial. Just put plenty on and make sure it squeezes out when bedding down.
> 
> Johnny F


Thanks guys,

Reading the sikaflex tube it says leave a 2mm minimum bed for the sikaflex. What are your thoughts? I can stand it off on some stainless washers, but i am not sure it is required again you help gratefully recieved.

Chris


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## mangothemadmonk (Aug 6, 2006)

I wouldn't put anything else between the roof and the vent, just sealant.

I think it is just saying put a minimum of a 2mm bead. Put plenty on and squeeze down.

Make sure all is clean and dry first and free from grease.

Johnny F


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## 100996 (Sep 15, 2006)

mangothemadmonk said:


> I wouldn't put anything else between the roof and the vent, just sealant.
> 
> I think it is just saying put a minimum of a 2mm bead. Put plenty on and squeeze down.
> 
> ...


Right, it's done, I hope this is the end of the leaky roof vents.

Put bundles on, and pulled it all well down, then smoothed off the excess with me finger.

I spose the question now is how the hell do i get this stuff off my hands??

LOLOLOLOLOLOLOLOL

Thanks for the help guys.

Chris


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