Best Silicon to use on roof top vents Please

Rick-N-Lesleigh · Member

Best Silicon to use on roof top vents Please

Aus-Kiwi · Guru

Sikoflex . Seals, adheres better and can be painted over . Sets like rubber .

Rick-N-Lesleigh · Member

Thanks Aus-Kiwi

Peter_n_Margaret · Guru

Silicone is banned on my vehicle.
Another vote for Sikaflex. There are several grades that would be suitable. "Construction AP" is probably the cheapest, or "Pro".
If you want to avoid using screws, use "11FC" which will both adhere and seal.
Cheers,
Peter

Greg 1 · Guru

Totally agree with the other comments. Plastics and silicones are incompatible and the bond will let go at some point. A polyurethane sealant, such as the Sika products mentioned, is the go.

KJB · Guru

What ever version suits so long as it is Sikaflex....

Cupie · Guru

Peter_n_Margaret wrote:
Silicone is banned on my vehicle.
Another vote for Sikaflex. There are several grades that would be suitable. "Construction AP" is probably the cheapest, or "Pro".
If you want to avoid using screws, use "11FC" which will both adhere and seal.
Cheers,
Peter

Agree .. I'd not worry about any tiny cost factor & go for the 11FC.

Be very careful to mask the area & make a nice neat job using silicon scraper tools.

You can remove the old adhesive and key the surface with nylon discs in an electric drill.

Perhaps the use of the term 'Silicon' was similar to saying "I need to get some 'petrol' " when we might mean Diesel.

Mike Harding · Guru

Note that Sikaflex 11FC has a shelf life from production of only one year so check the pack date before purchase:

http://aus.sika.com/dms/getredirect.get/au01.webdms.sika.com/104

Rick-N-Lesleigh · Member

That's for the replies, and yes I was using the term "Silicon" as a Generic word for Sealants and adhesives.
I will look into the Sikaflex 11 FC, I am also looking at a product called "Eternabond", anyone here used that.

Whenarewethere · Guru

Have used some Sikaflex on the car.

Those silicone tools are brilliant for nice tidy edges, cut them to size of needed. Get yourself organised so you can clean the edges as quick as possible before it starts forming a skin.

Cupie · Guru

Whenarewethere wrote:
Have used some Sikaflex on the car.
Those silicone tools are brilliant for nice tidy edges, cut them to size of needed. Get yourself organised so you can clean the edges as quick as possible before it starts forming a skin.

Yes, I agree. It makes you wonder just how much training some of those Caravan manufacturing assemblers are given when you look at the frequently terrible sloppy jobs that they turn out.

I was given a short lesson by a repairer in Caboolture, when I went up there to purchase a box of sealant/adhesive from them. Even got to watch one of their craftsmen who coincidently, was applying a bead when I was there.

I have a carton beside me to wipe off excess onto its insides as I go & to deposit masking tape as I remove it. Lots of small rags to clean hands & tools etc go in there too.

BAZZA44 · Senior Member

To tool off 11fc, have some turps in a spray bottle and when ready to clean off excess, lightly spray over the 11fc and on your spatula and them remove what is needed.

This will give smooth finish to edges. Similar to using soapy water on silicone.

Barry

Jaybird · Veteran Member

I've sealed the whole of the roof and vents in my Jayco Discovery with Eternabond as a precautionary measure, it has been on for a while now and there is no sign of any deterioration After reading lots about leaking vans I didnt trust the manufacturers so decided to make sure myself. Eternabond has been around a long time and is used a lot in the construction industry and RV building in the USA.

If you use it make sure to follow all the instructions, do not stretch it when applying just lay it down as you go then give it a good go with a roller. If it sticks and you have got it wrong its too late because you wont pull it back off. I marked a line with a pencil along the roof that I wanted the edge of the tape to follow and peeled off the backing tape about 300mm at a time and laid it along the line. I put along all edges and around the rectangular hatches and used sikaflex on the TV antenna as its base is circular. Have a good read of their web site as it has good videos.

https://foamsealant.com.au/eternabond/

-- Edited by Jaybird on Wednesday 11th of March 2020 11:51:59 AM

swamp · Senior Member

Hi
I suppose that's why SIKA manufacture SIKASIL . Oh yea its meant for main use RV--Industrial .. Specifically mentions RV body assembly .
Silicon is far easier to remove than urethane such as Sika-flex
Silicon is far more flexible than urethane

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