# overwiping new sealant onto old



## VEEBUG74 (Apr 22, 2011)

have the relavant sikaflex sealant,just basically wondered if i could top up origional sealant?,as i dont want to hack out old ideally


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## cabby (May 14, 2005)

that is a big no no.you must get out as much as is possible of the old stuff, before you even think about putting on a new run.

cabby


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## DTPCHEMICALS (Jul 24, 2006)

As above.

But you could always try it and let us know how you get on.

Dave p


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## inkey-2008 (May 24, 2008)

I would go with cabby a big no no. But you dont have to remove the roof light or bead just remove all the old sealant and put a new bead up to it. make sure you clean off all theold stuff and the surface is nice and clean. 
You can run masking tape either side of the area to be sealed and remove while still wet for a nice clean finish. Dont over work the sealant when you have a applied it.

Andy


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## EJB (Aug 25, 2007)

All types of silicon based sealants will *not* adhere to old, or even new, sealents once they have set.
I assume this will also apply to sikaflex....although I stand to be corrected for that particular trade name. :wink:


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## VEEBUG74 (Apr 22, 2011)

thanks guys will give it a swerve for now


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## lesanne (May 1, 2008)

Hi, been there ,done that .i tried re/sealing a couple of roof lights this year using sikoflex without removing all old filler .worked for a while untill the sun got to them ,they then started to peel and seperate ..ended up changing all three of mine to be sure..of good seals..Les.


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