What is the best 'topical' sealant for exterior panel joins?

[GeoffL]

Some of the sealant (which looks like a bead of clear silicone) over the horizontal panel joins on the sides of my 2001 Autotrail Scout coachbuilt is coming away. I suspect this sealant isn't original and was applied at some point to ensure no water ingress through the panel joins. The concensus in this thread is that silicone isn't the right sealant for this purpose. As I'm not going to be able to separate the panels to apply mastic or other sealant at the overlap, I need something that I can apply as a thin bead over the join and would welcome recommendations.

Thanks for looking, Geoff

 

[nabsim]

I would be looking at Sikaflex-521 UV

I would probably email Sika tech support and ask them first to make sure, that’s what I did when I fitted my solar

 

[GeoffL]

I would be looking at Sikaflex-521 UV

I would probably email Sika tech support and ask them first to make sure, that’s what I did when I fitted my solar

Many thanks. Asking Sika is probably a good idea.