I used Sikaflex 292i which is a marine adhesive when fitting an additional panel to my Pilote c class. This was after speaking to Pilote and 2 companies that install panels.
Edina makes a great point. You ask about what type of sealer. As Edina points out go by manufactures instructions ie. What primer/adhesive thay recommend before bonding it on. It might be some people know better than the manufacturer. It really is a science. So for someone like me. I will take thr knowledge on board
The paint issue is one I never thought about, and just used stixall on all of mine bar my first van which I used roofing screws as well, 8 vans no problems, but can't speak to longevity, you do have to ensure chemical cleanliness and to ensure 1mm thickness under the brackets, use a short bit of 1mm wire, all but one of my vans were pre 07, the last being a 07 Relay, that was built in 2011 and as of late last year all roof fixtures were sound bar the heki 2, a small leak but I think this may be my fitting as I hurried it.
Make sure you key the brackets as well as the roof. The minimum thickness is 2mm, so I generally use 3mm tile spacers for optimal bonding. Too thick or too thin can cause the adhesion to fail. If the panel is in a position where it is likely to have a powerful airflow hitting it whilst driving, as an example, if it was over the cab, fit a wind deflector. I used a piece of aluminium angle. The other forces from cornering, braking, acceleration, bumps and gravity effect the vehicle and panel equally so they are not a concern.
Look closely at that video and you will see that the panel was bolted, the bolts are still protruding from the mounting brackets. I guess the bolts ripped out of the roof?
Tragedy Narrowly Avoided: Caravan Solar Panel Comes Adrift
Many caravans have solar panels on their roofs - but not all of these panels are properly affixed. This video shows what can happen.www.solarquotes.com.au
