Thanks everyone!!!!
Amazing how easy it is to get professional
help on the net!
I`ll go for the self tappers and the sikaflex. I talked to a boatseller here and their mecanics said they would use sikaflex 291. Is that sufficient combined with the tappers, 5.5 mm or should I go for 292?
Thanks and regards
Lennnart and Fredrik, the latter is the son who's doing the job