Mid ship cleats mounting; how to , B 30 -06

[Kvaere]

Instructions needed,  do I need a Tap & Die Set.
Never used one before
Cleats are Pfeiffer Marin 26 cm I understood screws should be 8mm, but length?.

Is it a metal plate hidden there?
 

Bavaria 30 Cruiser
2006


 

[symphony2]

I expect there are aluminium plates bonded in there. You can check by using one of those metal detectors for finding hidden pipes and cables in house walls. M8 sounds correct. As for length probably 20mm longer than the depth of the holes in the cleat, but siggest you wait until you have drilled and tapped the hole. Use plenty of polyurethane sealer when you assemble, including on the threads to isolate them from the aluminium.

[Kvaere]

Thanks

So I have to ask, screw 8mm so I drill a 8 mm hole and then make threads ?

What about Butyl can I use that?

[symphony2]

No you need to use a tapping bit first (from memory it is 6.8mm - but just ask for an 8mm tapping bit). Butyl is fine - just that polyurethane also has adhesive properties as well as sealer.

[Kvaere]

ok

I guess no washers needed?