Any one with experience of screwing...

into conservatory

I want to mount some LED strips:

https://www.marcled.com/products/216...567891033.html

onto the plastic "cove" that runs under the roof.


2 options, having pulled one off: It's very heavy gauge uPVC that
"plugs" into a moulding in the ali frame.

1) Coarse self tapper into the plastic (about 1/2" clearance behind)

2) Or straight through into the ali. I think it's a big hollow section,
about 2" thick. Certainly clear of the glass by miles. Should be safe to
screw into.


So what screws?

https://www.marcled.com/raw-aluminiu...349878900.html

is what I actually have to fix. So we cannot go too massive with the
screw. Roughly the equivalent of a 5mm "goldscrew" would be OK.


Would stainless self tappers cope with aluminium? I'd like them not to
rust in place over time.

Or is there are particularly coarse threaded screw that would work will
in uPVC? The weight supported is very low.


Or indeed, option 3 that I just thought of: is it hard to hand-tap a
machine thread into 2-3mm thick ali?



Asking, because I'd like to not make a mess of this!

Cheers, Tim