I'm building a Zenith CH750 and it has a central "tunnel" between the seats with control runs inside, etc. The plans call for the top or lid to be riveted in place. The tunnel is not a critical structural member and I have seen others use screws instead of rivets so they can access the area if the need arose. However, I don't know how they secured the screws.

The tunnel sides are 0.025 6061-T6 aluminum. Would it be permissable to drill a hole and attach the top directly with AN sheet metal screws? It would be rare that they would have to be removed, so I'm not concerned about wearing the holes out, etc., ... I'd just like to preserve easy access to the area "just in case".

I know that Tinnerman clips would be an alternative, but I thought one could always resort to that if the holes did strip out too easily. Of course, nutplates would be the ultimate, but it would be pretty labor-intensive to install them ... it's a loooonnnngggg tunnel! HAHA!

Regards,
John