I need to glue fiber/cement board (Handy board) to a steel frame (1"x1" steel tubing). What glue should I use? Silicon caulk? Liquid nails?
Handy board? Do you mean Hardie Backer? I wouldn't rely on any adhesive to hold such dissimilar materials. Why not flat head screws countersunk in the Hardie Backer through predrilled pilot holes in the tubing? Add construction adhesive if you wish.
Yes, Hardie board. Good point though '78 GT. Easy enough to secure with a few #10 flat head screws with construction adhesive. Better yet, I think pop rivets would be even easier AND I now have one of those pop rivet drill driven installers which are really slick to use.
Yes, why pass up a chance to use a power tool (your cordless), and no wait for curing time. Good luck with your project, Clark!