For most non-strength required fittings like your lazy jacks (or wire conduit) I suggest that you use aluminum pop rivets. If the block or piece of hardware you are attaching is stainless you should put a plastic washer between the pad of the block and the mast or spreader. Doing this will prevent galvanic corrosion between the hardware and the mast.
For applications where a strong fastener is needed you probably should use stainless machine screws with plenty of anti-corrosion compound (lanocote or tef-gel).
10-29-2009 11:59 PM
Just my opinion: installing mast steps and cheek blocks I used fine thread machine screws (1/4x28tpi). Using rivets makes me nervous-no way to remove easily, no way to check integrity. In thin parent material like a mast or boom, fine threads give a bit more 'grab'. I use SS fasteners with a healthy dose of lanokote for dissimilar metal protection. I also back the fasteners out every couple years and recoat. I tap and thread the holes and avoid the use of sheet metal screws. There are probably as many opinions as people, but that was my conclusion, and it's worked well for me. Good Luck!
10-29-2009 09:57 PM
Preferred method for installing mast hardware?
I've found a few threads on this, but nothing conclusive. I'm planning to install some lazy jacks of some sort, and of course the hardware can be installed by screw, machine screw, or rivet. It seems in the threads I found that stainless rivets are fine for this sort of thing, but am I correct? Are machine screws better for any reason? I don't think I'd go with regular screws.