main rigging on 20 ft oday?

[salvo]

went out the first time got most of rigging.cant figure out the boom vang. and when the sail has no wind the boom will sit in your lap boom is at negitive must be missing something

[siamese]

Regarding the boom sitting in your lap, maybe it's just affectionate. But seriously, you're missing your topping lift. As you google "topping lift" to get an ideal of how you'll want to rig yours, you'll discover that it's a line that runs from the top of your mast to the aft and of your boom. Keeps the boom from falling.

You could have a topping lift that goes from the end of your boom, to the top of the mast, through a sheeve, down to the base of the mast ,where it could terminate at a cleat, or you could have a block at the end bottom of the mast, and run the line to the cockpit where it would terminate at a cleat or other piece of hardware of your choosing.

Me, I'd just run it from the top of the mast to the end of the boom, and keep it simple. One way is just to have a cleat on the boom to allow you to vary the length of the topping lift, depending on whether you're under sail (keep it longer so as to avoid fouling the leach of the sail and/or having your boom too high), or shorter (when your not sailing and you'd like the boom a little higher so it's not in your way).