connecting z-frame T&G doors

[MarkAndDebbie]

While it rains this next week and my transmission gets replaced I will be working at home instead of on-site.

I'd like to build some z-framed doors. I have some 8' 2"x6" SYP T&G boards. They are twisting before my eyes - so I'd like to try and get them together (I also talked Debbie into letting me keep them in the livingroom to try and control the moisture - that won't last long ). So I know to put the bottom of the Z on the hinge side (from the barns and outbuildings book), but I don't know how I should keep  the boards together.

I thought about drilling two holes in each (top and bottom) and putting a carriage bolt from outside - in through the horizontal parts of the Z. Forsner bit on the inside. 2x material for the Z. 2.5 inch bolts to recess them. Paint the bolt heads black before assembly.

1. Should I glue them?
2. Should I forget the bolts and just screw them from the Z side (looked like maybe what NH Dave did) http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1147990285/93#93
3. I got the zinc plated ones - I saw someone with galvanized here torch them. What effect (visual) would that have? What affect structurally/rusting would that have?
4. I got carriage bolts because Debbie liked the round head look better than hex. should I switch to a hex with a washer?
5. Any tips?

Thanks for your thoughts.

[MountainDon]

Through bolting would work. One potential downside is that each one will be a cold point, on the inside, that will frost up in cold weather if the interior humidity and warmth is in the right zone. (Personal experience).

I see nothing wrong with using carriage bolts. The round heads are visually nice. I also like CB's because I don't need a helper on the other side of the door or whatever to hold the other wrench.

CB's bite into most woods quite fine as long as you don't use too of an arm when tightening them.    I literally used a ton of carriage bolts when I was manufacturing wood playground equipment. Seldom had any turn if the bolts weren't overtightened. If they do turn there are barbed washers available. They have cut and folded over barbs to engage the wood and a square hole to engage the CB.  

If you do use CB's you can dress up the interior side a little by using acorn nuts, if you get the bolts just the right length.

Glue? If you mean gluing the T&G joint I wouldn't bother. The wood will expand and shrink with humidity changes. I wouldn't glue the Z to the vertical door boards either. Same as above & if you ever did have to do any dismantling for any reason that would complicate things.

JMO

Looks like NH Dave through bolted the hinges only. That might be a better approach to reduce the number of potential cold points.

If you don't like the shiny zinc look you could always prep, prime and paint them. Once again, IF frost/moisture is a potential problem you might want to keep the plating to discourage rust.