I want to build a table

[Ianab]

Are you also suggesting that allowing the cup to accumulate won't present a problem with the top?

It shouldn't be great as long as both sides of the top are finished in a similar way. You don't need to get a perfect finish on the underside, but make sure it gets a couple of coats of varnish. That keeps both sides changing in moisture in a similar way. The cupping from that is only temporary, but can be quite extreme if the weather changes.

Also, even cupping over the whole top can be controlled by the apron that's supporting the table. (Sliding tabs, slotted screws etc) Alternating cupping of each board gives smaller movement, but a washboard effect that you may be able to see or feel, but can't be controlled.

I glued up a top out of eucalyptus for a little bedside cabinet, and left it leaning against the shed door (inside). Overnight it rained and some water seeped under the door, never reached the piece, but the humidity made it cup about 2" over a 20" wide piece. I look at it and say "Crud, what do I do now?"  I turned it around and leant the other side against the door.  Next day it was straight again, the moisture had evened out. So the changes can be that fast in unfinished wood. Likewise if you finish one side, and not the other, the unfinished side can move that fast, while moisture transfer on the finished side may be 10X slower.

Ian

[WDH]

I used to alternate the growth ring pattern (bark side up, bark side down), but I quit doing that and started just picking and matching the best faces.  I have not had any issues, mostly, like SD said, because of proper attachment at the proper time. 

[Ironwood]

Putting the same finish (type and number of coats) on each side is technically, creating a balanced "moisture exclusivity". I dont get to carried away with the grain direction, although my tops are 1.5"-2" and pretty heavy. I use heavy walled steel box tube recessed in the underside for dimensional stability.

One inch stock is pretty reactionary, and can move a good bit especially if not completely dry. Even if your permanent cleats arent done use some "waste" ones until yours are done. The grain vertically is /alot stronger than laid flat. So, orient your cleat grain accordingly.

I have done some REALLY big glue ups and used vertically grained (quarter sawn), but the grain is fairly unimpressive if it isnt something that will show fleck/ray (white oak) or curly (maple etc,...).



Also, using threaded inserts instead of simple screws will create a TON more holding power if it DOES want move. The circumference of the insert has a multiplying effect due it's surface area in contact with the wood.


Ironwood