Constructing a table top

[whk]

I'm making a simple tabletop out of ipe left over from a deck.  I've attached the lengthwise boards to each other with pocket screws, and now I'm trying to think of a good way of attaching the end boards.  I don't think ipe changes much in size with humidity, so I'm tempted to attach the end boards with more pocket screws.  I could borrow a Domino and maybe use it somehow.  I guess my question is, do I need to build some sort of flexibility into the table top to account for expansion, and if so, how do I do it?

Will

 

[CharlesWilson]

Ipe's change in size due to moisture is not all that different from that of white oak.

You might try pocket screws on the ends, but make the entry holes larger as you get away from the center of the end boards. I suspect that you will have some difficulty gluing to ipe, so pocket screws may be your best choice. You could use dominos as alignment aids without glue (with wider slots on the end-boards away from the center). Use the new dominos made for outdoor use, and they might last a few years (not as long as the ipe).

You didn't say if you used stainless pocket screws, but considering the life expectancy of the ipe boards, you might consider changing out the ones you already used with either stainless or an epoxy coating.

Charles

 

[PaulMarcel]

You didn't say if you used stainless pocket screws, but considering the life expectancy of the ipe boards, you might consider changing out the ones you already used with either stainless or an epoxy coating.

The time I used the stainless steel pocket screws on a project, they seemed to snap pretty easily.  Since Ip? is pretty hard, maybe putting in a tougher screw first to clear the hole might not be a bad idea.  Then put in the stainless steel screw.

 

[Jesse Cloud]

The end boards, "Breadboards" will need to be attached in a way that allows the long boards to move.  I used this technique on my 30 inch wide walnut dining table and the wood expands about 1/2 inch from min (dry winter air) to max (humid swamp cooler air).

The traditional method is to cut a long stopped mortise in the breadboard and an equivalent tenon in the main assembly.  The tenon is pegged with three wooden pegs.  The middle peg is glued and fixed.  The end pegs are not glued and ride in slots in the tenon.

The pocket-screws-in-slots method above would work if the breadboards don't get a lot of downward pressure.

The other approach is to just leave the end grain visible, maybe softened with a chamfer.

Hope this helps...