Domino Selection Quandary

[btschmid]

So I just picked up the Domino XL and for my first big project am making a large outdoor white oak table.  The slats for the table top will be 174mm wide by 45mm thick.  The thickness calls for a 14mm tenon, but the width complicates it.  Factoring in double the tenon thickness between dominoes as recommended by Festool, 3 dominoes would leave too little substrate at each end of the board, while 2 does not seem strong enough to me.  I could use 12mm and fit 3 dominoes comfortably, but they seem a little too thin.  Am I just over analysing this?  Thank you all for any input you might have.

 

[sancho57]

Yea yer over thinking it IMO.

I do the same thing

 

[Birdhunter]

I’ve read the post three times and I’m confused. I can’t picture what the OP is asking.

 

[btschmid]

I’ve read the post three times and I’m confused. I can’t picture what the OP is asking.

Sorry for the confusion.  Basically slats will be dominoed into a perpendicular piece.  I'm worried that using three 14 mm dominoes will only leave about 17mm between the edge of the slat and the edge of the outermost dominoes in each piece.

Festool recommends twice the domino thickness between dominoes to leave enough wood to support the joint.  I'm not sure if the same recommendation applies to the distance between the edge of a board and the edge of the domino.

 

[Sanderxpander]

It's still 45mm thick oak, I doubt there'd be a problem whichever of the two proposed options you use.

 

[ear3]

As the boards are a little less than 7 inches wide, two 14mm dominoes should be more than enough to anchor them.

 

[Trosey]

Outdoor---use Sipo dominos

Buy the 750 mm ones....much less expensive (did not say cheap)

Use as long as material will support.

 

[James Carriere]

I’ve read the post three times and I’m confused. I can’t picture what the OP is asking.

Sorry for the confusion.  Basically slats will be dominoed into a perpendicular piece.  I'm worried that using three 14 mm dominoes will only leave about 17mm between the edge of the slat and the edge of the outermost dominoes in each piece.

Festool recommends twice the domino thickness between dominoes to leave enough wood to support the joint.  I'm not sure if the same recommendation applies to the distance between the edge of a board and the edge of the domino.

This week Festool announced a redesigned fence for the Domino 500 which has the capability to set the "center" of the domino closest to the edge of the work piece at 20mm.  While I realize you have an XL, placing the edge of the domino at 17mm from the edge of the work piece should be fine.  As well, the double domino thickness to the edge of the work piece on the XL does not apply as the built in stops easily allow a much closer placement to the edge of the workpiece.  You should be fine with two dominos per slat but have enough space to use three if you prefer.

+1 on the Sipo dominos comment by Trosey.