Breadboard Question

[Matt]

It has been a while since I have been on this board, miss you guys. Work and hunting season have conspired to keep me out of the shop...

Anyway, I am getting back to work on a hall table. It is ambrosia maple with breadboard ends (my first attempt at breadboard ends). There is a 3/4" strip of walnut running cross grain to the main table portion at the start of the breadboards. I have routed a 1/2" wide x 1" deep groove in the walnut / maple end and now need to connect it to the main table. The top will be 13" x 39". Questions;

1. I know to only glue the "tongue" in the center or on one end (I was planning the center). Should I also put pegs in the ends with an oval hole in the tongue to help secure the end?

2. The groove is about 11 1/2" long and I was planning on a 10" or so tongue. How large an area should I glue in the center?

3. To cut the tongues out, I was planning to run a cut with the table saw (the table saw gives me better control) and then route the rest with a straight bit. Good idea or is there a better way?

Thanks for the help! and yes, pics to follow when finished...

 

[Monty]

1. I know to only glue the "tongue" in the center or on one end (I was planning the center). Should I also put pegs in the ends with an oval hole in the tongue to help secure the end?

I would think so, otherwise you'll see a gap over time (although this might not be as much of an issue if you're gluing the center of the tenon.... :eusa_thin ). If you don't want it to show, I suppose you could just drill through the bottom of the breadboard, assuming your mortise walls are thick enough to support it.


2. The groove is about 11 1/2" long and I was planning on a 10" or so tongue. How large an area should I glue in the center?

About 4" or so should be just fine.


3. To cut the tongues out, I was planning to run a cut with the table saw (the table saw gives me better control) and then route the rest with a straight bit. Good idea or is there a better way?

I just made a guide to clamp on the end of the table, to act as a straightedge for the router. The top and bottom edges are aligned, and the spacer blocks on each end are glued in place to keep everything aligned. Start routing along the very end and work your way back with several passes until you run along the straightedge guide on your last pass. Clamp a piece of scrap to the right end of the board to prevent tearout on that side.

 

[Monty]

One other thing... if your table top is 13" but your tenon is only 10" long, that leaves 1½" unsupported at either end where the table top and the ends of the breadboard might not be perfectly flush over time. I would consider making that tenon longer.

 

[Matt]

Don't I need to leave room in the mortise for the tenon to expand / contract? How much room should I leave? If I make the tenon longer, I am afraid of blowing out the ends of the mortise if I get too close to the edge. What is a reasonable distance?

Thanks again!

 

[Monty]

I wouldn't think it would need more than about 1/4" on either side (1/2" total across the panel). See what others think...

 

[walnutjerry]

Don't I need to leave room in the mortise for the tenon to expand / contract? How much room should I leave? If I make the tenon longer, I am afraid of blowing out the ends of the mortise if I get too close to the edge. What is a reasonable distance?

Thanks again!

Matt-------There is not near as much movement lengthwise in wood as there is across the grain. Thus, the main part of the top will move more than the breadboard ends.

I have used a sliding dovetail for breadboard ends and fastened them at one end only. No glue at all. That was on a lid for a blanket chest and I chose to fasten on the front corners for asthetics and any movement differentials would be on the back side of the lid. The dovetail method also helps control any cupping that might occur in the lid.

Just one more way of doing it.

Jerry

 

[rhett]

You may want to make your ends 1/16+ longer than the width of the table. The top will inevitably expand. If the ends are equal to the width, the top will grow past the ends.