NEW! Faster Search Option

Loading
Home › Forums › Fine Woodworking Knots › Joinery

Glue ups?

frostman's picture

Glue ups? (post #170946)

frostman on Tue, 01/08/2013 - 09:20
in

I know that long grain to long grain glue ups are the strongest (say "100"), and end grain to end grain are weak (say "0").

Does anyone know how relatively strong or weak, on my scale of 100 to zero, a long grain to end grain glue up is. I am using hard maple on a tabletop with breadboard ends.

Thanks.

-A +A
RalphBarker's picture

2? ;-) (post #170946, reply #1 of 4)

by RalphBarker in reply to frostman [original] on Wed, 01/09/2013 - 07:26

I wouldn't consider a long grain to end grain glue-up to be "structural" - more of a "hold it in place under minimal stress" sort of joint.

What are you glueing to what?  With breadboard ends, only one small spot in the center, or at one end should be glued, so as to allow for seasonal movement. Often, small wooden pins through an elongated hole in the tenon, are used to hold the M&T joint together.

rev_w's picture

I agree with Ralph on the (post #170946, reply #3 of 4)

by rev_w in reply to RalphBarker [original] on Thu, 01/10/2013 - 07:29

I agree with Ralph on the breadboard edge - sparse amount of glue up in the center of the tenon and the judicious use of pins through the 'top through the mortise into the tenon with elongated holes in the tenon to accommodate seasonal movement.  I use the breadboard edge on the altar tables I build and this technique keeps the tops flat and stable throughout the year - you will notice the changes at the edges of the tabletops - and that is what you should expect. 

frostman's picture

OOPS... (post #170946, reply #4 of 4)

by frostman in reply to rev_w [original] on Tue, 01/15/2013 - 15:53

Thanks. Too late. I glued the whole tenon. We'll see what happens. Hopefully it'll hold long enough...Next time, I know.

Thanks.

oldusty's picture

Bread Board ends (post #170946, reply #2 of 4)

by oldusty in reply to frostman [original] on Wed, 01/09/2013 - 09:01

  With BB ends the tight glue joint and strength derived from it are not the main goal ,

  as has been said the BB end is a method of keeping a solid panel flat and a or

    covering the end grain which adds little structural integrity to the top  typically .

Some styles make the ends of the BB proud of the table top on purpose , then when seasonal

 movement occurs there may be less reference to any movements .

      There are many ways to make BB ends.

      good luck   dusty