I consider a spline a floating stub M&T joint...

what do y'all say about them...

how many of ya use them..

 

 

Edited September 14, 20169 yr by Stick486

I have used them a few times.  I even used them in mitered box corners the full length of the box height.

what you show is a floating tenon.

 

these are what i consider splines:

 

both vertical and horizontal in the corners.  adds some strength and some accent to a weak joint.

I don't use them often because a side-grain to side-grain glued joint is stronger than the surrounding wood.  If you are going to do any distance like the drawing shown by Stick, you would be wise to segment the spline as you have cross-grain construction.

 

In a way, biscuits are splines (or maybe you can consider them floating tenons), but I only use them in butt and miter joints. 

 

I do often add contrasting keyed splines in the corners of mitered boxes.

I have seen "splines" in Sticks example in a couple of wood working plans and the plans referred to them as Splines, not floating tenons. I think a floating tenon is bound on all 6 sides/ends, OR it can be just a matter of semantics.

In the plans I have seen them in use (similar to Stick's example) they were for helping to attach solid wood banding to a desk top.

On a glue joint as shown in the example I always glue the edges together without any mechanical help.

It would seem that a "Spline" of this sort would be more for alignment than strength.

Have not used as you've shown. As Keith noted, I've used biscuits in a similar fashion but more as alignment. I'm not sure of the advantage if edge glued unless you were not edge gluing to allow for expansion/ contraction such as a solid wood back or bottom. 

Back in the "old  days" when I worked in millwork shops we joined many panels together using spline joints as Stick shows, It  was just called a spline joint. The groove was made with a 1/4" bearing guided router bit and the splines were made from 1/4" 3 ply fir plywood that was actually 1/4". Try and find that today. It made a strong joint and with good alignment.

Well, one could even shape the spline to look like a dovetail's pin  and show it out both sides of a corner...

I have used splines in picture frame corners. I glue the frames up in corner frames, put them on a gig I made for the table saw and cut each corner. Place splines in and glue. I especially like to use them when I make frames out of distressed or weathered boards. It makes them as strong as the can be

I've used them several times, but in a side to side use it was always hardwood edging om a plywood field.I've done quite a few like the ones Bill and Keith showed (on mitered edges) but I've never heard them called floating tenons. Seems like once or twice the spline material I used was 1/4" hardboard. I built a Wood mag plan for a sewing cabinet and they called for it; this was some years ago and I blindly followed their guidance. Turned out there wasn't any failure with the joint, but I still wonder about the wisdom of using the stuff (hardboard).

55 minutes ago, Fred W. Hargis, Jr said:

I've used them several times, but in a side to side use it was always hardwood edging om a plywood field.I've done quite a few like the ones Bill and Keith showed (on mitered edges) but I've never heard them called floating tenons. Seems like once or twice the spline material I used was 1/4" hardboard. I built a Wood mag plan for a sewing cabinet and they called for it; this was some years ago and I blindly followed their guidance. Turned out there wasn't any failure with the joint, but I still wonder about the wisdom of using the stuff (hardboard).

think about it...

A long floating STUB tenon...

I'd wonder about hardboard too...

FWIW... the more plies the merrier plywood works well for the splines...

Edited September 15, 20169 yr by Stick486

from another forum...

 

A spline is a continuous floating tongue in a tongue and double groove joint.
Biscuits are interrupted splines in double interrupted grooves.

Both are versions of a mortise and tenon joint, the mortise and tenon being typically much longer and deeper.

The strength of all 3 is that the wooden spline/biscuit/tenon provides a strong mechanical barrier to vertical shear forces as those forces have to shear the wood and the glue, In a butt joint the glue would have 2 planes of shear failure, both horizontally and vertically. Biscuit/spline/mortise joints have mostly only one shear plane which is parallel to the face of the biscuit/spline/tenon or horizontal shear. Obviously, the longer this plane is, the greater the resistance to shear failure. That's the engineering explanation.