Attaching to end grain

[dicktimber]

While I have made boards by biscuit jointing and glueing, I was wondering how the mechanical properties would be, doing the same thing on end grain.?
I don't have any project going at the moment but was wondering if I edged a small table top all the way round say in a different type of wood for aesthetics, would I loose any joining properties on the end grain edges.......or is this a definite no no.?
Mike

 

[Chris Knight]

Mike,
You could treat the ends as "breadboards" for the joinery and to overcome end grain gluing issues but you will still need to design in allowance for the widthwise expansion of a solid wood top if that is what you plan on using - as I infer.

One way this might be accomplished would be by leaving a small gap for expansion of a few mm and treating the edging as a T&G but only gluing the end edgings in their centre portions for example.

Far easier to use a veneered MDF centre section!

 

[dicktimber]

Chris
I googled it just after I posted and didn't realise papers had been written on the subject, full of mechanical testing using PVA glues etc.
The last time I edged anything I used veneered MDF for the main surface, and solid edging,so it wasn't a problem.
I will either go down your route and do a sample, or revert back to a veneered board...in the long run I think this would probably be the safest option.
Thanks for the help

mike

 

[dicktimber]

Just watched Paul Bradburn...and I have to say I rate him and his cutting edge prog.

He made a CD cabinet. The top was maple with walnut sandwiched strips to give a solid banding.
He then used biscuits and glue to edge the top in the end grain.

He went on to say that by doing this it helped stabilize the top and prevent bowing, which to me did sound logical.
I am now confused as by doing this it seems pointless making elongated holes in the top attachment brackets, because the whole top is prevented from expanding and contracting.

 

[Chris Knight]

I haven't seen the program but if as I understand, in essence, he glued a breadboard end to the top?

If the top were more than say 8 inches wide, there will be trouble when the humidity changes much and the top expands or contracts.

 

[dicktimber]

Chris
I agree and is against everything I was taught.

But he isn't a stupid bloke and must think it is a reliable option?

 

[JoinerySolutions]

A CD rack is generally not much larger than the CD itself, so if he was using PVA to glue up then the chances are that there is sufficient 'creep'
in the glue to allow for expansion and contraction.
This 'creep' is sometimes seen when glued up boards that have been sanded dry out a little more and there is a ridge of glue all along the glue line. The wood is allowed to move slightly but the glue appears to stay in place. :duno: why!

 

[dicktimber]

Joinery solutions

The problem is this was a cabinet top..not a CD racking system.
The CD were stored in 4 drawers.