coffee table with mitred corners

[EMistral]

Hi all,

As mentioned in an early post, I am making a coffee table.
The top is roughly 1m long by 50cm wide
The inlay is of mixed victoria ash and sassafras and will be around 92cm x 43cm
It will be surrounded by a jarrah border with mitred corners
Now I know that the inlay will expand and this will cause the mitres to split.
I had a look on the forum for similar problems some members have encountered but it seems that the advices they were given was either to remove the edging and use breadboard technics or use a combination of MDF+veneer for the inlay
Well I will definately not go for the veneer solution since I don't like veneer and can not stand MDF for furnitures so I was wondering if you guys had a solution to allow for the wood movement and still using a mitred corners solution for edging
any advices or solutions are more than welcomed
Thanks
Eric

[Rocker]

Eric,

I suggest that you make the solid-wood central part as a floating panel with a tongue that engages with a groove in the centre of the inner edges of the edging. You probably need to allow for a total of about 5 mm of possible expansion across the grain.

Rocker

[EMistral]

Thanks Rocker

Pardon my ignorance or if the question seems stupid but in what this will prevent the mitred corners to split?
If there is a tight fit between the central part and the edges even with the groove, the central part will expand and this will cause the corners to split.
Unless I have missed something along the way!
probably in a more "free" way since it is not glued
My initial idea was to rebate a 1cmx1cm groove on the inner side of the edges (a bit like the back of the picture frame to hold the glass) and then do the same on the central part and just install it on the top
But in that case I need something to secure the central part to the edge
something like the 8 clip for fixing table tops
But after thinking, I don't see how this could prevent the mitred corners from splitting

[soundman]

AAAH
the centre part isn't a tight fit in the mitred frame...

and yess some sort of groove feature would be a necessity to make the joint look right under all conditions.
Something in the size of a saw cut or perhaps a cork inlay.

cheers

[Rocker]

Eric,

A mentioned in my earlier post, the panel should have sufficient gaps on either side to accommodate wood movement, and the tongue should not be glued in its groove. You will only need a minimal gap at the ends of the panel, since it will not expand in that direction.

Rocker

[EMistral]

Hi Rocker,

That's the type of join I was thinking but leaving a gap is not that nice
how wide should the gap be ?
1 or 2 mm?

[Rocker]

EMistral,

I think 2 mm on either side of the panel would be enough; I don't think the gap would look bad. But anyway, it is essential to have a gap, unless you use veneered MDF or veneered plywood for the panel.

Rocker

[Gumby]

unless you use veneered MDF or veneered plywood for the panel.

Rocker

As much as you might not like it Eric, that's the best solution in my view

[Lignum]

Eric, if your using a mix of Ash and Sas as a panell, depending on how many and the widths of them, it should be a stable top. And if that panell is 450 wide then you will glue and screw in the middle 1/3 into the frame and that leaves two 150mm sides that will do all the moving. A 2mm gap like Rocker said will be all thats needed, and if you have the same gap top and bottom as well it will look very neat and you will have no trouble with the miters splitting:)

[EMistral]

Thanks all

It is true that 2mm might not be too bad.
I might try this solution or go for the breadboard which might also look neater since it will be a contrast between Ash+Sassafras centre top and jarrah breadboard
I'll post some pictures when it is finished

[Wood Butcher]

I would go for the breadboard ends in preference to a 2mm gap in a coffee table. I wouldn't like to have gaps that stuff could fall into and would be a bugger to get out.