Fixing solid table tops to frames with glue?

[Mike-W]

I am making a small occasional table, the top is made from two pieces of Olive Ash joined down the length, the overall size of the top is 1000mm x 400mm x 22mm thick. The top sits on a pair of 'picture frame' legs with a rail running between the two end frames. There is only one rail at the back as I need to be able to slide two smaller tables in from the front under this table, giving me a nest of tables.
The end frame legs will be fixed to the underside of the top at either end solid Ash top running across the width of the tabletop.
I know the normal method of fixing solid tops to frames is to use buttons to allow for movement in the wood across the width of the timber, however I cannot use buttons because I need to slide smaller tables underneath the main table, I have set a tongue in the top of each rail and would like to glue this into a grove on the underside of the top. Given the length of the tongue (about 300mm) am I likely to run into long term problems with movement in the top, might I be better off using a flexible PVA type glue? Can anyone make any suggestions before I go ahead & glue this up?
Mike-W

 

[DaveL]

Mike,

How big is the rail timber? How about using screws with holes counter bored on the top side of the rail. The idea is that the screw flexes in the counter bore allow the top some movement. I have seen it somewhere on the net but have no idea where. ](*,)

 

[Mike-W]

The rail running between the two end frames is not in contact with the top as it is set about 300mm from the base of the frames (frame height 400mm) the rails are 48mm by 17 mm, rounded over for decorative effect so I don’t want to run any screws through the frame itself up into the underside of the top.

Mike-W

 

[SlimShavings]

HOw bout short sliding dovetails. Cut 4 double dovetail (pins (X)) about two inches long (or whatever). Rout a dovetail (tail)2in long (or what ever)in the top of the legs from the back and a slot and dovetail (tail) in the top. It would be a loose tenon thing and kinda like hanging a picture frame on a screw. you can glue the pins in the legs and one set of pins in the top allowing the top to move. As long as you don't rout clear through the legs no one will see them Don't know if this description makes any sense or not "Murican" explanation

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THis ain't postin like in the editor . Have to move the bottom half to the left so it looks like a doulbe dovetail #-o ](*,)

 

[Chris Knight]

If the ash is quartersawn, you might get away with gluing in a table of that size. However, I would use a fastener that allows some movement. They aren't the prettiest of things but two kinds of metal fastener would let you fix th top and allow for movement. They are the "Z" shaped fasteners that engage a groove in the rails and the figure of eight fasteners that can swivel to accommodate movement.

These fasteners would not be seen unless you bent down to look and they would both allow room for a nesting table underneath (especially the figure of eights which is what I would use given the way I envisage the table's construction - which suggests that for rigidity, it would be useful to have a ppositive a fixing to the top as possible?)

 

[jasonB]

Do the two picture frame legs come into contact with the top?. if so use the screw and elongated slot method through these.

Jason

 

[Mike-W]

Thanks to every one for the advice, I think I will either use 4 small brass plates with slotted screw hole's or route 4 Keyhole slot's into the underside of the table top & run round head's into the top of the frame. Using glue may not be worth the trouble!
Mike-W

 

[jonny boy]

HI,

Can you use some small stretcher plates by firstly routing a small recess for them to sit flush, (just like a door hinge sits flush) you would have to bend down to see them.

cheers, jonny.

 

[Alf]

figure of eight fasteners that can swivel to accommodate movement.

Okay, I confess I'm feeling too lazy to go and look*; is there a UK supplier of these?

Cheers, Alf

*Aww c'mon, I'm owed one or two aren't I?

 

[Chris Knight]

Alf,
Dunno offhand, I have had a few for years but can't remember where they came from. Rockler have both types - http://www.rockler.com/findit.cfm?cookietest=1&page=786