"henny" wrote in message
...
I bought a pack of figure 8 table top fasteners for my mission style
coffee table. I needs some tips.

My table is roughly 22" X 48". Should I use 3 fasteners for each rail
and 1 for the middle of each stretcher? The fasteners are about 1/2"
in one end of the figure 8 and 5/8" at the other end.. Which is the
optimal end to be on top of the rail and stretcher vs. the table top.
(ie the 1/2" end or the 5/8" end).

I realize the fasteners on the rail end can pivot slighty but what
about the stretcher ? If I mount them perpendicular to the stretcher
they can't pivot it the table top expand. Should I mount them at a 45
degree angle on the stretchers or should I even skip mounting them on
the stretchers?

Lastly should I mount them so they face inward or outward from the
rail and stretcher.

(P.S. a forstner bit seems optimal to embed them in the rails and
stretchers.)

Those figure eights work fine for holding across the grain while allowing
some swing either side to accommodate wood movement. I wouldn't use them on
the long grain unless they were out of line, as the ones Clarke recalls,
with clearance for them to swing into the apron area.

The best for the long grain, which does not move significantly, are these
http://www.rockler.com/findit.cfm?page=784 which require a groove. Since
your wood will be pretty dry during heating season relative to summer
conditions, unless, of course you use air conditioning to cool and dry
things, you' want to keep the end a quarter or so off the bottom of the
groove to allow expansion. If you're year-round drying, perhaps half that.
You can get a bit more precise by looking at your species and grain
orientation and then at the fpl _Wood Handbook_ for shrinkage figures.

For example, you say Mission, so let's presume white oak, which shrinks
tangentially about 9% of width from 30% to 0% moisture content. Means a
safe figure is 3% of width between fasteners, since it's pretty linear. 22"
yields about 5/8" for a 10% annual swing. My house. Winter is as low as 5,
summer approaches 15%. You can game your actual wood and conditions a bit if
you must.

Three along the long rails, two on the short should be a good mix. Be sure
to apply coats to both sides of the tabletop to keep things even in the
moisture uptake department, saving yourself the lift at the edges of the
table.

The best for the long grain, which does not move significantly, are these
http://www.rockler.com/findit.cfm?page=784 which require a groove. Since
your wood will be pretty dry during heating season relative to summer
conditions, unless, of course you use air conditioning to cool and dry
things, you' want to keep the end a quarter or so off the bottom of the
groove to allow expansion. If you're year-round drying, perhaps half
that. You can get a bit more precise by looking at your species and grain
orientation and then at the fpl _Wood Handbook_ for shrinkage figures.

Z clips are also best for crossgrain.
Either way, you want to screw the top down in the middle of the crossgrain.