GGs,

I'm planning on building a few torsion boxes for shelving.  They will be
just longer that 6 feet.  My quandry is how many clamps I need to glue the 1
ft x 6 ft quarter inch plywood to the torsion box frame.  My golden rule of
clamping always seems to be that for any clamping job I need at least one
more clamp than I have ;-) but there must be a better way to estimate
clamping needs.

If I know the gluing surface area, is there a numerical estimate of how much
force (in pounds I guess) I need to apply? How much force does a really
tight Pony clamp exert?

Thanks

Jonathan Lee

Johnathan,
  If you have a flat surface as in a cement slab or something, use water. You
don't need a clamp one. Assemble trash cans, big buckets, or whatever and some
padding scraps, maybe 3/4 ply. Glue on your panel, pad with the scraps, top wit
h
the containers and bring on the garden hose. Leave the hose in the last one whe
n
you shut off the water. When the glue is done just unscrew the hose and it will
siphon itself back out. Just before the first container empties plug the hose
with your thumb and put in the next. The siphon will continue.
    Works for me and the price is right.
   Say, I think I just told this tale last month. Sounds familiar to me.
     yours,  Scott
*******************************
   Scott Grandstaff
   Box 409 Happy Camp, Ca  96039
   scottg@s...
   http://www.snowcrest.net/kitty/hpages/index.html

"Lee, Jonathan" <Jonathan.Lee@h...> said:

> I'm planning on building a few torsion boxes for shelving.  They will be
> just longer that 6 feet.  My quandry is how many clamps I need to glue the 1
> ft x 6 ft quarter inch plywood to the torsion box frame.  My golden rule of
> clamping always seems to be that for any clamping job I need at least one
> more clamp than I have ;-) but there must be a better way to estimate
> clamping needs.
>
> If I know the gluing surface area, is there a numerical estimate of how much
> force (in pounds I guess) I need to apply? How much force does a really
> tight Pony clamp exert?

Jonathan, you don't need to worry about the amount of force, you need to
worry about how it's spread.  You can think of each clamp's force spreading
at 45 degree angles from the clamp head.   The farther the clamp head is from
the glue line, the wider the area of coverage of that clamp.  This is one of
the reason that clamping cauls are used.

Stack some wood on top of the 1/4 inch plywood before clamping, and you'll
greatly cut down on the number of clamps needed.

-----------------------------
Hal Laurent, Baltimore MD, US
laurent@c...

Jonathan Lee pondered from the far end of the porch:

>I'm planning on building a few torsion boxes for shelving.  They will be
>just longer that 6 feet.  My quandry is how many clamps I need to glue the 1
>ft x 6 ft quarter inch plywood to the torsion box frame.

Take a hint from the cedar strip canoe and aircraft rib builders.  Get a
stapler and wack it together.  Pull the staples out after the glue dries.
That little gem does assume that you can live with the dots that will
be left by the staple holes.  When I did the canoe I shot the staples
through cardboard to make it easier to pull them back out.  Glossy
wine box cardboard worked best :-).  Other options for pulling are the
plastic that holds six packs of Coke together and the string that Home
Despot passes out for tying down loads.

>If I know the gluing surface area, is there a numerical estimate of how much
>force (in pounds I guess) I need to apply? How much force does a really
>tight Pony clamp exert?

A whole lot less than you need.  SWMBO vacuum bags her marquetry.  An
auto vac pump and thick poly sealed with plumber's putty does the
trick there.  No staple holes but a little more expense.  Be careful
that you done crush things.

Dave
Retsof, NY is downright cold tonight!!!