Gluing Rawhide and Veneer to
Self Bows, Part II, Continued
By Dean Torges
Mist the rawhide on both sides with a squirt spray bottle.
Don't soak it. If you don't have a spray bottle, dip the rawhide
in the reservoir of warm water and squeeze off excess moisture
between your thumb and forefinger. In either event, set the rawhide
aside to relax while you spread glue over one limb.
When the rawhide has become supple, spread a layer of glue over
the flesh side. Notice the affinity of glue and hide. Resin glues
(Titebond white and yellow and Type 11) act like oil on water
at this stage. Give things several minutes to chill off while
you recheck the iron temperature and hone your pocket knife/trim
tool.
Starting at the handle, position the rawhide the length of the
limb and iron down the first 5 to 6 inches. You've already glued
glue to rawhide and glue to wood; now you are gluing glue to
glue. Don't let the rawhide dry out and don't let the iron get
too hot.
As soon as you have re-melted this section of glue, exchange
the iron for the hammer. It functions to squeegee any air and
all excess glue from between the rawhide and the bow back while
making good advantage of the natural suck of hide glue. The glue
hereby becomes its own internal clamp.
Thoughtful tool manipulation will assure you of a good bond.
Wiggle the tool handle back and fort has you simultaneously sweep
the tool in a gentle arc from the center toward each edge in
turn, lapping each sweep like fish scales. Work from the handle
to the tip. Remember, the object is to move air bubbles and excess
glue ahead and off to each side, not back and forth and up and
down.
Keep the rawhide moistened and the hammer warm. Don't worry if
glue slops on top of the rawhide. It serves to lubricate the
metal blade and has no adverse effect on the finish. Indeed,
glue purposefully dabbed atop stubborn or rough areas 1 Lubricates
the hammer and helps coax them into place. After one section
is down, move ahead with the iron to the next section. (Don't
forget to place the hammer back in the hot water bath.) There's
no need to hurry. Only with hide glue can work speed be determined
by your own individual comfort level rather than by glue constraints.
You can't mess up if you pay attention. If you overwork an area
and suspect you've starved the bond of glue, lift up the rawhide
and take a peek. Wipe down a little more glue, reposition the
rawhide and make the necessary adjustments in iron heat or tool
pressure and manipulation (hammering).Familiarity with the process
produces a straight-ahead job in short order. After a bow or
two you won't feel the need to backtrack and the work will move
quickly.
You should end up with a uniform amount of glue squeeze under
the rawhide overhang down both sides of the limb as clues to
a good job. If you don't, moisten the area, reapply the iron
and squeegee the doubtful section over again.
When you've finished one limb, run a sharp blade down each side
to trim off excess glue and rawhide while they are still soft,
being careful that the slanted blade pressures the rawhide down
against the bond (as opposed to pulling it away). Don't worry
about the rawhide shrinking back from the edge with further drying.
It won't because it never bloated in a soak. Besides, it is now
glued down too tightly.
One of the advantages of this method over any other is that the
process allows you to constantly monitor the results. If you
see trouble, you can rework areas until you are pleased with
the bond. No guesswork.
No great long setup time, either. YOU can begin final trim and
cleanup within several hours. When the excess glue becomes gelatinous,
it peels off readily. By then the rawhide will be dry enough
to file or sand. Either with a second cut file or a large mill
bastard, maintain one angle along the edge of the rawhide and,
without removing wood, feather it into the bow's radiused edges
for a neat and uniform trim.With warm dry weather or temperate
use of your heat box, you can tiller and string, up within 36
hours.
After the rawhide is quite dry, usually within 12 hours,
run your fingers over it lightly with your ears close by. If
you find an area that "whispers" as your fingers travel
back and forth, the bond there is unsatisfactory. Heat up the
iron, moisten the area, revitalize the glue with the iron and
work the bubble down with the hammer or the roller. It'll fix.
You may wish to add two auxiliary tools. One can be had by modifying
a wallpaper seam roller.Simply replace its wooden wheel for one
of solid brass or copper, and use this tool as you do the veneer
hammer. You may come to prefer it over the veneer hammer for
working edges or for lumpy areas such as knot clusters. Keep
it hot in the water bath, too.
The other is the serrated plane blade used in toothing planes.
You'll need one when we get around to building a toothing plane,
which I find indispensable for thicknessing components and preparing
glue surfaces for composite bows. For now, the blade itself handheld
and dragged across the bow's back prior to spreading glue creates
an ideal glue surface. The tiny troughs which result greatly
reduce the risk of starving the bond between rawhide and wood,
and a starved glue joint is probably the only worry that need
concern you through the hammering process.
Rawhide sucks moisture like a sponge. To maintain the bond, apply
a good finish (see TBM SelfBow column, Jun/Jul 97). Even a Titebond
II bond requires protection. It is water resistant, not waterproof.
If you need a demonstration of the difference, leave an application
brush into which it has dried thoroughly in an overnight water
bath.
This process yields smooth and uniform results. There is no need
to have a hide-bound bow marred by the tracks of string wraps
and tie-downs or peeling loose in places like a reptile in slough.
You may have to live with many kinds of mistakes, but you don't
have to shoot with them.
In the next and final installment of this process, we will look
at using this technique for applying inexpensive furniture grade
hickory veneers to bow limbs for advantages beyond those provided
by rawhide.
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Source of Supply: Cabinet
makers' veneer hammers and toothing plane blades can be purchased
mail order from The Garret Wade Tool Company. Phone (800) 221-2942.