Short version: size both sides of the board with VERY thin hot hide
glue. By very thin, I mean the stuff should look and feel just like weak
tea, save that it won't be perfectly clear. Hot dirty water, sort of.
You'll have a strong enough mix if the stuff left on your fingers begins
to feel ever the slightest bit sticky after a minute or so of cooling
and evaporation.

Flood it on one side of the board and watch in horror as the thing curls
up like a cinnamon stick. When it's dry, the board will flatten back out
somewhat (maybe overnight), but still be a bit humped. Now do the other
side, and go through the same thing in the opposite direction. Now let
the thing stabilize for a day or so, and eventually it will lie flat
enough (perfectly flat isn't important). The surface will have a
slightly rough "feel" to it, but will have a nice shine, and things will
glue to it much more effectively. This treatment seems to boost the
acoustical sensitivity of the thing, though you won't really get the
full acoustical "hit" until the edges are locked/glued into the case. It
will make gluing more effective because the glue won't soak into the
wood as far and 'starve' the joints. But you will have to use
proper-strength real hot hide glue for gluing on the bridge and ribs.

As for a final coat of something-or-other, we all have our disagreements
and crochets. I don't use shellac, because to me it sounds hard-edged
and "plastic-like," (it is, in fact, a natural polyester!), but if the
shellac final coat (AFTER any gluing is done, PLEASE!) is extremely,
vanishingly dilute, it will probably do nothing noticeable. I use myhrr,
but only because it has a nice texture, smells nice, and gives me the
illusion of at worst not hurting the sound. But I have also just left
the board with nothing more than the glue size without any problems (the
new Italian didn't develop any stickiness on the board in the
near-100%-humidity extreme heat in Boston).

owen



"Timothy S. Hall" wrote:
>
> I am happy to report that my little Cembalino is progressing nicely, with
> the case sides and liners in place.  I am currently dehumidifying the
> basement workshop to about 36-38% in preparation for the soundboard work -
> the case went together at about 44%,  This is what our house usually reads
> on the cheap Radio Shack meter.  I am taking pictures as I go, and will put
> them up as soon as I figure out how to do it on our new DSL account. (I will
> *never* go back to dial-up 56K service at home!)
>
> Now that I'm ready for soundboard work, two questions:  I remember
> discussions in the past about sizing the soundboard with thinned hide glue
> (or shellac?)  to improve tone & response - could anyone point me to those
> discussions in the archives ("soundboard sizing" returns no hits) or recap
> the salient points?  Why does this work, and what's the best material to
> use?  Second, this instrument has no rose in the soundboard, but aren't
> roses common in Italianate instruments?  What aspects of the design are
> affected by the presence of a rose, and would it be a fool's errand to try
> to put one into an instrument not designed for it?  I'm remembering and
> coveting those gorgeous custom Italian roses that someone provided a link to
> a few weeks ago.
>
> Thanks as always,
>
> Tim
> [log in to unmask]

--
"The music business is a cruel and shallow money trench, a long plastic
hallway where thieves and pimps run free, and good men die like dogs.
There's also a negative side."
--Hunter S. Thompson