my own Soundboard

[Greg Newell]

Ron,
    A great deal of help! Thank you!! If you think of more I'm all ears (or
eyes in this case).

Greg

Ron Nossaman wrote:

> Hi Greg,
>
> There are a lot of different approaches and tooling preferences. I'll give
> you mine.
>
> I haven't assembled my own panels because I have neither the shop space for
> thicknessing machinery, which in my case would probably have to be a stroke
> sander, nor the volume requirement to change that. While I have sent a few
> panels back to suppliers when they didn't remotely resemble what I had
> requested, it has for the most part been an acceptable means of getting a
> panel. Would I prefer to build my own? Sure.
>
> Crowning ribs is a matter of deciding what you want in a crown radius (or
> crown radii) and coming up with a jig and tooling to produce it (them) in
> the ribs. There are as many ways to do this as there are soundboard
> installers. Your first idea will probably work. Your second idea will
> probably work better.
>
> For gluing ribs to panels, I like pneumatic clamps similar to those shown
> in Claire Davies' PTJ article. I like pneumatic because I can feather the
> ribs quickly and easily with a jig and router setup before gluing them on
> and still get uniform clamp pressure on the joint without having to mess
> with spacers and cauls. I use five clamps. Mine are made of maple, to keep
> caul flex to a minimum, with a different radius curve cut into each. The
> radii get tighter toward the treble. I don't mount them on a frame of any
> sort, and just move them from rib to rib as I work. No, it's not necessary
> to keep everything "level" as you go. The board doesn't care and will
> accommodate when it's glued in. With the panel dried to 6%MC, using
> Titebond, by the time I get five ribs glued on, the first clamp can be
> taken off and moved to the next rib. I'll usually give them a little longer
> though, for insurance. I've been running the air pressure to the clamps at
> 40 PSI with no problems.
>
> For gluing the finished board in, I like regular old F clamps and wooden
> spacer blocks. The clamps are available commercially without having to make
> them, and they are a general use clamp, rather than specifically dedicated,
> which come in handy for plenty of other uses around the shop. I have a
> couple of dozen 4.5"x24" I got from New Mexico Woodworking (I think),
> because I couldn't find available Besseys in that size at the time, and a
> dozen 2.5"x18" Besseys for the belly rail and less ambitious general
> purpose around the shop clamping. Jorgenson, Record, and Stabil make pretty
> first rate F clamps too. For clamping the panel to a cutoff bar, I use go
> bars made from old maple flooring. Very low tech, and very effective. I
> make a perimeter caul out of cheap 3/4" plywood, the width of the inner
> rim, to help distribute the clamp load evenly on the panel and keep the
> spacer blocks from denting the surface.
>
> Dry fit the assembly in the rim, trimming ribs as necessary to make sure
> everything fits to your satisfaction (including a dry run with clamps)
> before gluing. Here's where you locate and install the bridge too. Clamping
> the board in, or temporarily screwing it down, you either locate the bridge
> from a pattern made before teardown (if you want the bridge back where it
> originally was), or you can lay the bridge on the soundboard, drop in the
> plate, and locate both where you want them at the same time. Hint: you
> can't slide the bridge in under the plate once it is down, so don't forget
> to lay it on the board first. Another hint: you will probably eventually
> verify this for yourself. Mark the bridge position on the board, pull the
> plate, remove the board, glue and screw the bridge to the board, and you're
> ready to install it.
>
> Do a full dry run installation or two with a helper so everyone knows what
> to do when and work out the choreography so you're not gluing and clamping
> one another instead of the board. With your board at whatever your working
> %MC was when you glued on the ribs, quickly apply plenty of glue to the
> inner rim and belly rail, lay in the board, lay on the perimeter caul(s),
> set in spacer blocks and clamp as you go. I like to start clamping at the
> right front and left rear, because these areas will have to be pushed down
> farthest to meet the rim and this will tend to press the rest of the board
> perimeter into wet glue as soon as possible.
>
> Don't try to crush the piano with the clamps, and don't forget to mop up
> the squeeze out while it's still wet.
>
> Oh yes. Now that you have the board glued in - it's easier to finish the
> bottom before you do that than after it's installed. Just keep the finish
> off of the gluing surface, as you already know.
>
> That's probably not everything, but it's a start. I hope it's of some help.
>
> Ron N

--
Greg Newell
mailto:gnewell@ameritech.net