Flat Belly Rail

[Farrell]

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Ron O wrote:=20
> I pulled one original board which=20
> clearly had lots of crown when it was installed, but the inner was=20
> made flat. The glue joint was good around the outer edge but the=20
> inner edge was only just making contact or just off the rim.

Sound to me like somebody needs to learn how to either spread glue, or =
more likely clamp a glue joint thoroughly!

I've started to use a method that Ron N shared with me. I cut strips of =
scrap plywood the shape and width of the inner =
rim/belly-rail/fish/cut-offs/etc., place them on top of the soundboard =
and use those pieces as clamping blocks. I think use of such blocks, =
along with numerous clamps, insures a pretty darn good glue joint - oh, =
and good glue surfaces and good glue and the proper amount of glue and =
anything else I have neglected to mention.

Terry Farrell

----- Original Message -----=20
> >Is a flat belly rail a good idea then?
>>
>>Thanks
>>RicB
>=20
> It is around here. We're using a flat belly rail in our 225 pianos.=20
> By this I mean that there is no curvature across the span of the=20
> belly rail. The central area of our boards have nearly 10 mm of crown=20
> unstrung. When strung, a string line placed underneath the board will=20
> almost clear the sound board buttons. If the belly rail was crowned=20
> as well it would make for serious problems achieving a workable=20
> relationship between bridge height, bearing block height and the=20
> correct down bearing angle setting.
>=20
> We do angle the belly rail and inner rim gluing face to the crown of=20
> the board. As Terry suggests, it probably isn't greatly important.=20
> But I like to do it just to know that the glue joint is good all the=20
> way across the interface. I'll pulled one original board which=20
> clearly had lots of crown when it was installed, but the inner was=20
> made flat. The glue joint was good around the outer edge but the=20
> inner edge was only just making contact or just off the rim. I can't=20
> say I'd be comfortable about such a gluing arrangement. It could very=20
> easily allow noise at the perimeter of the board in some instances.
>=20
> Ron O.
> --=20
> OVERS PIANOS - SYDNEY
>    Grand Piano Manufacturers
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