Do you dry the ribs, along with the board, prior to gluing ?

[Prof. Euphonious Thump]

     This is fun !!! This is a  suggestion I made
years ago, on this list, and was roundly "poo-pooed" (
as usual ) if I remember correctly.
    So, then, who's refined this technique and put it
into practice, and where can I read about their
discoveries ??? And should I use sugar pine, spruce,
maple or what for the added lamination ? And what kind
of glue ?
 ( I was thinking epoxy would have minimal creep, but
then, if the rib and addition were dowelled together (
maybe with bamboo skewers ) the couldn't "skid" over
each other, at all. 

Thump


P.S. This 57" Ivers and Pond upright has very wide
ribs,  with nearly flat tops and a lot of room behind
the posts, so it's tempting ! 





--- Richard Brekne <ricb at pianostemmer.no> wrote:

> 
> Rib extenders are simply additions to the height of
> the existing ribs.  
> They can be made with some degree of machined crown
> so that when glued 
> they exert an upwards force on the existing
> assembly.  One can also put 
> them in a high humidity hotbox and glue them on in a
> state of very high 
> MC so as to attempt to take advantage of  their
> shrinkage as they loose 
> MC... kind of the reverse of gluing a dried panel on
> the board.  That 
> last came to me from Ron Overs recently.  I suppose
> you could press the 
> assembly upwards as well and glue on extenders match
> the surface of the 
> existing ribs... also a way of increasing crown.
> 
> The point with extenders as I understand it is that
> they increase 
> existing rib height... which does a lot more for
> stiffness without 
> adding as much mass as adding extra ribs will.  Of
> course you have to 
> have room to place them... and if you are dealing
> with very high ribs to 
> begin with then perhaps this is not such a good
> idea.  But for shallow 
> and wide ribs that have lost their gumption....
> seems like a good idea.
> 
> Cheers
> RicB
> 
>     "Rib Extenders "??? What's that ???  This one
> has wide, flat topped
>     ribs,. so I thought I might laminate something (
> suggestions as per
>     materials appreciated ) to their tops, if I'm
> not happy with the
>     crown I get.  I'll tell you all about this
> recrowning method when
>     I'm done, and have more to report per results.
> 
>         Peace,
>          Thump
> 
> 
> 



      ____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page. 
http://www.yahoo.com/r/hs