Epoxy Reinforcing of Action Parts

[gordon stelter]

I think that I would try reinforcing them by dunking
in some super-thin CA, then redrilling where needed.
CA is more likely to permeate this tiny, dense stuff,
methinks, and without getting all "syruppy".
     T

--- Dave Nereson <dnereson@dim.com> wrote:
> 
>   ----- Original Message ----- 
>   From: Farrell 
>   To: Pianotech 
>   Sent: Saturday, March 29, 2003 2:10 AM
>   Subject: Re: Epoxy Reinforcing of Action Parts
> 
> 
>   A man after my epoxy reinforced heart! Please
> explain the items below:
>     
>   ----- Original Message ----- 
>   From: "Bill Ballard" <yardbird@vermontel.net>
>   To: <pianotech@ptg.org>
>   Sent: Saturday, March 29, 2003 12:03 AM
>   Subject: Epoxy Reinforcing of Action Parts
> 
> 
>   > Dear List,
>   > 
>   > i'm working on a 1906 Krakauer 5'10" grand,
> restringing with original 
>   > board and block, new shanks and hammers, and
> lots of 
>   > refurbish-whatevering in the action. New shanks
> were a must because 
>   > the wood was fracturing right at the bushings
> (must be reed maple, or 
>   > a let-off rail problem. But I stayed with the
> original reps.
>   > 
>   > It turns out all action parts or what looks like
> American Beech, 
>   > which after nearly 100 years is quite brittle.
> (That's why the 
>   > fractured shanks.) The reps did better, although
> the week spot is the 
>   > joint between the jack fly and tender.
> 
>   What is the "jack fly"? I imagine the "tender" is
> the foot part?
> 
>   You didn't ask me, but I think I can answer a lot
> of these -- "Fly" is a factory term for the jack. 
> Yes, the tender is the part that hits the regulating
> button.  
> 
>   > I fond out quickly that I 
>   > wasn't going to be able to cradle the jacks the
> usual was. 
> 
>   Please explain "cradle the jacks" - I am not
> familiar with this term.
> 
>   I think he's referring to centering the jacks in
> the repetition lever windows (by supporting the
> wippen from underneath the jack center pin "fork" on
> the side towards which you want to move the jack,
> and tapping the top of the jack with a small hammer
> to bend the center pin).  
> 
>   > The back 
>   > of the jacks shear off through the CP hole. 
> 
>   Can you clarify this at all - can't quite picture?
>  
> 
>   But the old wood is too brittle, so instead of the
> pin bending, the jack just splits and shears off at
> the center pin hole.  
> 
>   > Bending the pin and 
>   > rotating it to vertical isn't going to work.
> (The bent pin puts a 
>   > gouging stress on the bushing, and shows no sign
> of ever loosening to 
>   > proper friction. Also the orientation of the pin
> appears not to be 
>   > stable.)
> 
>   Again, please explain/clarify. Why are you bending
> pins? What pin - center pin? Rotating to vertical? I
> don't have a clue as to what you are describing.
>   Bending pins to center the jack in the rep. lever
> hole (other alternatives are  to install a new jack
> and hope it's straight, or plug the center pin hole
> with ??? and re-drill it, which I've never tried. 
> Or put in a whole new wippen).  Yes, center pin.  By
> vertical, I think he means centered in the window,
> as opposed to the jack rubbing on the wippen because
> of a jack center pin hole drilled crooked (or jack
> warpage, or sloppy bushing).
> 
>    
>   > But there are jacks which will need cradle, and
> no matter how low I 
>   > set the psi on the air nailer, the jacks
> fracture when I tap them to 
>   > cradle them. 
> 
>   Air nailer? To "cradle" a jack? What is this
> process? Please describe in detail.
> 
>   Never heard the term, but imagine that "cradling"
> is centering the jacks in the window.  The tops of
> the jacks are given a light but firm tap with a
> small hammer, just enough to bend the pin and make
> the jack move laterally maybe 1/64 or 1/32, 1/16
> max.  "Air nailer" is a bit of humor.  
> 
>   > So my next best guess is to impregnate the beech
> at the 
>   > jack's elbow. That should render the jacks
> strong enough to take a 
>   > cradling tap.
> 
>   You can put epoxy between wooden parts. You can
> add epoxy to the exterior of parts. You can
> "impregnate" a material with thin epoxy if it is
> quite porous. Beech is pretty darn dense stuff. You
> will not be able to "impregnate" beech with epoxy.
> 
>   I'm very curious about the questions above. I look
> forward to your descriptions.
> 
>   Terry Farrell
> 
>   > Does anybody know how to do this? It's going to
> be a great piano. 
>   > I've promised to get it back to the  church for
> Easter.
>   > 
>   > Bill Ballard RPT
>   > NH Chapter, P.T.G.
>   > 
>   > "Lady, this piano is what it is, I am what I am,
> and you are what you are"
>   >      ...........From a recurring nightmare.
>   > +++++++++++++++++++++
>   > _______________________________________________
>   > pianotech list info:
> https://www.moypiano.com/resources/#archives
> 
>   As far as impregnating beech with epoxy,  I don't
> know..... I would go for all new jacks.
> 
>           David Nereson, RPT


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