[CAUT] Key straightening; was Key Spacing: The Distal End

[G Cousins]

Jeff,
Yes, bows are dry heated to retain shape. Various woods require various timings. (duh) 
Most modern bow mfg. is in well controlled kilns. Traditional Brazilwood & Pernambuco woods have a substantially different bend differential time. 
Ribs are wetted (steamed) and different methodologies call for different techniques. (Think hide glue)  Time is the essence. 

I have used Roger's suggestion in some of the harpsichord warping with varied success. Would have to say that I believe much depends on the age of the key stick receiving the treatment.  Guess is that moisture content of the wood before during and after the might be the determining factor for success rates. Does anyone have a detailed analysis? Maybe Andre or the folks from Kluge. 

BTW  Love the jig design Alan (?). Have to make me one.  

Gerry 

From: tannertuner at bellsouth.net
To: caut at ptg.org
Date: Sat, 22 Aug 2009 11:05:05 -0400
Subject: Re: [CAUT] Key straightening; was Key Spacing: The Distal End












Violin bows are cambered using dry heat and no 
water, and as long as the bow is properly cared for, it will hold shape for a 
very long time.  The violin ribs themselves (the curved sides of the 
box) are wet before bending. Their shape is held by glue. We burn 
shanks without water.  It does take longer if you use water. Roger Jolly 
once told me to add thin CA once you've straightened the key. I haven't tried it 
yet.
Jeff

  ----- Original Message ----- 
  From: 
  Fred 
  Brown RPT 
  To: caut at ptg.org 
  Sent: Friday, August 21, 2009 8:51 
  AM
  Subject: Re: [CAUT] Key Spacing: The 
  Distal End
  

  
  What 
  I do to bend warp the key(just did a brand new Hardman Upright yesterday) is 
  place the key on its side at the edge of my workbench with the direction I 
  wish to bend it facing down. I then place a scrap of wood(bridge capping  
  maple works well) under the key button being sure that it extends past the pin 
  hole on either side. I then firmly clamp the key button area down to the 
  bench. I then measure how far the distal end(new word for me) sits above the 
  bench top(having already measured the distance I think I need to move it while 
  at the piano). I then place a clamp lightly tensioned on that end of the key. 
  Heat with heat gun for 5-10 mins adding tension to the clamp as you go. I feel 
  that the clamp gives me more control over bending forces than trying to lean 
  on it(although I do listen more the slightest ‘cracking sound’J). 
  I generally have to go 2-3x the distance I am looking for since the key will 
  tend to spring back when you release tension on the clamp. I like to leave the 
  key in the clamp for an hour to cool while I do something else in the shop. I 
  too would like to know if anyone has had success with adding 
  water.
  Fred 
  Brown RPT
  Atlanta, 
  GA
   
  
  From: 
  reggaepass at aol.com [mailto:reggaepass at aol.com] 
Sent: Thursday, 
  August 20, 2009 3:47 PM
To: caut at ptg.org
Subject: Re: 
  [CAUT] Key Spacing: The Distal End
   
  Alan 
  
   
  
  Nope, haven't tried that.  I see how that might work. 
   Our paramount concern is to not break the key stick, so we have been 
  doing everything possible to play it safe (like steaming both sides). 
   
  
   
  
  Alan
  
  

-----Original 
  Message-----
From: Mccoy, Alan <amccoy at ewu.edu>
To: CAUTlist 
  <caut at ptg.org>
Sent: Thu, Aug 20, 2009 11:51 am
Subject: Re: 
  [CAUT] Key Spacing: The Distal End
  
  Alan,

Have you 
  tried putting the key in the vise horizontally and steaming only one side of 
  the key (the “concave” side out to accept the steam)? You would then push the 
  key toward the bench to straighten it. The idea being that the side getting 
  the steam will expand more than the other side and would bend in the direction 
  you want it to go.

Just a thought. I haven’t tried 
  it.

Alan


-- Alan McCoy, RPT
Eastern Washington 
  University
amccoy at ewu.edu
509-359-4627 (message Pacific 
  time)
509-999-9512 (cell Pacific time)


  
  
  
  From: 
  <reggaepass at aol.com>
Reply-To: 
  CAUTlist <caut at ptg.org>
Date: Thu, 20 Aug 2009 09:37:18 
  -0700
To: <ilvey at sbcglobal.net>, CAUTlist 
  <caut at ptg.org>
Subject: Re: [CAUT] Key Spacing: The=2 0Distal 
  End

Key in vise (key button in vise jaws), distal end up.  We have 
  been running two steams sources, one on either side of the key, up and down 
  for one minute.  Then we apply pressure by leaning on the key in the 
  desired direction for another minute (no longer applying steam).  This 
  seems to do the trick in most cases.  Just wondering what problems we may 
  be creating in the process (so far, we had to ease a couple of key bushings 
  and replace a few more), or if there is an easier way to do 
  this.

Alan

-----Original Message-----
From: David Ilvedson 
  <ilvey at sbcglobal.net>
To: caut at ptg.org
Sent: Thu, Aug 20, 2009 
  9:20 am
Subject: Re: [CAUT] Key Spacing: The Distal 
  End

Alan,

How are you manipulating the key?   In your 
  hands, moving the key along the 
steam?  

David Ilvedson, 
  RPT
Pacifica, CA  94044

----- Original message 
  ----------------------------------------
From: 
  reggaepass at aol.com
To: 
  caut at ptg.org
Received: 8/20/2009 8:27:19 AM
Subject: [CAUT] Key Spacing: 
  The Distal End


>When spacing (i. e., bending) the portion of the 
  key between the balance pin 
and 
>the distal end (where the lifter 
  felt is) is indicated, does anyone have a 
technique 
>that works 
  particularly well for th em? C3 We are experimenting with heat alone 
  
(which 
>we have found to be extremely slow-going, so far) and with 
  steam (more rapid 
>results, but harder to contain than heat without all 
  that moisture in it). 
 Thoughts?



>Alan 
  Eder


 
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