Cracked Plates/"Can't be welded"!

[Kdivad@AOL.COM]

---------------------- multipart/alternative attachment
In a message dated 12/14/01 12:32:50 PM Central Standard Time, 
JD@Pianomaker.co.uk writes:


> Yes, perhaps I should not have made such a general statement.  I 
> accept cast iron can be welded and welding "in the factory" is one 
> thing.  Another thing is repairing a crack where a bar joins the web 
> on a grand piano.  I'm no welder, but I understand that in order to 
> remove the stresses caused by welding, the whole plate needs to be 
> heated to a very high temperature.  This would completely destroy all 
> the priming,filling and bronzed finish on the casting and require all 
> this very time-consuming work to be done from scratch.  I've been 
> through that once and I don't fancy going through it again on an old 
> casting.
> 
> 

JD,  there is a lot of misinformation out there about welding plates and one 
of the lines is that the entire plate needs to be heated, absolutely untrue!! 
 A good welder can "V" groove the crack and fill the crack a layer at a time. 
 This is a safe operation and my colleagues and I have pianos out in the 
field with welds for over 25 years.  No failures.  
Not mentioning names, there was a "rebuilder," term used very loosely, in the 
northeast who used to say that he had Steinway fly him in plates by 
helicopter because he was the only person able to weld them.  Part of his 
hype was that he would heat the entire plate and keep it at a specific 
temperature while he welded the crack and then he would cool the plate in a 
specific manner so as to keep the "bell tone".  I was suspicious because none 
of this heating damaged the finish on any of the plates I saw.

David Koelzer
DFW

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/44/c0/1a/0b/attachment.htm

---------------------- multipart/alternative attachment--