Renner back action - spontaneous disassembly

[Porritt, David]

I've installed several of the Renner kits both the solid ones and the
laminated ones.  I've never had one come apart or show any signs of
weakness.  I'd guess that someone got distracted during the assembly
process and just didn't get the glue in that one.  It happens.

dp

David M. Porritt, RPT
dporritt at smu.edu


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On
Behalf Of Mike Spalding
Sent: Wednesday, February 27, 2008 8:07 AM
To: Pianotech
Subject: Renner back action - spontaneous disassembly

List,

Came back from KC last June all pumped up from Jude Revely's class on 
Renner back action installation.  For those who have not yet attended 
one, he builds on the Tim Dixon article in the Journal (Sep/Oct '01) to 
use  jigs on the bench to optimize the back action geometry, as opposed 
to just duplicating what was there.  Fixture uses scrap pieces of lift 
tray, so I pulled from my scrap bin the cut-offs from my most recent 
Renner backaction installation, which was also my first using Renner's 
new laminated tray (looks like Delignit, only thinner lams).  As I 
picked it up, it came apart in my hands !!!  Yes, the mortise-tenon 
joint seemed to have no glue in it, and it just fell apart.  The piano 
in which the rest of this tray is installed seems to be holding 
together, but to be certain, I'll have to pull the tray (!) and 
reinforce the glue joint.  The two kits I've installed since, I drilled 
and dowelled at several points along the length.
Called Lloyd, was told they'd never seen or heard of such a problem, but

they will support me in whatever rework/repair might be required.
Question:  Any of you other Renner users ever seen such a thing?  Users 
of other brands (S&S, Tokiwa) how do you like their product?

thanks

Mike