Mechanical Music Digest 
You Are Not Logged In Login/Get New Account
Please Log In. Accounts are free!
Logged In users are granted additional features including a more current version of the Archives and a simplified process for submitting articles.
Home Archives Calendar Gallery Store Links Info
MMD > Tech > mfudge_pouches


Spring Fundraising Drive In Progress. Please visit our home page to see this and other announcements: https://www.mmdigest.com     Thank you. --Jody

Duo-Art pouches
Duo-Art Valve Pouches
by Mark Fudge (030122 MMDigest)

mfudge_pouches.jpg (42 kb)
[Larger view]

I'm currently trying to solve a vacuum loss problem on a 1922 Weber pedal-only Duo-Art, or "half Duo-Art" as they seem to be known in the UK.  Through testing each component I eventually traced the suction loss problem to the player action stack itself.

The cross valves seem to be in good order and there is no obvious damage which would suggest that facings, etc., are causing the problem.  However the pouches seem to have been replaced at some point and don't seem to have the "mobility" of original Aeolian pouch leathers, and I suspect that these are causing a significant amount of loss.

The attached picture shows that the pouches have crumpled somewhat, and some have almost developed a tendency to spring, thus preventing the valve to sit correctly.  I'm wondering if the leathers have dried, and also what may remedy this situation.  I'm loath to replace a whole set of pouches and ideally see this as a last resort.

There were also two other possibilities for suction loss.  The striking pneumatics appear to have been glued on without any paper gasket, and each deck had been sealed with a form of sealing tape similar to duct adhesive which had, I suspect, started to lose it's ability to hold vacuum effectively.  I'm planning to replace this with the normal rubberised cloth.  Do these sound viable as a source of vacuum loss, and is it safe to use a sealant tape?

I'm also trying to locate a supplier for the small collars which fit to screw heads which are used to fix the pouch board to the valve deck and seem to prevent the screws from "digging" into the wood of the pouch board itself.  Any ideas?

Mark Fudge
22 Jan 2003 19:08:55 -0000


12 February 2003

Home    Archives    Calendar    Gallery    Store    Links    Info   


Enter text below to search the MMD Website with Google



CONTACT FORM: Click HERE to write to the editor, or to post a message about Mechanical Musical Instruments to the MMD

Unless otherwise noted, all opinions are those of the individual authors and may not represent those of the editors. Compilation copyright 1995-2024 by Jody Kravitz.

Please read our Republication Policy before copying information from or creating links to this web site.

Click HERE to contact the webmaster regarding problems with the website.

Please support publication of the MMD by donating online

Please Support Publication of the MMD with your Generous Donation

Pay via PayPal

No PayPal account required

                                     
Translate This Page