On the subject of sealing leather pouches, may I offer a few

thoughts.  We are professional pipe organ builders in Lancaster County,

Pennsylvania, and we use leather from Columbia Organ Leathers.  We have

used their white "CPL" leather in our windchests for years and the only

time that we seal it is in ventil windchests where there are times when

air is only on one side of the pouch.



The "CPL" leather is somewhat porous, especially in the thin and extra

thin product.  In pitman chests there is always air on both sides of

the pouch and a sealant is not needed.  When needed, we use thinned

rubber cement to seal the pouches.



Recently Columbia has introduced a new product -- a red "RML" leather

which is virtually airtight.  "RML" refers to Robert Morton Leather

and is similar to the leather used in Robert Morton theatre organs.

The only drawback we have found to the "RML" leather is, that since it

is much more airtight, the leather is harder to "dish" than the "CPL",

so care must be taken to allow for dishing in the gluing process as

opposed to after the glue has dried.



Feel free to look them up on the web: http://www.columbiaorgan.com/ 

Larry Pruett is the leather guru there and he can assist you in

selecting the right materials.  Their product line is amazing --

virtually everything you need to restore where leather is used.  They

also have a full re-leathering service.  Hope this helps.



Harold Ulmer - SDG Organs

Millersville, Pennsylvania

http://www.sdgorgans.com/ 

hdu@sdgorgans.com.geentroep [delete ".geentroep" to reply]