interesting topic.
Reed plates: waxed or pinned. Many opinions on this subject.
There isnt much information on this topic to be found online, only scraps and bits of info.
(Maybe the forum could invite people from the accordion making industry to give us some more detailed information).
http://www.lucas-accordeons.com/les-sommiers
Il existe des musiques cirées et clouées. Cest juste un choix du fabriquant qui ninflue pas vraiment sur le son. Les musiques clouées présentent lavantage dêtre facilement démontables pour accéder aux anches ou aux cuir tournés vers lintérieur du sommier. La cire demande dêtre remplacée pour démonter un cadre (attention cest une cire spéciale), avec le nombre des années elle sèche et se craquèle, ce qui désolidarise les cadres du sommiers et provoque une vibration forte et désagréable. Auquel cas il faut remplacer la cire, lidéal étant de nettoyer tous les sommiers et den remettre une neuve car tôt ou tard dautres notes subiront le même sort.
Nails and leather have been used in Schrammelharmonikas and early accordions with very good results, but one had to be careful not to damage or perforate the reed chambers, as shown in one of these photos:
http://www.accordeon-special.de/reparaturen-1.html
Today wax is used, but pins and nails were also a very good method. Perhaps the nailing or pinning method took more time and care to make.
This is information directly from the Italian accordion community on accordion production, its also talking about the wax
http://www.strumentiemusica.com/not...ilizzati-nella-costruzione-della-fisarmonica/
Some accordion repaires would like to go back to the nailing/pinning method, because its easier for replacing and repairing. Wax dries and crumbles, it can be messy to clean and repair. The naling/pinning on leather method is cleaner, but perhaps more labor intensive to make.
Leather also dries and becomes stiff after years, but when the accordion is kept in good climate conditions, leather can last for many years. Leather chamois or leatherette with the right thickness could be used, but only if it doesnt hinder the sound/vibrations on the reed blocks. But if its been firmly (but carefully) pinned or nailed, the reed plate can be pressed down a little bit into the leather chamois. After a few years these markings leave small grooves or channels of depression (?), that can hold the reed plates firmly.
When the wax starts crumbling and disintegrating, the wax no longer has the force to keep the reed plates firmly in place on the reed block. The intensity of the vibrations make the reed plates become loose, and sound quality and air pressure conduct is very poor.
http://www.accordionrevival.com/ACCORDION_REPAIR1.php
Old brittle wax transmits sound differently. Fresh wax could make your accordion sound more like it did when it was new. However, re-waxing is very time consuming and expensive. If you pay to have it done, the cost could exceed the market value of your accordion.
Its not really clear what is best for sound transmission, the wax or the leather/pinning technique. Both seem to have good sound qualities in quality accordions. Maybe wax could transmit vibrations of the reeds and reed plate better, its possible. I am not aware of scientific studies on this issue, but the accordion industry must have some test results about this topic. If they will publish this information, thats another thing.