The best type of soldering iron is an adjustable thermostatically controlled one. Solder melting temperature boils the wax too easily, leaving a nasty black sticky residue.

A company called 'Skytronics' up here in Manchester (England) does an excellent, fairly cheap one for around thirty quid, but they are trade only.

You should be able to get the right wax from Allodi in London - Emilio is very helpful.

Older accordions with leather reed valves will also benefit greatly from having plastic valves installed, as they seal much better and aren't prone to curling. If you are already having to replace the wax, it's a good opportunity to do it, and the instrument will take much less effort to play!

E-mail me if you need more information...