The overhaul of an organ is required when the above cleaning process would deem unviable and this would usually be carried out around every 50 to 60 years. The overhaul process consists of dismantling the organ and the major parts returned to the workshop. All the pipework will be cleaned, rounded out, repaired where necessary and placed on the voicing machine for checking of speech. The soundboards on which the pipes are placed with all the valves and springs within are stripped down, and planed up. The pallets are all recovered using traditional sheep skin in double or triple thicknesses or with felt and leather depending on the history and action of the organ. 
The bellows are removed if at all possible to the workshop, inspected for any leaks and damage, and attention to the leather work carried out or re-leathered if required.
We only use the traditional Salt and Alum Sheep Skins and traditional Hot Glue.
All action components are returned to the workshop and overhauled. New centre pins are fitted if deemed necessary, or components are rebushed.