Depending on the organ, its position, frequency of use, and other contributing factors, it will need the more in depth cleaning process. There is no strict time frame when this is required, but cleaning is usually carried out every 20 to 25 years. This would be advised on your inspection or visit. This requires the removal of all pipes which are transported to the workshop to be cleaned and repaired if needed. Action components are removed and cleaned. The soundboards will be thoroughly cleaned and the tip boards, slides and tables will be removed to check for any damage and cleaned and re-treated with black lead. At this time, any remedial work can be carried out.
The instrument once clean is re-assembled with the greatest of care with particular attention to the speech, regulation and tuning of each individual pipe.