Framing England's History: A specialist insight.

Churches Conservation Trust works with specialist craftspeople to conserve and repair, and to minimise the environmental impact on the historic windows in our care.

Meriel O'Dowd is the Conservation Project Manager for CCT’s “West Region” and she has recently commissioned Bob Tucker from Heritage Stained Glass to carry out a major conservation project on CCT’s new vesting of St Torney’s Church in North Hill, Cornwall. Meriel stresses the importance of this work, saying that:

 “Stained glass can be one of the most beautiful decorative arts in a church telling timeless stories. CCT looks after internationally important collections of stained glass such as that at Shrewsbury, St Mary’s, and it is vital that we use expert craftspeople to conserve these important parts of our history and collection.”

Bob Tucker has worked as a stained-glass conservator for over 30 years and now employs an expert team of three, who he trains himself for four years to become skilled specialists. At St Torney’s, Bob and his team are currently fully repairing most of its windows, where the lead matrix has decayed. The process starts with carefully removing the stained-glass panels, which are then taken to the workshop where his team clean them and take rubbings to create a template. The windows are then dismantled, and the leadwork recreated from new lead using the template of the original window. The glass is then put in place and the lead re-soldered. The panels can then be refitted. The lead used in windows has a lifespan of 100 years or so before it starts to deteriorate, after which the windows may become fragile and vulnerable to the elements once again. We look forward to welcoming many of our supporters to St Torney’s in October to celebrate the completion of this extensive conservation project. Please keep an eye on our website for more information of this special event.

Further conservation work is often needed to the iron bars that protect the window, which was the case recently at the seventeenth-century Low Ham Church in Somerset. The external bars, or “ferramenta” or internal bars called “saddlebars” are set into the stone surround. If these iron bars start to oxidise (rust) and expand, there is a risk that a “mullion” (the upright stonework between glass panels) or a “jamb” (the stone window surround) could split or shatter. In extreme cases, the metal can expand to the degree where the window surrounds are pushed apart. Bob addresses this issue by welding stainless steeltips to the iron ferramenta or replacing the thinner saddlebars with either stainless steel or bronze bars. Bob used a mixture of these techniques at Low Ham Church, which was completed in 2020, and at the current St Torney project.

Isothermal glazing is a method that has been used at the Church of St Mary the Virgin, Shrewsbury, to try to protect the glass from the drastic environmental conditions to prevent deterioration. By keeping the air at a similar temperature on both sides, we are able to prevent the build-up of condensation on the painted side of the glass. Weathering from condensation can result in painted areas deteriorating over time. This process involves taking the window out, repairing it as necessary and making a clear glass copy. The original window and the clear glass layer are then fitted into a rust proof bronze frame which is fitted back into the stonework with the original window being protected by the copy. Sometimes we find windows where the painted images have already deteriorated. The detail can be added again by painting onto a clear piece of 2mm glass that it fitted on the outside of the original-coloured piece, if this is deemed appropriate.  

Sadly, CCT  has a number of churches with windows in need of repair following vandalism. One such window was visited in August by the CCT Wiltshire Historic Church Tour at the delightful fourteenth-century St Mary’s Church, Old Dilton. St Mary’s was broken into and the school room windows struck from the inside, leaving the lead bent and numerous glass pieces broken. Bob explained that some repairs can be done on site. In these instances, leaded light cement is used to join the lead, rather than solder. If the damage is extensive, the panel would need to be taken to the workshop and the window opening secured temporarily with board. The glass panels can be very delicate in these situations but are in manageable sections that are divided by the lead. The lead forms a watertight seal between the panels and can be resealed when a panel is refitted using specialist tools. Any replacement pieces of glass are cut from handmade glass. The glass is repainted, usually requiring several layers of paint to make up the thicker and finer lines and shading. The glass is fired between layers and then put back into place supported by the lead.