Projects
Full restoration of Church windows at Holy Cross Church Uckfield Sussex
Full restoration of heritage glass with new English hand drawn lead came.
CONSERVATORS REPORT FOR THE
CONSERVATION OF STAINED & PAINTED GLASS.
P.A.C.R. I.C.O.N. Accredited Conservator- Restorer Mr C G Durant
DATE: 30.08.2019
LOCATION: The Church of the Holy Cross, Uckfield.
CLIENT: Mr Paul Kennedy
WINDOW LOCATION: South Elevation. gallery staircase window
WINDOW DESCRIPTION.
A two light window triple cusped, stone surround with historic clear glass traditionally leaded in a diamond pattern.
ARTIST: Unknown
CONDITION:
Both lancets are in a poor condition and will need to be carefully removed for restoration with new English hand drawn lead came to match the original. The ferrous iron saddle bars have deteriorated and are rusting to a point where the tips are damaging the stone jambs and mullion.
There are signs of copper ties broken allowing the leaded panels to bow.
Water ingress is visible with staining to the sill.
2.
Lead — We will make an inspection of the existing ‘lead came’ to ensure that an exact match is used in the rebuilding in leaf, heart height and heart width also thickness of the lead heart.
The overall condition of this lead is:
Surface oxidisation is heavy having lost an estimated 15% of it’s original volume through oxidisation and erosion resulting in cracked soldered joints.
We carry a vast stock of hand drawn ‘lead came’ to some 6 tonnes in a selection of some 23 differing sizes, should we find as we sometimes do, that we do not have an exact match then this will be made to order. We use only traditional hand drawn ‘lead came’ from original Sharratt & Newth lead mills as used in the seventeenth eighteenth & nineteenth centuries.
INSURANCE:
We are insured for 5 million pounds sterling.
CONSERVATION PROCEDURES:
Before beginning any work, a record will be made of the glass insitu, including a site report which will include historical information, photographs and details of particular items of importance.
Once the glass is in the studio, rubbings of all lead lines will be made on paper, so that further information can be recorded before, during and after the various stages of conservation work. This work is especially important with fragmentary windows where previous restorations can also be noted.
Detailed records of all the conservation projects is absolutely vital for the future of the glass, should there be any subsequent damage.
Minimum intervention is a byword of current conservation practice and we must bear in mind that the stained glass may not need any treatment at all.
Minimal cleaning with a de-ionised water will allow light through the window without risking damage to the paintwork or scratching the glass surface.
3.
The level of intervention for any particular conservation project will be affected by a wide variety of factors, all of which will need to be considered at an early stage.
A fundamental principle is that conservation techniques should be reversible. Reversibility allows for the possibility of future developments in conservation, this will allow repairs to be removed or reversed should this be required.
Solely techniques and materials which to the best of current knowledge will not harm the panel or impede future treatments will be used.
Our intention here will be to fully restore these two lancets glass with new English hand drawn lead came as the existing condition has left these two windows weak. Once the two lancets have been carefully removed and securely boarded we will transport them to our Horsham conservation studio.
An air extraction bench is used during the careful stripping down of each panel, every piece of glass will then be cleaned with de-ionised water.
Each piece of glass will be laid in it’s exact position on the 1st rubbing.
At this stage if broken or missing glass is found this this will always firstly be looked at with an eye to conservation rather than replacement only if found that it is beyond conservation then a new piece of glass be selected and replaced as close as possible to the exact type of glass in colour, tint, striation and thickness.
Should the glass be cracked rather than shattered with all or most pieces present then we would look into conserving the original glass by one of three methods.
- Adhesive edge jointing with a specialist hxtal resin.
- Adhesive jointing combined with plating with 1mm plates which will be kiln formed to exactly the shape of the conserved glass.
- Copper foil jointing as fine as possible. And soldered taking care that any flux is kept away from the fired surface.
Rebuilding on the original grid work rubbing will then begin with the selected hand drawn lead came matching profile and the exact original sizes in both heart width and height, once rebuilt the panel is soldered with a 60/40 tinmans solder at the joints, once complete the panel is carefully waterproofed with Hodgsons black lead cement taking care not to touch the glass surface more than is absolutely necessary.
Once the lead came is polished, (again making sure that the polish is kept away from the main glass surface and painted oxides, 16/18 swg copper ties will be applied to soldered joints for attachment to the saddle bars.
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GLASS CLEANING:
Cleaning with deionised water under conservation conditions, does not at any time include the immersion of glass, rather a fine delicate touch with cotton buds in a controlled localised pattern to remove a dirt build up.
IRONWORK SADDLE BARS:
Ferrous metal bars where they touch the porous stone work, which then corrode will be changed to non-ferrous stainless steel or brass and paint coated during the restoration if required to eliminate any suggestion of further corrosion.
ACCREDITED CONSERVATOR:
The personal Accreditation of a Conservator/Restorer (P.A.C.R.) through the Institute of Conservation (I.O.C.) Is attained solely through excellence in practice and minute attention to detail in every aspect of your chosen subject, Accreditation is hard to attain and guarded preciously, each Conservation Studio is inspected, their procedures dissected by eminent practitioners within this field,
Conservation records and photographs are always kept safely.
RESEALING & POLISHING LEAD CAME:
This Report explains exactly how glass will be conserved and by a range of methods once a close inspection has been completed, only under conditions where glass cannot be conserved will new glass be sought to match exactly the original, each new piece of glass will be finely marked to show its date of replacement.
The lead is new English hand drawn came which will be polished upon completion, this is a practice that will help to seal the raw lead and protect it from the elements and oxidisation, when applied it will not come into contact with the main body of stained & painted glass surface during application..
GLASS: We carry good stocks of glass to 6 tonnes, this stock being English Hartley Wood from the 1980s, English Antique Glass from Birmingham, French St Gobain, German Lamberts and early Fischer.
We also stock or can obtain glass from Poland and America of certain types which include flat antique, seedy, reamy, flashed, pot metal, opalescent and traditional drawn sheet.
RE-INSTALLATION.
It is important that the mortar for re-installation of the new outer seal is as soft as the stone itself, therefore a hydraulic lime based mortar will be used with a semi sharp washed sand.
We keep stock of various different materials to attain the optimum mix, such as Minsted sand, Washed semi-sharp sand, Mid coloured washed sand, stone dusts from – Portland, Bath, Ham, Cotswold and a range of limes from England and France at a strength of 3.5% and 5%. the mix will be matched as closely as possible to the stone in hardness and colour, applied, dressed and compacted to a fine finish.
The original mortar is a lime based mortar with some re-pointing of Portland cement, this cement will be removed. Stonework rubbing will be been taken.
PROTECTION: security boarding protection will be placed over the aperture during the restoration process fixed with threaded rod to 100 x 50mm timbers internally whilst the windows are in work. The threads will be destroyed externally to decrease the likelihood of access being gained.
This Glass Conservation Studio does not subcontract, all Conservation projects are completed in house.
