Thursday, 22 April 2010

Chapel Studios Continued....

The next project I worked on at Chapel was the restoration of a face. The studio didn't know which window it had come from, how old it was or who made it, only that they had had it a while. It was very badly broken so it is likely that they removed it from its window when restoring it and made a copy to replace it instead of repairing the original. This project is really split into two because I was given the challenge of both restoring the original face which I will go on to discuss in a moment, and also copying it to make a replacement in which I will discuss later. It has been very useful to me to see both ways and be able to compare their success.

The first thing I did was clean the broken sections of glass and tape them back together with magic tape (because it is low tack). I cleaned them using de-ionised water and cotton buds. I cleaned the edges with a dry (not wet as I was instructed in Holywell) fibre brush. I went over the edges a second time with acetone and a cotton bud. Some of the original glass was missing, perhaps it had been so turned to powder in the damage that it wasn't kept, or they had been lost over time. I went downstairs to the glass racks to match the colour of the glass, and from this I was able to cut two inserts. I painted them to match the panel, first guessing where the trace lines would have been and firing those, then attempting to copy the faded matt by scratching it to give the impression of erosion. The Ancient Brown paint was

(Fig 15. Image showing face panel to be restored)

mixed with vinegar for the tracing and Bistre Brown was mixed with gum arabic and water for the matt. Both were fired to 680C. Once fired I taped them into position.

To glue the panel back together I first covered the back of the glass with vinyl, then dental wax to give the glass strength and fix it in position. This also stops the resin from seeping out or the glass from becoming stuck to the table. The glue I used was araldite and I measured the amounts out by eye. The resin was coloured in the same way the silicone was in Chapel Panel. In Holywell we resined cracks by dabbing tiny dots of glue along the cracks, this would then seep into the crack and the same dot would have more glue added until the crack was full and the dot no longer moved. In Chapel they did it a different way, dragging a knife with the glue on along the crack to encourage the resin to flow into it. After a couple of days the glue was completely dry and I then needed to fill in the shales and air bubbles left on the opposite side. I didn't need the vinyl and wax this time because I was only doing a small amount and it would no longer be able to seep through but I put the glass on a piece of paper just in case so it didn't adhere to the tabletop.

It was important while filling in the back that the araldite was not too lumpy and stayed flush with the surface of the glass. That's because I was about to cut a duplicate from the same thin float glass I'd used before to go on the back. Because the glass was so thin the very tricky angles that the original thicker glass had accomplished became very hard to manage. On the first couple of attempts flies in the glass forced me to start over and when I asked one of my mentors to help she had the same problem. Eventually we managed to cut, what were practically right angles and I ground back the edges to make it fit snugly. I matted a very light bistro brown was on the back of the back panel. This was light enough that it didn't change the colour of the original panel but would remove the shiny reflective quality of the glass when completed. This is done so when the glass is in-situ people are not distracted by glints of light.

The studio had a larger flat bed electric kiln and I sieved whiting onto a section of this. It had to be quite thick because we were going to use it to slump glass. I took the original face and coated the back again with vinyl. I then added two sellotape handles to it so it could be picked up without touching the edges. This was then pressed into the whiting so the whiting took on the contours of the glass. The replica face was then placed into this shape to be slumped to form the same shape as the original. This way when they are later attached together they will fit perfectly without gaps. The kiln was still only taken to 680C but of course being electric it took a lot longer.

(Fig 16. Image of original panel restored)

I then set about cold colouring the original face on the front and the back. The vehicle that is used for the colour is a clear substance called paraloid B72. It comes in gel crystal beads which are stewed for fifteen hours or so in de-acetone alcohol until they turn to a liquid. This is a conservation resource that is also used in other types of restoration such as restoring marble statues. It is acetone soluble but waterproof. Chapel does not cold colour with acrylic paints like in Holywell, because they believe this is better and say it is more durable. It is mixed with pigment in powder form like the glues before and in this case a brown to mimic the original paint work. This is painted on everywhere the paint is eroded and once completed the effect is really startlingly better than before. The two separate pieces of glass were later plated together with silicone. I was very impressed by how well it could be fixed.

While restoring this face, as I mentioned before, I was also tasked with creating a duplicate. I traced the original and cut a piece of spare glass from the rack in a similar shade. I lay this duplicate on top of the original so I could look through the glass and so trace the design. First I copied the trace lines, with bistro

(Fig 17. Image of original with tracing paint copy)

brown and vinegar, which I felt I did quite well but some of my strokes were thicker in places than the originals and the tips of my strokes were not always sharp enough. After this was fired I painted a matt layer onto the head. I was shown how to age this by first letting the matt dry. Then spraying a plume of water into the air and waving the painted glass into it so that it picks up all the dots like light rain (apparently glass cleaner also works well at this if sprayed making a different effect). When you then work into this after it's dry with a scrub or stipple brush lots of dots show up. This produces an aged effect in this instance but could also be used in contemporary work.

In the end I fired on two different matt's using this technique because I wasn't happy the first time. I didn't feel my shading was quite right and I thought it was a little light so I did a second darker matt over the top. The result had more depth and shadow than the original, but I liked it for this. As we planned to fix the original I was allowed to keep the replica.

(Fig 18. Stippling matt replica to look like original)

I set about planning a border for it so the whole thing would be the size of an A4 piece of paper. I chose a wavy 70s sort of pattern and picked glass I thought complimented this. I cut and ground it and used the same dot matting technique on it as I used on the face so they looked like they belonged together. I made a mistake though and I fired it too high, about 100C out, when I lost track of time. Some of the pieces became warped and needed to be re-cut and they all needed to be repainted. When it was all finally done and fired to 680C I was very happy with the results.

I leaded my design together using ¼ inch round lead for the inside detail and ½ inch flat lead for the outside. I finger puttied it and polished it with a brush. I cleaned up the detail with tissue and cotton buds dipped in acetone. When this was done I added copper hooks inside the top lead so they were near invisible but could hang it. I am very happy with the results and am really proud of this panel because it was my own design and with it I had tackled a lot of techniques I'd never used before.

Fig 19. Image showing my finished design incorporating replica face


  1. Very nice work and very detailed description.I really like your background,70's or not! Shane

  2. This is an aspect of stained glass I've never really considered....very nice, and love the history of each! Very intrigueing.