University of Applied Sciences Fach-Hochschule - Continued

The next project that I worked on was a broken wine bottle. I broke the bottle and then taped it back together, removing a small section so I could learn about the process of creating a 3D infill. The first step was to work out where, following the cracks, was the best place for me to separate the glass into two halves. This is so you can get your hand up inside it to tend to the infill from both sides before fitting it all back together. When I decided where I would remove the bottom from I glued the top half together being careful not to resin this section on. The reason I didn't remove the bottom before doing this is so the bottle held to its original form and didn't warp without the support of this part. I was told I could either stand the bottle up and resin it that way (apparently if you are careful it won't drip down) or you can lay it on its side and resin it in two parts, letting the first dry before rolling it over. I opted for the latter.

(Fig.4. Broken bottle taped back together.)

In order to make the mould, which I did once the cracks were resined, I used a two part silicone mix, one part silicone to one part hardener. Once mixed together they set within five minutes. This particular brand was called 'dentasil light' and was used in dentistry. Once the glass was clean the first step was to pick another part of the bottle which mimicked the contours of the area I wanted to fill. I then spread the silicone mix onto this in a square shape larger than the hole and in a consistency thick enough to be easily handled without it coming apart or losing its shape.

I repeated this process twice, once for the shape of the inside of the bottle and one for the outside. The silicone I spread on the outside I did in the same way with one exception. I held a small section of drinking straw onto the glass firmly while I pasted the silicone around it (this is easier with two people). This was done so that once it was set the straw would act as a funnel I could inject the araldite into, and also act as an air vent to release any trapped bubbles. In larger moulds you will need two straws one to act as an air vent and a separate one to pour but because mine was so small this wasn't an issue.

These two mould sections are then stuck to the inside and outside of the site needing infilled in turn. They are fixed using extra silicone which is applied thinly with a finger around the edges of the hole, being careful not to get any into the area for gluing, and the mould

(Fig.5. Mould made of dental silicone with straw)

is then pressed into it until set. This was a fiddly business for me because it was very hard to get my hand far enough up the bottle to do this at all never mind doing it with any delicacy. It is very important that the silicone mould is stuck firm otherwise the araldite will seep under it, the mould will fail and the after effect will be very hard to clean because it is so hard to get to. I found this to my peril on my first attempt. It is also worth noting that once the mould is in place the araldite must be applied very slowly so as not to create bubbles, a little at a time. The longer it is since you mixed the araldite the thicker it will be and thicker glue creates more bubbles because the air finds it more difficult to escape. If bubbles do occur, rock the glass from side to side to try and chase them up the air vent. If this doesn't work, or you can’t see them because the mould is not clear then use fresh araldite and hopefully they will rise to the surface. Surface bubbles can be easily filled in once the glue is set and become invisible.

Although in the end my infill worked, for the sake of experimentation I removed it in order to do it again using an alternative method. This time I used wax. It works on the exact same principal, one piece inside and one outside. Although instead of the straw you cut a small hole. At the university they had a special little drill to do this with but I imagine you could do the same thing with a sharp pencil. Where as in previous studios we always used a hair-drier to soften the wax here they had another special tool. I used an electric metal spatula, plugged in like a soldering iron, which when heated could be pressed into the wax to seal it to the glass. This of course was accidental, because I could never have fitted a hair-drier into the bottle. This time I had premixed powder pigment into the araldite so that when I added the hardener I was able to perfect the colour by adding a little blue and a little yellow to create the olive green of the bottle. I injected this a little at a time through the hole in the wax and into the cavity, swaying the bottle to let the liquid

(Fig.6. Alternative Wax Mould)

reach the corners first before adding more so as not to get bubbles. Once hardened I felt that this method had worked very successfully and I found it easier personally to use the wax rather than the silicone.

The final item I had to break and fix was a lightbulb. This process was exactly the same as the others. The curve of the surface made it marginally easier the fit the pieces back together but many were so tiny, the glass so thin and fragile, that it really was an extremely difficult job. In the end I had to glue one half before I could continue reassembling it because it was so delicate that even with tape it kept coming apart in my hands. The final pieces were so small they had to be fitted using tweezers and the task was so arduous at times that it seemed like it was un-accomplishable. I did witness another student finish one, so I can testify to

(Fig.7. Taping broken lightbulb)

the fact that I have seen it done and it is therefore possible, but as I had such a short stay there I will admit that mine got the best of me and was never fully realised.

Award For Excellence - University of Applied Sciences Fach-Hochschule

In the last forty weeks I have been travelling around different glass studios and institutions as an award recipient of the Award for Excellence, bestowed to me by the Worshipful Company of Glaziers and Glass Painters. This is the third and final instalment of my report on what I have learned during this time and how this new knowledge has influenced me as an artist.

On this, the final leg of my journey, I have had the pleasure of travelling from the East to the West of Germany and then on to the highlands of Scotland. I have spent time at four separate establishments, which have each taught me a great deal. I first visited the ancient City of Erfurt in what used to be East Germany where I had the privilege of working under the tutelage of Professor Sebastian Strobl at the University of Applied Sciences Fach-Hochschule Erfurt. I then toured Glasmalerei Peters and both their studios in the Cities of Paderborn and Neuenbeken where I was watched over by Jan Peters. Next I travelled to the town of Wehen in Taunusstein where I worked at Derix Studios under the instruction of many different employees. After leaving Germany and returning to Scotland I had my grand finale in Lybster, for a brief stay at North Lands Creative Glass to assist at Catherine Newel's Masterclass.

Throughout the course of this report I will discuss each of these placements and what I learned from them, and I will do so in chronological order, commencing with my stay in Erfurt.

Professor Sebastian Strobl runs the glass section of a department specialising in conservation and restoration. He has a particular interest in resins and glues in regard to the repair of broken or damaged glass. The three weeks I spent at the University of Applied Sciences were therefore mostly concerned with this, but I also got to observe other restoration work that was going on in the studio and take part in a little myself. The main projects I worked on while in Erfurt in regard to resin were the breaking and restoring of several items, (namely a sheet of float, a bottle and a light bulb), and the creation of a glass tray. I also worked on my own conservation project of a small panel from Benburg and participated in the early stages of conserving church windows from Dondorf.

I am first going to discuss the work I did in resining. This is something I had already done at several of the studios over the course of the award, but here it was done a little differently. It is possible that certain techniques are specific to Germany but I think in this case it is simply that there is no 'one' way of doing it but in fact a multitude of varying possibilities and people just grow accustomed to their own. I think that Professor Strobl, who was in charge of the restoration of the glass at Canterbury cathedral for a long time, perhaps had a stricter view on the ethics of restoration and conservation than some of the other studios I had worked for, and it was very interesting to learn from him some of the debates that rage over the proper and correct ways of doing things.

For example, the first task I was set at the university was to smash a piece of float in order to learn how to glue it back together again. Although this was something I had done before, it was interesting to learn the differences between how it was done here and how I had been taught to do similar jobs previously. In another studio I had been told that when restoring glass, if there is a fly (the beginning of a crack) in the glass it is necessary to break it, as delicately as possible and in a manner where it will be least conspicuous. There are two reasons for this; firstly because a fly is unstable, it will eventually run its course due to the retraction and expansion of the glass, or other stresses. If you break it, you can then mend it, and this will make it secure. This is prevalent particularly if the glass is then to be returned to somewhere that cannot easily be got to, such as high in a church, and therefore may not be repaired when broken for some time, and could when eventually broken even fall out and be lost. The second reason I have been given why it is important to always break flies is that they cannot be properly resined to the end (because the cracks become very tight and the glue cannot slip along them) so they will continue to glint (shine when the sun’s rays hit them) and this draws attention and is unattractive.

Strobl was horrified when I informed him that I had been told this. He said it was important that flies are never broken with pliers but left as they are. He believes that the principle is to protect glass no matter its age or our personal views on its artistic merit, it is all of equal importance and must be preserved. In his opinion glints are not that obvious and if the glass is treated well there is no reason for flies to break. I am not sure I have developed a definitive opinion on this matter, but it was interesting for me to hear such widely differing opinions on the subject and that is why I have included them.

Once I had smashed the sheet of float glass with a hammer (something that was thoroughly enjoyable) I then had the job of piecing it all back together again. This took me a number of days and when I was finally successful in completing this mammoth jigsaw I was irked to find I was missing a section. When preparing it for resining I was instructed to do it in a more relaxed manner. Instead of cutting

(Fig.1. Preparing float glass for resining.)

small strips of tape and joining each shard together meticulously so the surface was flush, I was instead told to only tape it where completely necessary and judge the surface by eye. Tiny squares of wax were cut to sit under the glass in order to hold it off the table and support it so it was roughly level, rather than the combination of great strips of vinyl and wax that I had been used to. The reason for this was because Strobl believes that the wax and vinyl done the way I had been taught was likely to damage the glass or pull off the paint and the same went for the tape. In Erfurt they chose an uneven surface over possible paint loss, and once I had glued it with Araldite the glass seemed just as secure even though the outcome was less smooth.

For my own interest I tried an experiment in order to see if there was an easier way of re-glueing a panel like this for artistic application without the time consuming jigsaw routine. I cut a new sheet of glass and securely taped up the back of it so the whole surface was masked. I then tried once again to smash it with a hammer. The first few times it did not break at all, which must be due to the tape strengthening the glass or absorbing some of the impact, I conjecture in much the same way that laminated safety glass works. When it finally broke the tape held it together and I could apply the resin without having to reassemble it. It also resulted in a completely flush surface.

I used a red pigment in the glue to make the cracks visible and because I thought I would appreciate the aesthetic result. The powder pigment was mixed with the araldite (not the hardener) the night before and sealed in a small container. Strobl said this was often done in order to dye the

(Fig.2. Smashed float with tape on back and red pigment in cracks.)

araldite to the colour of the broken glass, especially in the case of infill's (where a section of glass is missing and araldite is moulded into the space as a replacement), so cold colouring is not needed after. The next day I mixed the two part resin together as usual and applied it using a syringe, which is their chosen tool. I can definitely see the benefits of the syringe because as well as applying the fluid it can also suck it back up if you have added too much. The down side is it injects bubbles into your cracks if you don't let it sit for a while and tap it first and even then it did seem prone to doing this, although it could have just been my poor handling. Another advantage of the syringe, over say the use of a metal instrument like a dentists pick, scalpel or wooden stick, all of which I have used in the past, is that the araldite can sit in the syringe for hours without hardening or thickening too much and so you do not end up throwing loads of the solution away, you can simply wait until you are ready to do your next project and then use it again.

I put quite a lot of the pigment into the mix, which you would be unlikely to need to do in a traditional setting, because I wanted my cracks to be tinted with a very strong colour. Although the pigment had no effect on how well it stuck, which had been a concern of mine it did make the mixture a little blobby and so was hard to apply neatly.

I was very happy with the results in both these projects. The first needed a little more work because of the missing section, and the hole that was left when the glass turned to dust at the strike of

(Fig.3. Both smashed and resined float sheets layered together to show the results.)

my hammer. This I filled with araldite in much the usual way, except instead of using vinyl and wax I just taped the back with magic tape and filled in the front. This worked just as well and was a lot more straight forward, although would not be practical for larger applications as the lines left by the edges of the tape where they have joined together would be visible.

With regard to the mending of broken glass in conservation, there is an argument that araldite and other glues like it are too strong. This is bad because if there is a strain on the glass again and it breaks, it make break in a different place thus causing more damage. In order to make the repair less strong it is possible to apply paraloid to the edges of the crack and let it dry before resining the normal way. This makes the bond weaker.

Another problem with araldite is that over time it has been known to yellow. The formula is better than it was twenty years ago, so it shouldn't happen to the same degree or so quickly, but it is still a consideration. Strobl told me that some conservators choose to dye the araldite black as a solution to this, in order to make the repairs obvious and prevent yellowing. It was however his opinion, as it is mine, that this looks much worse, and the possibility that it may go yellow in the future is much preferable to it going black now.