glass beads

[Jennifer Barnett <reginatextilia@xxxxxxxx>]

Thanks to all those who have responded to my request for advice on wet cleaning and fractured/cracked/crazed blue beads that are stitched to a Berlin Work embroidery.
The use of cycldodecane is an interesting possibility but there seems to be (at least?) one disadvantage and that is that the canvas will also be impregnated, otherwise the beads could not be fully coated on the underside where they are in contact with the canvas.
I find it more clarifying to think things out by writing, so I might as well share the process and enjoy the synergy of your responses as a bonus. Please bear with me.
Closer examination, has revealed that the cotton canvas under the beads and the securing threads are white while the rest is "aged" light brown. The white fibres are strong, perhaps stronger than the rest of the canvas. The pH, measured with a 0-14 pH indicator strip, is about 8.5. It would appear that the beads have had provided an alkaline reserve for the cotton! The pH may or may not rise with time. There is no surface efflorescence<x-tad-smaller> </x-tad-smaller>on the beads<x-tad-smaller>. </x-tad-smaller>I would prefer to be able to wet clean it to lower the pH even though this would probably only be a temporary respite. However, the cycldodecane will no doubt prevent this. (No, I do not intend to try to lift and rotate each bead to coat it inside and out using a tiny brush).
At this point, I see two possibilities:
1 just wet clean and hope that not too many beads will shatter -> loss of (some?) beads, saving of canvas (some beads were wet during the pH measurement but did not break - hopeful)
2 apply cycldodecane and hope that the pH will not continue to rise in time -> loss of canvas -> loss of beads (Postponing the problem? How likely is this scenario?)
Ad 2    future loss of beads due to loss of canvas could be prevented by securing them to a support layer with a polyester thread. Should the canvas and thread rot away, the beads will remain in their original position. But I am sure that the handling involved, especially trying to pass a needle and thread through these quite small beads (next to the original thread or not) would also cause breakage. This is not a good idea.

I'll leave it there for now. Responses are very welcome.

Another article on the subject is "Deterioration of beads on an Edwardian evening bodice", Annie Lord, in Ethnographic beadwork: aspects of manufacture, use and conservation, Archetype Publications, 2001

PS
Since this sudden immersion in the stability problems of glass beads in connection with textiles, it seems as though the development of the problems is fairly recent or is it just the awareness that is recent? I am curious to know if it is a phenomena which needs time to develop and become noticable, as was the case with celluloid which seemed to disintegrate simultaneously over the whole world in the 80's and 90's. If it is a recent general development and not just isolated cases, then it would seem to be a urgent subject for research and funding in order to save late 19th century and early 20th century beaded costume and ethnographic textiles. The problem provides a variety of good subjects for students looking for a final project!

Jennifer Barnett
historical textiles research & consultation
Oude Looiersstraat 65-67
1016 VH Amsterdam
Netherlands
tel/fax ** 31 (0)20 427 18 27
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