Repairing a Broken Glass Negative
I bought a vintage glass negative that arrived broken due to poor (ie non-existent) packaging. It's a 6x9 plate that is now in approx 10 pieces - 5 large & 5 small. I should probably bin it, however I really like the image, which is why I originally purchased it.
So I'm trying to think of the best way to stick it back together again. I'm assuming this will be done with glue applied to the edges where they fit together. But what glue is best & are there any technique tips?
It occurs to me that this must have been a somewhat common occurence in the days when a lot of people shot on glass, so I'm hoping some of that knowledge might be available here.
If you have "only" 10 pieces to worry about, I would try sandwiching them between two negative carrier glasses of the same size as the neg without using glue, which will not have the same refractive index as the plate and I feel is likely to show. By butting the glass pieces snugly up against each other, there is a chance the break lines will not show, or at least should be fairly faint and easy to retouch. A slight (if messy) refinement to this process would be to contain the broken negative within a film of glycerine, which does have the same refractive index as the plate (standard technique for printing badly scratched negatives).
I second David's suggestions, only add that I would contact dupe it to an interpositive and lay a very thin layer of mylar in between the broken neg and the new film to protect the dupe interpositive.
That way, you could pour the glycerin on the broken plate and let the bubbles settle out.
Wonder if you need to add anything to the glycerin to keep the emulsion from stripping off?
Check with the alternate process printers here for sources for the mylar; I think they use it to protect their large copy dupe negs used for contact printing.
Good luck! Let us know what you do and you fare...