Hi !
well, in fact I tried a couple of them. The first one was simple acrylic black paint. It seemed to fix the problem firstly, but after a couple of days, the paint looses its flexibility and the pinholes apeear again.
Secondly, I tried the black electrician tape method from Roland and Caroline (.co.uk I think). It's an ugly method but if done carefully it seems to fix the problem better (I checked the inside of the bellows under an halogen ultra bright light).
But (and here begins the sad part of the story), I couldn't resist the temptation and started the lens clean job last Sunday. Man, I hope I didn't. The back element had serious coating damage after all, and the cleaning process was a nightmare. Even with the smoothest clean I could do using lens cleaner and q-tips all the coating came apart and the lens ended badly scratched... sigh... :_(
Before knowing the results from the back lens (yes, there's still more), I followed the instructions of a website about cleaning the central element with the shutter open at B setting. This time the lens was easily cleaned and results were good, no damage, no scratches. I supose the central element was in better shape, BUT, as it seems it was 'my lucky day', some cleaning fluid found its way to the diaphragm blades, where lots of hidden rust were expecting an oportunity to be alive again, so now the blades are dirty and sticky...
To sum up, a gathering of bad decisions and some hidden surprises inside the camera ruined my first restoration attempt :_(
Maybe if someday I find a good lens/shutter assembly from a body-dead Isolette I could build a frankenstein, but meanwhile I think the nice Agfa is going to be a shelf item, sigh...
Anyway, as now I can't lose anything, I'll try the other methods on the bellows as an experiment. As I said you, the tape method seems to work, but is ugly, and makes bellows thicker and sticky.
The black silicon method seems good, at first sight, so maybe you could give it a try. The problem is that it seems irreversible... Anyway, now that I can't expect decent pictures from the camera, I recognize I've lost some interest. I supose I can't blame myself eternally, but for sure I will do it for some more days...
Good luck with your bellows, or at least better luck than me !
Cheers !
Oscar (sorrowful

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