cleaning gunk off the aperature blades

[John D Gerndt]

Hello. I just got a nice 10x12 B&L 1c which I guess is from the early teens of the 20th century. The glass is fine but the aperature is very sticky, hard to turn. I can see and feel the gum on the top side of the aperature blaces (camera side is cleaner) but I am unsure as to what to clean the blades with. Checking the previous threads leaves me worried about using the wrong type of solvent.

Does anyone know what those blades are made of and what will clean them safely?

Help*

[Paul Fitzgerald]

Hi John,

a B&L barrel lens can have either vulcanized rubber or metal foil blades and taking it apart to clean can be a bother. B&L are different than most barrels, it may be better to send it out for service.

If you're brave:

unscrew both lens cells and remove;

pull the front cover straight forward and off. this may require heating to loosen the grease;

turn the aperture ring full open to align the slot with the locater stub for the front cover and pull straight forward and off;

you can clean the grease off with naptha on a rag;

the stub that comes out of the barrel for the aperture ring to engage is the problem, its a screw that was put in and cut off. see if the blades will turn without futher disassembly;

if it needs futher disassembly, put it back together and send it out to a pro.

Hope it's a help

[Mike Kovacs]

I don't know about vulcanized rubber, but some old cameras have plastic or paper aperture blades that are dissolved with naptha (lighter fluid). Take great care!

[Dan Fromm]

I've bought two ancient B&L Tessars, both IIbs and both in barrel, with the same problem. It didn't live in the diaphragm blades, appearances notwithstanding, it lived in the space between the barrel and the rotating ring that engages the diaphragm actuator. Dismantling the barrel and cleaning there as Paul recommended solved the problems. Do that first.

Les Newcomer, who's a moderator on the www.graflex.org help board, was kind enough to send me some digital images of the process. If you'll send me your e-mail address, I'll be happy to send 'em to you.

Mike, barrels aren't always shutters. My two IIbs diaphragm blades seem to be metal.

Cheers,