How is a shutter cleaned?greenspun.com : LUSENET : Large format photography : One Thread
I am just starting large format photography with a Bender 4x5 kit that is now complete. I am waiting for a lens to arrive but have a Kodak Recomar 33 with a Kodak Anastigmat 135mm f4.5 in a Compur shutter.
The lens is in excellent shape and I mounted it on the Bender tonight. I get full coverage and it appears that the lens is useable but for a shutter that is woefully out of time. The shutter is immaculate inside and it appears that the sluggishness of the shutter is hardening lubricant. I have excellent mechanical skills and would like to get the shutter functional rather than simple use it in B for night photography.
Is a solvent used to clean shutters? Are there any hints about cleaning and retiming shutters? Any help you might have is appreciated.
-- Dennis Daigger (email@example.com), July 27, 1999
Hi Dennis, i'll fill you in on what i've done, but i'm not a shutter repair person; so you are forewarned, right! i don't think i've re- timed a shutter. what i've done is just cleaned them, and then you find someone with a shutter speed tester, and you have them give you the corrected times, tape that to the lens board and go from there, or you can just adjust your development to how your negatives work. you can tell i'm a big spender with photo-gear right. what i think is that it is very important that the shutter blades are "clean" and i also think that it is important that the races that the blade stuff rotates or flinches in is "clean" and so I polish all of the above. i cleaned them with soap and water and dried them, and then polished them with very fine steel wool and then with cotton until they are slick to the touch. i think the slickness for the speed comes from dissimilar metals touching. You do not put oil on any of this stuff!!! i just cleaned an polished everything. i didn't take any of the gear trains apart. i cleaned them with tooth brush and a solvent. then i treated heavy sliding parts with white grease. and i used a very thin oil, sparingly, on the ends of the shafts of the escapments which rock back and forth, and don't put oil on the gear teeth associated with that train. i found the oil in a hobby shop where they have stuff for model trains and airplanes; it comes in a little thing kind of like a pen whith a needle on the end, and i've seen where someone said to put the oil on a tooth pick and then on the end of the shaft. sometimes i've found that people have worked on the shutter and put oil where it doesn't belong, and this just causes strange behavior. a lot of the pivots are made to function dry with gravity. you just have to sort out which is which. for the most part, only a tiny amount of oil on the ends of the shafts of the escapments. but for the rest, polish the moving blades and parts of the shutter, and then leave them dry and clean. this is how i did my dial set compur which must be over fifty years old. i don't know if a knowledgeable tech does it like this, so you are forewarned. you won't believe how impossible it is to find one of those little screws in a shag carpet either. good luck.
-- david clark (firstname.lastname@example.org), July 28, 1999.
Better yet...Get in touch with Steve Grimes http://www.skgrimes.com/index.htm#nav
-- C MATTER (email@example.com), July 28, 1999.
I too would let a pro do it. Steve Grimes has a good reputation, and a CLA is not expensive. I destroyed a 100/6.3 WF Ektar by trying to do it myself. (Opening it up caused many small springs to fly out! Wonder where they go?).
-- Ron Shaw (firstname.lastname@example.org), July 28, 1999.
I am also not a professional repairer, but a trick that those folks use is plain old lighter fluid. Try squirting lighter fluid directly into any and all lens openings and cracks while working the shutter, Don't get concerned if the shutter hangs up while the inside of the lens is still wet, it will ususally begin working once the lighter fluid evaporates. This has worked for me on several lenses, and has done no harm to a lens with a mechanical defect (as opposed to old grease and dirt) causing the malfunction. I do not believe in the use of any type of lubricant either, especially stuff like WD40
-- Jim Mcdonough (email@example.com), July 28, 1999.
I thought I'd pass on my experience with cleaning this shutter after hearing from you folks.
I used lighter fluid (which I think is nothing more than naptha which is cheaper in small cans) as suggested and that worked great. I waited until the next day to lubricate the shutter, allowing adequate time to fully dry the solvent. In the meantime, searching Alta Vista for "compur" I found someone that gave specific instructions for disassembly of this particular Compur. The instructions worked great and I was able to carefully lubricate the levers, wheels, etc. I used Boeshield T-9 which is one of the finest handgun lubs I have ever used.
The shutter is beautifully crisp and smooth now and I think will work fine.
To those of you that advised to send it out for cleaning, I also checked Mr. Grimes site and was amazed at the information available there. If I ever own an expensive shutter that needs repair, I know where it will go.
And the follow-up question is about how to time the shutter. Now that I understand that the numbers on the shutter speed are not fractions of a second, other than a lot of trial and error and wasted film, how do I determine the times of each mark?
Thanks to each of you for your responses.
-- Dennis Daigger (firstname.lastname@example.org), July 30, 1999.
Dennis, Don't worry about adjusting the speeds on your older shutter, it's not worth the effort. Simply drop them by your local camera repair shop (or anyone who has a shutter tester) and have them test the shutter and give you the actual speed in milliseconds for each marked speed. The accepted method is to do the test at a medium aperture, say f16 or f22 (as a compromise as the effective shutter speed varies with aperture size) and to make several tests at each setting to be able to come up with an average value. Also make sure your tech fires the shutter in a vertical and not a horizontal position if possible as this can also affect shutter speeds in older shutters. Then, when you have the average value in milliseconds for each setting you can easily convert these to fractions of a second. For speeds between the standard marked speeds, I round them to the nearest 1/3 stop and mark them as values plus or minus the standard settings. The ISO number scale, which corresponds roughly to the shutter speed scale can be helpful here, for example, 1/80th of a second would be 1/60+ (where the plus sign denotes a faster shutter speed), 1/100 would be 1/125- etc. This gets you into the 1/3-stop accuracy ballpark and agrees with the markings on most light meters. You could also use 1/2 stop increments if you like. Hope this helps, Regards, ;^D)
-- Doremus Scudder (ScudderLandreth@compuserve.com), August 02, 1999.