The term petrol and gasoline in a 1957 translation from Gauthier's German manual surely refers to the automotive fuels. the English term was "white spirit" otherwise.
At that time, petrol (as I recall, both grades) contained tetra-ethyl-lead plus other additives including upper cylinder lubricants.
I grew up in my father's auto dealership/workshop and to clean things including small parts they used half/half petrol/kerosine in a high air pressure spray gun.
Flammable and a health hazard (although those guys lived long ! ) it sure got the parts clean and probably left some lube on the surface.
I haven't opened the Prontor SVS here but from what I can see it is not up to the quality of the Graflex Wollensak ones here.
Early on in the disassembly process, I am proceeding carefully. This job WILL turn out correctly. With some previous study of the exploded diagrams on this one, the manufacturer was so kind as to have made them. It's actually step numbered. Adding to this, I laid the slightly disassembled shutter face down on the scanner, brought it into Photoshop and re-sized it for a full-sheet output on 8 1/2 x 11 10pt C1S in Indesign and ran it to the color copier. Now I have a big full-color blow-up of the shutter, and from there, it is simply a matter of pulling parts and laying them on shop rags in order. Simple as pie.
I can do this, and it WILL turn out right.
I detest using pure Naphtha or Liter fluid in a shutter. Many shutters have rubber and/or plastic parts that will be damaged by these solvents. 90% Isopropyl Alcohol works well and one of the best cleaners on the market is 60% alcohol 40% Naphtha.I just stumbled across this old thread looking for a Rapax service manual and to me, it reads like propaganda for a shutter repair guild.
........ every speed on it is nearly exactly 1/2 as fast as the dial says. That means whatever film you thought was ASA 100, is really ASA 50.
Thanks for the tips! I've yet to run into a problem with the naphtha, but I think I'll switch to the 60/40 mix you suggested for future use. Usually, if there are paper or plastic iris blades or shutters, I remove them first. The iris blades can be a pain to reinstall, but if you've got patience and some tweezers, it's can be done. And subsequent times are no where near as bad.I detest using pure Naphtha or Liter fluid in a shutter. Many shutters have rubber and/or plastic parts that will be damaged by these solvents. 90% Isopropyl Alcohol works well and one of the best cleaners on the market is 60% alcohol 40% Naphtha.
Now, a Graphex is a Rapax rebadged and the parts are rotated 90° on the Graphex ie the mount alignment pin will be 90° off from the Graphex.
The #1 assembly instructions are out of sequence but following the #2 assembly skipping the parts/steps not used on the #1 will get it assembled correctly.
A ultrasonic cleaner for jewelry with 90% alcohol will clean as well as Naphtha. Repeated cycles will cause the alcohol to get hot and may cause the finish to peel off.
I wish I could think up a better title to this thread to get it to show up in the most internet searches on the subject of old, sluggish shutters. You know--the old lighter fluid trick; naptha, paint thinner, or your favorite potion. Well I have news for you: say you've done the lighter fluid trick and have got your shutter nice and snappy again, and you're happy.
Truth is, NOT A CHANCE. It's nowhere near accurate, I promise you. And if you go off and start your film speed and development testing based on that shutter, and reporting your results on these forums, then you're totally polluting the information supply. And your tests will be so fouled up, a good actual photograph will be 75% luck.
I performed an experiment and sat here for hours testing press and view camera shutters, and you won't believe how far off most of them are. Of note, I've got a Compur here for a 135 Schneider from a Graphic Special. Absolute mint, never-used condition. And every speed on it is nearly exactly 1/2 as fast as the dial says. That means whatever film you thought was ASA 100, is really ASA 50.
The moral is, to either make a shutter tester from the photodiode of an old computer mouse and find out what your speeds are, so you can paste a chart on the camera, or send the lens off for a proper CLA.
Good luck.
Good ole shade tree corner cuttin'. Try that in a professional repair shop and they will kick you out the door.I have cleaned quite a few shutters over the years with Naptha/Coleman Stove Fuel. Put it in a Tupperware type container and soak the shutter with a lid on it. Shake it occasionally and you would be amazed at the junk that comes out of the shutter.
Run it in a professional setting of 50 to 100 trip cycles a day and you might be surprised at how fast it slows down or dies.I have a Compur shutter that I bought with a Tessar from the 30s that I cleaned probably 20 years ago and it still works fine. It now has a 300mm Rodenstock APO Ronar in it. No problems.
https://graflex.org/helpboard/viewtopic.php?t=6105 source from an online electronics supply since Radio Shack has all but bit the dust. I have tested 1/1000 shutters with the tester I built before I started that thread. Film testing verified the tester to be accurate (18% gray card used for density verification).What is a good non-professional and reasonably accurate shutter-speed checker or should I ask does/did anyone make one that comes up used from time to time?
No, it will only give it a good chance to. Springs are the only source of power in a shutter and they weaken with use. Wear only accounts for 15% to 20% of speed loss in most clean smooth running shutters the rest is spring tension loss until wear has increased to a significant level to produce sufficient drag. I do not know the limit where wear becomes the factor. Shutters like the Compur/Synchro Compur were built with tight tolerances, probably 1% to 3% depending on the machining of the day so an increase in play due to wear at 5% to 10% increase in bushing diameter/out of round pivot pins will likely cause speed slow down some.another question, are you sure that a CLA will assure you of accurate shutter speeds? Wouldn't an overhaul be better?
According to my shutter tester, this is not true for some of my cameras. I have an Icarette Vest Pocket from the 20ies with a Compur shutter. Fastest nominal speed is 1/300. If I measure what I would call the effective exposure at full aperture the speed varies from around 1/250 to 1/350. At a small aperture, however, the time may be slower than 1/200...
Shutters in old cameras are always off, always too slow, at high speeds typically by half a stop, often even more. Expect a leaf shutter at 1/500 to be more like 1/350.
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