Seized lens? C.P. Goerz Rapid Paraplanat II

[Rafan]

Hello everyone,

I've just got my hands on a pretty decent Goerz Rapid Paraplanat II which I'm eager to test but it has a major problem I can't figure out how to solve: the diaphragm ring doesn't turn...

I took the only screw there is out in order to try to disassemble the lens and clean her up but there is no moving whatsoever of anything... I'm getting to the point in which I believe it's seized or something like that...

The camera, lens and accesories have had little use and have been taken care of but this problem has taken me to a sudden stop...

Any help would be great. Thanks!

[Gary Beasley]

Probably a bit of corrosion and dirt in the aperture ring. A drop of penetrating oil at the rings contact point to the barrel, use the stuff sparingly, and try to work it. If it doesnt break loose in a reasonable fashion it should be taken to a professional.

[Rafan]

Thanks Gary. Will try with what you say (at least it works with my motorcycle...) but it's quite solid so let's see...

[Gary Beasley]

You dont want so much it gets on the diaphragm blades, so go easy with the oil. If it does break loose you may be able to finish the disassembly and do a proper cleaning.

[Rafan]

Tried and couldn't get it to move... I've been reading about using liquid fuel so might as well give that a try and/or cold...

I guess it might be, by what I've read, old waxy lubricant with dirt and grit as I neither can open the front or back to reach the crystal elements.

[Paul Ron]

put it in the sun to warm it a bit... the old crud may soften enough to work it.

[Rafan]

Thanks Paul. As soon as the sun comes out (pretty rainy sround here) I'll give it a go; in the meantime I got kyself some lighter fluid.

[Gary Beasley]

A hair dryer may do the job to heat it.

[Rafan]

Well, I'm happy to say I managed to loosen the apertura ring and the diaphragm works smoothly and perfectly. Just as a recap in case it's of help to anyone, this is what I did:

Yesterday night (around 22:00) I put some penetrating oil all around the ring using a toothpick, drop by drop.
Today at 08:00 it was the same as yesterday.
At around 15:00 I put some drops of liquid fuel (brand. Clipper, same as Zippo) all around the ring with the help of a q-tip, and with the same q-tip I let some of the fluid get inside the screw hole. After two or three tries it started to move and I was able to unscrew the ring. I cleaned the threads, reassembled and it's a joy to use now...

Next step is trying to take off the front and back elements in order to clean the lenses (a slight bit of white fungus and finger prints inside). Started by putting some penetrating oil all around and will see how it goes from there...

I'll keep you informed!

[Gary Beasley]

Since the screw is out have you tried tapping the ring towards the back of the lens to see if it will slip off the barrel?