Zeiss pimples

This may, or may not have been covered, but here goes. I always spend a few minutes perusing the classic cameras

on the bay. What is the cause of the bumps that always seem to show up under the leather coverings on an

otherwise pristene old german camera?

Dissimilar metals corrosion,

I don't agree with the last post. Corrosion due to contact of different metals needs some acid. Also, this corrosion usually does NOT increase the dimensions of the metal parts in question. I think the "Zeiss bumps" (which can be found on other camera brands as well) are rather due to corrosion of brass rivets. Copper and brass corrode quite easily in the presence of water. The corrosion products will need more space and thus will lift the leatherette.

 

I think the only cure would be taking off the leatherette, grinding off the corrosion products and cover the rivets with some water-resistant paint.

Please don't forget that Tannic Acid is used on leather also and the remmanents of that with the metal might cause a reaction and corrode the metal.

As Winfried says, it's almost always corrosion of brass rivets; if you peel back the leatherette on a 1930s-1950s Zeiss camera with the "bumps", you'll find little domes of bright green crud on top of the brass, and nowhere else.

 

And, as already mentioned, it doesn't just affect Zeiss cameras - old Speed Graphics frequently have this problem on the bed/door, among many others.

Winfried has got it. It's almost always caused by the creation of what is called verdigris*

 

*[verdigris |ˈvərdəˌgrēs; -ˌgris; -ˌgrē|-- a bright bluish-green encrustation or patina formed on copper or brass by atmospheric oxidation, consisting of basic copper carbonate.

I should have added that on Zeiss and other cameras it is often soft enough that it can be scraped off with the

fingernail. It has a kind of "greasy" texture. One solution is to put a little non-chemically active lacquer on

the brass after cleaning it and before replacing the leatherette.

I would tend to agree with Charles and Jose, all the cameras on which I have encountered this problem have had real leather coverings. Cameras with fabric or plastic based coverings do not have the bumps even if they have the brass rivets, perhaps because they have no tannic acid in the fabric coverings. It may be related to the type of glue used by Zeiss, Balda, Welta (the usual suspects), their fabric covered models do not seem to have the bump problem though, but they may have used different glues for leather.

Many of the postwar east German cameras with Zeiss (Jena, that is) bumps, were never anywhere near a real leather cover. They were covered with a distinctive fake leather. It's verdigris, folks. Simple chemistry.

Older Kodaks are mighty subject to it as well. Commonly known as "Zeiss bumps".

I've never personally seen these bumps on any camera that didn't have real leather covering; not to say it doesn't happen, but not in my experience. The green crud, while it certainly comes from the brass rivets and contains copper oxide, is soft as JDM states and can be easily scraped off, leaving bright brass underneath with nothing that I would characterize as visible corrosion on the metal. If you get the metal very clean and coat it with a durable lacquer on and around the rivets, you should be able to significantly delay if not prevent the recurrence of Zeiss bumps after reassembly.

I've seen sellers pointing to these bumps as a sign of genuinuity. As if to imply one should spend more money

for those cameras that have this. As stated it's just chemistry. I've never removed a leatherette yet

for this reason or to clean it it, because you don't see the "vertgris" (sp?), but I've genty scraped it off.

It does come back despite good "dry" storage. (Graflex Jr) I've recently aquired a Zeiss Ikon 520A. In many places

the vertigris can be seen. After cleaning, what "laq" would be appropriate to stop the action? In this case I'm referring to the exterior points, not something that would be "hidden" by the leatherette.

I think Winfried is correct and I was wrong. Leather is a rather porous material and maybe a good leather sealer would slow down the process.

On the exterior where it would show, clear nail polish would probably work fine. I'd test any nail polish for

interaction with the leatherette+adhesive in places that are hidden, perhaps on a nice old Ossie (DDR camera) of

low value before you try this on your original Contax II. The trouble is that it would take a long time to show

up, if there were a problem. I have never personally tried the "lac" solution, which why I suggest caution. I

just don't know how chemically neutral fingernail polish, for example, really is. Any chemists out there?

 

Here, for those of you who wonder what the brass connectors look like "nude" is a naked Exakta. Unfortunately I

don't have it with the verdigris in place, but you can still see a little of it at the seam at the left red

arrow. The right red arrow is one of the brass 'tacks'.<div></div>

Hi, Ed -

 

Some excellent answers and suggestions here, the best info I have seen on the subject yet. I have experienced "Zeiss Bumps" on several cameras, from Retina IIa, Rolleicord V, Rolleiflex E2, etc. I keep a good leather polish/cream on the leathers, (or vinyl, whatever other cover material might be used.) For many years I have been using Meltonian, black on the body covers, cognac on the brown cases. The leather stays well protected and supple, never yet experiencing the characteristic "cracking" where the bends and flex folds are placed on cases.

 

Interestingly, with German camera's that I purchased new, starting in the fifties, keeping the leathers always really clean, have never shown the corrosion creating the bumps. My Rolleicord V and Rolleiflex E that I purchased new remain free of the bumps to this day. When regularly serviced the side covers must be removed for access to internals, and show no signs of the bright green material on screw heads. Perhaps keeping the covers well sealed with polish has prevented air from reaching them? Just my guess.

 

My Rolleiflex E2, (only in one spot,) Rolleicord II, Rolleicord V and Retina IIa cameras that I acquired used, ALL had the mentioned corrosion and bumps, but easily cleaned and recovered, never showing up again after several years. I did the Retina IIa myself, using acetone to clean the screws after removal of the corrosion, long air dry, then clear nail polish with long dry time again. Used recommended adhesive for light coat on both surfaces, replaced cover and voila, never showed up again.

 

A technician told me my Rolleicord Vb has vinyl covers, that could be why it has never shown bumps, and I bought it used also. That could indicate that real leather does indeed react, to the brass screws underneath. Just another guess.

 

I have to wonder if storage conditions in home might be a factor, I try to ensure clean, dry, even temperature atmosphere. My cabinet is not the air pressure sealed type, but well protected from moisture being able to penetrate. I keep small dessicant (sp)? packet inside, replacing regularly. I live in Western central Oregon, so neither extreme cold, heat or humidity is a factor for me. Likely a considerable potential for damage if living in areas with atmospherics other than those I experience.

 

The remark of the corrosion feeling waxy/greasy is right on the mark, and after removal I find no sign of major metal pitting on screw or surrounding body panel surface. I don't think the corrosion I have seen would do any permanent damage to the camera, or spread to internals, but can continue to grow until cover is so distorted and stretched that a good refit is no longer possible.

 

To sum up, I think the corrosion I have seen was confined to the area immediately between the screw/rivet tops and the cover above, not spreading to areas below or adjacent to the screw sides. Quite an easy remedy, but best taken care of sooner, rather than later. If attempting to do yourself, care must be taken when removing cover for access. I start in the extreme corner nearest the bump, then using dental tools, NOT sharply pointed, I gently and slowly start lifting the corner. Once you have gotten a small area lifted it goes faster, lifting along the edge until you have gained access to the areas needing attention.

 

I have heard some say they use acetone or other solvents to loosen the glue, but I don't recommend that. It's really messy and I think too aggressive, you may end up with a really difficult area to resecure the cover to. Slow and steady lifting pressure does the trick every time, I have yet to puncture or otherwise damage a cover. It's mighty important to not damage covers, a tear or puncture does not enhance the appearance when reattached.

 

Thankfully bumps are a rather small problem, but often encountered. If you try a fix yourself you won't find it terribly dfficult, and it is quite satisfying to see a positive result following the procedure, as in "I did it myself." If any doubt as to your ability, leave it to a pro technician at next service.

 

I hope this may be of some help to Ed, or others that may be unsure of how serious, or how to repair.

 

Best of luck

 

Patrick

Never use acetone; it's simply too effective and aggressive a solvent. Maybe to remove old adhesive on metal, but even there with great caution. Naphtha is better if a solvent is needed.

My experience has been as Winfried and Richard describe. In my case, I removed the leather covering, as the 'Zeiss bumps' were extensive to an extent that made the camera unpleasant to hold, a difficult task as the leather was already in poor condition and damages, and the shellac (or whatever) adhesive resistant to the gentle organic solvents I was prepared to use. Underneath, but especially around the brass rivets, heavy oxidation was apparent. I cleaned it all off, and primed the bare metal. The camera now awaits a recovering, provided I can find an old leather-bound diary whose coat I intend to strip off for the purpose. It means of course that I lose the 'Zeiss Ikon' embossing on the old leather, but my intent on such renovation as I'm able to undertake is to give me a user camera, not a display piece.

You can do your own leather, but I do recommend either buying the raw materials or the kits for specific cameras from someone like http://www.cameraleather.com/ .

 

If you are a purist, you can find something very like the original cover from them, but if you are a "cameras gone wild" kind of person, you can do snakeskin or other exotic covers for a price.The kits come precut, and are easy to install if you can read and comprehend the instructions. the website shows some spectacular recovers.

 

I redid an Exakta in red kid leather after seeing another one on this site - it is Art Deco with a capital A. ( http://www.photo.net/classic-cameras-forum/00NSzV )

Alex: it took me some time to find this link from a Japanese camera site, showing good pictures of how to remove and put

back the leather on a Contax IIa (descriptions are in Japanese), showing also a unique way how to keep the Zeiss Ikon

logo on the camera back: cut the leather around it and leave it where it is - sounds a bit weird, but pictures are tempting.

Here's the link:

http://aki-asahi.net/store/html/contax-IIa/install/01_j.html

Talk about getting down to brass tacks.

 

"One solution is to put a little non-chemically active lacquer on the brass after cleaning it and before replacing the

leatherette".

 

Nail polish? Do they still sell clear laquer spray? One could spray some on a cardboard and gently apply it with a

brush. On cars we had special primers or treatments to seal off problems such as this.

 

I have seen ammunition, and cameras, left for long times in contact with leather, cases in the situation of the

cameras, and the green parts are evident in certain places, all the more reason not to store them in leather cases? I

have been lucky so far, it has been on the surface and wiped off with a soft rag, might use a microfiber cloth these

days kept for that purpose. A prime place was the plug in the back of SM Leicas.

 

Anyone using a particular product to keep old camera leather in good shape without doing any damage?

 

A lot of camera shops have several tins of shoe polish, next to the black markers of course. Lots flush shutters with

solvents rather than doing a proper cla, they seem to charge the same.

 

Good to have a forum such as this to find the good people.

 

I am thinking of recovering a Standard as the leather is really in pieces, too bad, it was a conversion with a low

number, but you can hardly pick it up without pieces of that think leather or whatever, breaking off, and it is 50%

gone. Paint is 90+ % and it works.

 

Leica bodies are aluminum? Brass rivits with Aluminum, Aluminum is a very reactive metal.

 

Regards, John