Bubbles on Top Plate - M6

[love4leica]

Any idea what causes this? Whats the cure? Is this an indication that something

else might be wrong with the camera body as well? Many thanks.<div></div>

[mikep]

Hs this been re-painted? or under gone a major repair since new?

[35mmdelux]

generally base metal not properly prepared.

[vinay_patel]

The way it was explained to me on one of my visits to the Leica factory was that there is an acid bath in-between the plating layers and at one point in time there was a problem neutralising and it resulted in subdural gassing. I can't say I've ever seen it on a silver finish though, but it was very prevalent on black M6 bodies in the 1,77x,xxx-1,78x,xxx-range and also the R4, both made around the same time in the mid-to-late 80s. What's the serial # if I may ask?

[icuneko]

<Any idea what causes this?> Ah ... global warming? ;)

[ronald_moravec1]

Pray it is not the zink metal corroding. Brass is/was best as always.

 

This is like Rolls Royce putting cheap tires on their cars.

[keirst]

It's Zinc oxidation under the chrome plate, as others have said. Moisture and oxygen are

probably getting under the plating, through small flaws. Another way this could occur is by

electrolysis if there is a short circuit to the case from the electronics of the meter or battery.

This second possibility would also cause batteries to be consumed quickly.

 

With either cause, the Zinc oxidizes and the corrosion lifts the plating up like bubbles. The

top plate would need to be replaced to eliminate the problem, and if batteries don't last long

the camera electronics should be checked. Only M6 cameras used the Zinc top plates. Other

Leica Ms have brass tops which don't corrode this way.

[cebes_johnson]

Hello

 

What Vinay states above is very interesting and something I did not know. This is most certainly your answer then, however, I feel the need to confuse things a bit.

 

A bad circuit or grounding to the body in time can create (due to a continuous electrical charge running in effect through/to the body) paint to bubble and/or flake off.

 

This happens to other similar cameras in past eras and was an interesting comment while working with a long time camera repair person when the topic came up.

 

Having done electronics of all sorts restoring English cars, it certainly made sense!

 

Again, take it fwiw, but it is something that apparently happened with other non-Leica cameras in the past. I thought it was interesting and worth mentioning.

 

 

regards

 

Paul

[love4leica]

Vinay, the serial # is 201XXXX which dates it to 1994. Can you give any more info, please? To buy or not to buy? The price is very very attractive. Thank you

[Bill Blackwell Images]

What Vinay and Steven said.

 

All standard production M6 topcovers are molded form zinc alloy and as production proceeded, Leica figured out what worked. Your camera is likely an early Wetzlar model with engraving on the topcover (something like "Ernst Leitz Wetzlar GMBH") with a "Leitz" red dot on the front.

 

Early M6 cameras often have the "blistering" condition you describe. I am sorry to report the only "fix" is a new topcover. However, it took ~20 years to get that way and, if you can live with it, the condition may not get any worse than it is right now.

[Bill Blackwell Images]

Afzal:

 

I was replying before you posted your last message. I have not seen many examples of M6 cameras in a vintage as late as yours with the "blistering" condition, but the zinc alloy still remains. Even so, the condition is not all that common - especially in the later production models (Leica got it right most of the time), so unfortunately, yours is one of the unlucky ones.

 

I would chat with Don Goldberg "DAG" about having it replaced.

 

Regards, Bill

[Bill Blackwell Images]

BTW, it makes no difference if the camera is black or silver. The issue is in the zinc base metal, not the plating.

[jose_suarez1]

About 7 Years ago B&H Photo and Video (used Dept.)

had a Black M6 w/ one year Leica USA Warranty (Demo), that the salesperson described as a bad paint job - it looked like a Leica with chicken pox.

I forgot, the price was approx. $1800 + tax

 

Leica USA did sell this demo, and refurbisher items now and then.

 

Jose Suarez, Spain

[35mmdelux]

What you show are few bubbles. Based on this, I'd buy it on attractive price.

[aplumpton]

As one gets older, superficial flaws on one's face are evident. The interior rests (or

should rest) the same. Same for your camera. As a metallurgist in one of my prior

lifetimes, I would say they appear to be only superficial and caused by one of the

reasons already given. The top plate is thick and any harmful gases will have leaked

to the ozone layer and not inside. Look upon the spots as "marques de noblesse" or

beauty spots, and profit from the good price (assuming of course that all else is

perfect). I can guarantee 100% that they won't appear in your photos.

[fred_c1]

Late M4-Ps also had zinc top plates, not just M6.

[Bill Blackwell Images]

"Late M4-Ps also had zinc top plates, not just M6."

 

Actually, yes. A fair number of the last M4-P cameras (perhaps 5,200 units) had zinc top covers - they are evidenced by flat M6 style RF windows. Ironically, I have never seen an M4-P (with a zinc top cover) that blistered.

 

BTW, after studying the picture you posted above more carefully, I have decided I would do nothing. The condition on your camera in very minor (I have seen much, much worse).

[torben_daltoft]

Anyone seen this on an M7 (Betriebsk.)?

[Bill Blackwell Images]

"Anyone seen this on an M7 (Betriebsk.)?"

 

No. And you won't either - all M7 top covers are made of brass.

[alun]

I have an M6 0.58 from about 2000 bought used. When I took delivery it still had the

plastic protector on the baseplate. When I peeled off the protector I could see that around

the very edge of the baseplate there was some flaking, rather as if one of the coats of

black chrome hadn't 'taken'. This had a dusty feel to the touch. I just scraped it away. The

loss isn't down to the bare zinc and isn't particularly noticeable either. Just one of those

things, I thought -- something hadn't gone quite right in the coating process.

 

The imperfections on your silver chrome are minute -- I wouldn't give it another moment's

thought, personally.

 

--alun

[love4leica]

This forum is a bank of knowledge and information. Thank you to everybody for your input. Regards & best wishes. Afzal

[Bill Blackwell Images]

"When I took delivery it still had the plastic protector on the baseplate... The loss isn't down to the bare zinc and isn't particularly noticeable either."

 

The top cover on most M6TTL cameras is zinc alloy, but not the base plate. Leica considered zinc for the base plate when the M6 went into production, but ultimately decided the metal wasn't strong enough on the latch side.

 

If your camera is black chrome, there is a thin layer of a zinc alloy between the black chrome and brass. Every Leica M base plate ever produced has been brass.

[stuart_vu]

My silver chrome R6.2 with serial number: 248XXXX does has some bubbles on the top-plate. Any taker?

[william_e._thompson]

"The top cover on most M6TTL cameras is zinc alloy,"

 

I have an old M4-P and a M4-P with M6 windows that was made at the same time the M6

came out. I am pretty sure the latest M4-P has an M6 top plate made of zinc but is the old

M4-P brass or zinc?

 

Thanks

[ray .]

I've seen some M6TTL's with this issue on the top plate. As I post there are two for sale on ebay,

one of which is much more extensive than what shows on the OP's pic.