J-9 exterior finish blemishes

[Bill58]

I just got a nice J-9 from Yuri, but it has some light rust-coloring that almost looks like paint (no pitting) in the grooves of the focusing and aperature rings and general cloudiness/ dullness on the barrel. Is this rust and can it be removed? How? Can I use Flitz on the barrel, since I think it's aluminum?

 

[clintock]

That is shellac! I think they must have used it as a preservative. I tried polishing it off in vain for hours then I thought- man that sure does look like shellac, and tried some alcohol, and it wipes right off. I mean I put the alcohol on a rag, and used the rag with the alcohol on it to dissolve the shellac.😛

It takes several rags or paper towels with alcohol to get it off, since the shellac turns back solid as soon as the alcohol evaporates, but it's easy. Just don't use so much on the rag that it flows into the insides of the lens!

Then the polish works properly.. so long as it's a polish that states it is for use on aluminum.

 

[Bill58]

Ahhhhha--that's what it is! Thanks, I'll try your advice. Flitz is OK on Aluminum, so I'll use it too and let you know.

Bill

 

[physiognomy]

Bill, I'd be interested to know whether you thought the lens still needed polishing after removing the shellac... I have thought about removing it from my J-9 & turret finder, but don't want them to be super shiny.

Peter

 

[cameosis]

That is shellac! I think they must have used it as a preservative. I tried polishing it off in vain for hours then I thought- man that sure does look like shellac, and tried some alcohol, and it wipes right off.

i bet it was wodka! 😀
what a nice slip, hehe.

 

[Bill58]

Bill, I'd be interested to know whether you thought the lens still needed polishing after removing the shellac... I have thought about removing it from my J-9 & turret finder, but don't want them to be super shiny.

Peter

Peter:

I just finished my project--using a soybean based paint remover to remove the shellac, then the Flitz. 'Looks great w/o appearing too shiny. The only problem now is the engraving for the F-stops are thin and not very deep, so not too prominent. I tried the black shellac stick I had from micro-tools but not much improvement.

Bill

 

[ZorkiKat]

It's actually lacquer. The 'white' lenses (no real chrome found in the barrel finishes) really had aluminium bodies finished with a clear coat of lacquer. Think of this to be similar to the black barrel lenses, only that the paint is clear. The coat protects the aluminium. Worn white lenses which have lost their lacquer coats often show lots of tarnish and pitting.

Removing the original lacquer coat totally without refinishing would likely be disastrous to the lens barrel. The stripped barrel would look nice and snappy for some time, but atmospheric pollutants, and salt, oil, and acid from sweat (contaminants introduced by the hand) will soon take its toll on the naked aluminium. Proof of this would be white Jupiters which have lost their coats - got a J-12 in such a condition, and it never seems to be able to shed the whitish powdery grime that seems to grow on its exposed skin.

 

[clintock]

Perhaps some lenses were coated with lacquer instead of shellac, but I am quite sure my chrome J9 was coated with shellac instead. Lacquer does not dissolve in alcohol, at least not as instantly as the amber coating of my 'new' 1953 J9 did.
I did try lacquer thinner as well, but only the alcohol worked well.
I agree that any un-protected aluminum surface will be more subject to corrosion than a coated one, but the shellac on my lens was not appied in a way that made me think the makers intended it to be a finish, more a storage preservative it seems.