Asked before but got nowhere: Spotmatic battery cover

[AgX]

We should not overlook that penetrating oils have side effect: spread. Thus you easily cover parts you rather want to stay free of oil. And these oils only slowly evaporate.

Acetic acid though evaporates in little time. However it will settle again salts at other places it has dissolved before, even as other salt. So one may have cleaned a battery chamber perfectly but the same time may have brought hygroscopic salts even deeper into the innards, effecting in leakage current at high humidity. It also may have effect on surfaces cosmetically.

There is no golden potion...

 

[David Lyga]

runswithsizzers: The battery cap is metal, as is the bottom cover (which can easily be unscrewed). I would highly recommend that everyone apply a very thin layer of Vaseline onto those threads. This will obviate any roughness when inserting and removing these caps.

Many solutions have been offered. Will any work? I have to ponder all this.There should be an enforced law against leaving a battery in one of those close chambers for a long time. - David Lyga

 

[bdial]

runwithsizzers makes a good point, dealing with iron oxide, which is the usual problem with the fasteners that the penetrant products are intended for, is different than dealing with corrosion in other metals, such as the aluminum and brass that are the typical materials for our cameras. Yes, the cap and bottom cover are metal, but that's like observing that much of our DNA is shared by trees, the devil is in the details.

 

[BrianShaw]

Is the lubricating or penetration power of oil dependent on the type of metal? I agree that oxide/corrosion reduction may be, but if all that’s needing is to reduce the friction a bit...

I don’t know about the other products but Kroil is specifically formulated for both ferrous and nonferrous applications. My experience With it includes brass and pot-metal, and it can help separate parts that has “welded” itself together after decades of being torqued together. Maybe that’s why it costs more than the other penetrating oils????

 

[BrianShaw]

“There should be an enforced law against leaving a battery in one of those close chambers for a long time.”.

Amen, brother David... and there should be an enforced law that only dime sized tightening slots provided to ensure that the minimum amount of leverage can be used to avoid overtightening... slots that allow quarters just invite overtightening!

 

[resummerfield]

I successfully removed the battery cover from a very corroded Pentax Spotmatic once.

Remove the bottom cover, soak it in vinegar about 24 hours, then place the bottom cover in an ultra sonic cleaner with more vinegar for about an hour. Then embed the bottom cover in a piece of foam to distribute the high torque and use the nickel and pliers.

The first attempt only moved the cover a fraction of a mm, so I repeated the entire process (another 24 hours, etc). On the third try it did successfully unscrew. Any corroded area will have the chrome removed.

 

[Sirius Glass]

Once the cover has been removed, there are several anti-seize products that can be applied to the threads to prevent future problems.

Once I stopped for a repair in Las Vegas and the mechanic thought that he would do me a favor and put anti-seize on the spark plug threads. BIG MISTAKE! Anti-seize is an insulator, not a conductor and fifty miles down the road the engine started bucking like a bronco and not in a good way. Putting anti-seize on the battery cover could prevent the circuit from being complete, causing bigger problems.

 

[BradS]

Once I stopped for a repair in Las Vegas and the mechanic thought that he would do me a favor and put anti-seize on the spark plug threads. BIG MISTAKE! Anti-seize is an insulator, not a conductor and fifty miles down the road the engine started bucking like a bronco and not in a good way. Putting anti-seize on the battery cover could prevent the circuit from being complete, causing bigger problems.

good point but...
There is a special anti-seize goop for spark-plugs it is silver-grey and has some kind of conducting (metal ?) stuff in it.

 

[Helios 1984]

What about leaving the bottom plate in the freezer for 24h to crack the joint?

 

[Sirius Glass]

Make the cover plate only cold, while the rest of the camera is at room temperature. You want the cover plate to contract. Chilling everything will change nothing.

 

[Pioneer]

I was able to remove the battery cover cap off the a corroded Spottie. Vinegar and an ultra sonic cleaner did the trick for me as well. It did take a few days but it finally came apart. The cover looks pretty ugly but it does screw in and out now.

What I found weird was that the electrical contacts inside, though corroded, came clean with baking soda and I am still using the same contacts. I did have to take the wires off, trim them and then re-solder them to the contacts. Still working to this day.

I have a second one that had the same problem but when I got it apart the cover was too corroded to be re-used. Again, though the cover was so bad it was literally falling apart, the inside cleaned up very nicely and I picked up another battery cover off of e-bay. It does look a bit weird with a brand new cover with the area surrounding the cover badly discolored from the corrosion, but it works.

 

[runswithsizzers]

anti-seize

Once I stopped for a repair in Las Vegas and the mechanic thought that he would do me a favor and put anti-seize on the spark plug threads. BIG MISTAKE! Anti-seize is an insulator, not a conductor and fifty miles down the road the engine started bucking like a bronco and not in a good way. Putting anti-seize on the battery cover could prevent the circuit from being complete, causing bigger problems.

There are dozens of lubricants and anti-seize products advertised to be electically conductive. But even if not conductive, applying a thread lubricant should not prevent electical conductivity; when the parts are screwed together the grease is pushed aside and there will still be metal-to-metal contact. The grease which is pushed aside fills the air gaps, which reduces oxidation and corrosion (but not conductivity).

The use of anti-seize compounds on spark plug threads is somewhat controversial. Most spark plug manufacturers don't recommend using anti-seize compounds because special plating on the threads now makes it unnecessary. However, the special plating is for one time use, so if the spark plugs are removed, some mechanics say anti-seize should be used before they are reinstalled; see <this site>. According to naysayers, the main problem with using an anti-seize compound is that it lubricates the threads, so torque needs to be reduced by about 20%. If the lubricated threads are torqued to dry specifications, bad stuff can happen. The second problem, is when anti-seize gets carelessly slathered on the spark plug and it contaminates the electrode which can cause misfire. Maybe that is what happened to your car (?) I could not find any evidence that anti-seize compounds prevent the flow of electricity between threaded parts. And several articles claim some anti-seize compounds improve electrical conductivity <like this one>

Obviously, a camera battery compartment cover does not need an industrial strength anti-seize compound. I would try a light application of petroleum jelly, or just about any thin all-purpose grease, to the threads, only.

 

[David Lyga]

How about locally heating it with a small soldering iron ?

Remember, there is a battery in there. Is there a possibility for an explosion?

 

[Kodachromeguy]

It's been a long time since I owned a Spotmatic - can't remember if the battery cover is plated brass or steel or ? If it's non-ferrous, the electrical contact type cleaners might work better than the rust busters ??

Hi everyone, a 2020 Spotmatic update: I had some GAS and bought a Spotmatic II with a corroded mess on the bottom where the battery leaked. I cleaned the corrosion with steel wool, which left the cap bare and tarnished metal in the vicinity. The cap is definitely brass, as all the plating has come off. But the cap has welded to the bottom cover. I have tried penetrating oil, but no success yet. The slot has been chewed up by a previous owner who tried to remove it. Options:

1. Take the bottom off. Problem: the screw closest to the cap (next to the tripod screw) is tarnished and the head has been chewed up, so there is no grip for a screwdriver. Therefore, I can't remove the bottom unless I drill out the tiny screw. In reality, the bottom would stay on the camera quite securely even if this screw was missing.
2. Drill two holes in the cap. But, I do not have a lens retaining ring tool with the points, which I could use if I drilled the cap.
Any suggestions how to proceed next?

Surprising note: Other than the battery corrosion, this Spotmatic II body is in really good shape. Even the bumper foam at the mirror looks fine. All shutter speeds work, self-timer is fine, viewfinder clean and clear, and the flash synch works. I bought the body, 50mm f/1.4, and 28mm f/3.5 lenses all for $45. The 28 is pristine. My guess is this once belonged to a novice photographer who did not use the equipment very much. The clue comes from the braided banjo-style strap that was in the package. Recall how these were sold to novice photographers in the 1970s by big box and many camera stores.

 

[BradS]

Hi everyone, a 2020 Spotmatic update: I had some GAS and bought a Spotmatic II with a corroded mess on the bottom where the battery leaked. I cleaned the corrosion with steel wool, which left the cap bare and tarnished metal in the vicinity. The cap is definitely brass, as all the plating has come off. But the cap has welded to the bottom cover. I have tried penetrating oil, but no success yet. The slot has been chewed up by a previous owner who tried to remove it. Options:

1. Take the bottom off. Problem: the screw closest to the cap (next to the tripod screw) is tarnished and the head has been chewed up, so there is no grip for a screwdriver. Therefore, I can't remove the bottom unless I drill out the tiny screw. In reality, the bottom would stay on the camera quite securely even if this screw was missing.
2. Drill two holes in the cap. But, I do not have a lens retaining ring tool with the points, which I could use if I drilled the cap.
Any suggestions how to proceed next?

Surprising note: Other than the battery corrosion, this Spotmatic II body is in really good shape. Even the bumper foam at the mirror looks fine. All shutter speeds work, self-timer is fine, viewfinder clean and clear, and the flash synch works. I bought the body, 50mm f/1.4, and 28mm f/3.5 lenses all for $45. The 28 is pristine. My guess is this once belonged to a novice photographer who did not use the equipment very much. The clue comes from the braided banjo-style strap that was in the package. Recall how these were sold to novice photographers in the 1970s by big box and many camera stores.

I usually take the bottom off and soak the whole thing in vinegar for a day to two.
Once I drilled holes in the cap as in #2 and tried forcing the cap...which broke the whole batter compartment from the bottom cover. I never did that again.

I think I have a spare SPII bottom plate in decent condition if you want it.

 

[David Lyga]

I usually take the bottom off and soak the whole thing in vinegar for a day to two.
Once I drilled holes in the cap as in #2 and tried forcing the cap...which broke the whole batter compartment from the bottom cover. I never did that again.

I think I have a spare SPII bottom plate in decent condition if you want it.

Thank you, but I have several from previous, unsuccessful attempts at repair. I am not desperate over this, but was curious over such a seemingly simple task that is anything but.

In fact, I have, with one Spotmatic, done something that is downright sacrilegious. I purposely destroyed the actual battery chamber (from underneath the back cover). Then I took a pair of pliers and, engaging both front and back of the battery cover, opened it that way. Of course, I was then left with no battery compartment, but it was not too difficult to 'build one' of sorts after that bottom cover was put back onto the camera body. It works. - David Lyga

 

[Bill Burk]

Is it standard practice for you David Lyga, to remove the entire bottom? At that point you could hold the battery cover in a c-clamp and twist, couldn’t you?

 

[David Lyga]

Is it standard practice for you David Lyga, to remove the entire bottom? At that point you could hold the battery cover in a c-clamp and twist, couldn’t you?

I almost always remove bottom covers in order to get accumulated dust out. It is a very easy thing to do.

When you have removed the bottom cover and have also destroyed the battery compartment, you then take a pair of pliers and one side of the pliers holds the top of the battery cap and the other holds the bottom. In that configuration, it can be readily unscrewed. Of course the actual battery compartment is destroyed, but that is not as bad as first seems. You still have the bottom terminal on the camera body and all you need to do is be able to connect the other battery terminal to metal in the bottom cover. That is not too difficult, and outwardly, there is no cosmetic difference to the camera body. - David Lyga

 

[BobD]

I have successfully used the vinegar bath + nickel-in-pliers method. Of course, after I finally got it off I found that the meter didn't work anyway.

 

[BradS]

I have successfully used the vinegar bath + nickel-in-pliers method. Of course, after I finally got it off I found that the meter didn't work anyway.

Yup. Been there. Done that.
still it’s good to get to the source of the decay.

 

[waynecrider]

With anything that has been corroded shut I use Supco oil. Supco is a product used in the air conditioning industry to prevent seizures in compressors. It has never not worked. It will require a little work tho but with a good hour soak one should be able to move the cover back and forth and eventually get it off. Supco is also fantastic for rusted screws and nuts. I've never had a screw or nut I couldn't take out or off.