how to get a stuck battery cover off?

[kshapero]

I inherited a pentax Spotmatic II. The battery cover will not come off. I took off the bottom plate. This did not help as the the battery area is sealed. any ideas?

 

[Jon Goodman]

Soak it in common white vinegar. The battery cover has become corroded and this will cause a greenish formation which bonds it to the threads. If you'll leave it in vinegar a few hours, it is likely to unscrew again. If it is corroded to the point it will still not turn loose, try applying some WD-40 to it and let that sit overnight. Good luck.
Jon

 

[Stu W]

A method that works well for me is to drill 2 small holes in the battery cover. Then a camera spanner will take the cover right off. If you don't have a spanner you can drill a small series of holes along the coin slot. Then take a atandard screwdriver, tap it into the slot-it'll cut right through the soft brass-and the cover should twist right off. I've used both methods and they work. Naturally you'll have to replace the battery cover. Stu

 

[kshapero]

Thanks Stu and Jon. I'll try Jon's method first, except I heard that one should never use vinegar. hmmm

 

[Pablito]

and how to you prevent the vinegar from getting into the rest of the camera? sounds risky to me

 

[kshapero]

and how to you prevent the vinegar from getting into the rest of the camera? sounds risky to me

That's not a problem because the bottom plate comes off easily with the battery attached.

 

[Jon Goodman]

Yes, remove the bottom plate. Vinegar will have no ill effects. Actually, the amount of mercury present in the corrosion will be small and not worth worrying about.
Jon

 

[kshapero]

It is soaking in vinegar as we speak.

 

[Xmas]

We put vinegar on french fries, delicious hmmmm

WD40 may be as corrosive, but it is no good on potatoes.

Noel

 

[Didier]

I've had this problem recently with a battery cover of a Petri 35 color. Vinegar did not help. I dropped some strong penetrating oil on the cover (US citizens may use Kroil Oil), then let the camera body stand on the bottom side up for two weeks, and then could screw the cover out as it would have never been stuck. It's worth to wait.
Didier

 

[dmr]

Here in the States there's a product called Liquid Wrench which you can get at any hardware store which works wonders in breaking free corroded stuff. Another alternative is oil of wintergreen, in the home remedy section of the drug store.

That green grody yuck that is the remains of old batteries can be nasty. It can actually follow along wires and corrode them along their path. 🙁 I found this out on my first attempt to resurrect a Mamiya SD.

 

[kshapero]

And vinegar can accelerate that process!

Chris

As in a good thing or a bad thing?

 

[dmr]

As in a good thing or a bad thing?

Well, vinegar is an acid, although a weak one, and most acids, even weak acids, will attack many metals.

I've always thought of vinegar as being for salad dressing and maybe cleaning windows, but never really considered it for cleaning cameras.

 

[kshapero]

well I DID soak the bottom plate over night in Vinegar with the battery cover attached. Just tried the cover. Came off easy as butter. No real crud inside but a dead battery.

 

[Jon Goodman]

Another battery cover miracle wrought! Coat the threads with a bit of Chap-Stick and they'll be like butter forevermore.
Jon