K-1000 Stuck Battery Cover
My brother gave me his old Pentax K-1000 camera today but the battery has leaked and the cover is stuck shut. I can't unscrew it without risk of stripping the slot.
What do you think I should use to unstick the cover?
Since the battery electrolyte is likely to be alkaline, I could use a weak acid like vinegar. I've also got various types of penetrating oil, carb cleaners, Stoddard solvent and/or WD-40.
What's the best thing to use which has the least risk of causing more trouble than it solves?
Hi, you might want to check everything else before starting work if the camera has lain unused for some years. Lens diaphragm may be sticky, no slow shutter speeds etc. If you use WD40 or similar, please don't spray it on. Spray a little into the cap and dip a screwdriver into it, place droplets where needed. I'm not familiar with US coinage but you need to find one that fits perfectly - or make a tool that does - to avoid damage. The battery box is plastic and too much force will break it.
Haven't worked on a K1000 in about 15 years but the bottom cover is held by just a few screws, 00 crosspoint driver needed. Connection wires to the battery box may also be corroded. Sometimes they can be resoldered if scraped clean but sometimes need replacement - corrosion can track right up the conductor inside the sleeve. If wires do need replacement quite a bit of dismantling is necessary.
Since everything on the K1000 works without batteries except for the meter you could just use a handheld meter if you can't fix the problem.
I have run the camera through all of its settings and shutter speeds. Everything seems to work. Aside from the battery cover, the only problem seems to be dust.
I have tried to unscrew the cover with the proper coin. Used both a US Quarter (25¢) and a US Nickel. (5¢) Nothing seems to work. Any more force will risk damage. It's stuck on pretty good.
I will use a cotton swab to apply the liquid. First, I will wipe the outside clean with just plain water on a cloth. Then I'll swab a few drops of penetrating oil like "Liquid Wrench" on it and let it sit for several ours and try again.
You are right about the possibility of corrosion inside the battery compartment. I have been cringing at the thought of what I might find. I have the tools to make basic repairs but after taking the cover off and looking inside I might decide to quit and look into the cost of repair or replacement.
If the battery cover is on the bottom of the camera body, remove the bottom, and soak [just the bottom ]in hot water for a while. Do not use any penetrating oil, especially WD-40, on your camera. When you are finished, neutralize the acid and clean thoroughly.
BTW: the big kid in my avatar is my hero, my son, who proudly serves us in the Navy. "SALUTE"
The battery cover on the K-1000 screws into the base plate, and the base plate is attached to the camera by just three small screws. It would be easier to remove the base plate and soak it in white vinegar to clean off the leakage. Note that the center screw is a smaller size than the two outer screws. If you don't feel comfortable doing your own repair, you could have a professional camera or jewelry repair person remove the screws. If you decide to do it by yourself, make sure you use a screw driver that's the correct size and of good quality. Press down firmly as you turn the screw to avoid stripping the head.
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The base plate came off easily. Cleaned the corrosion off the base plate with some stop bath on a cotton swab. (Acidic stop bath neutralizes alkaline battery electrolyte.) Carefully swabbed out the battery compartment. No apparent damage inside. The camera was stored upright so I think the battery chemicals drained downward, sparing the inner workings of he camera.
"Liquid Wrench" did not work on the stuck battery cap. (After the base plate was removed from the camera.) Now soaking in scalding hot water. Hoping that thermal expansion will do the trick.
I noticed that there are two drilled out indentations on the inside of the battery cap. They might offer a more substantial grip on the part if I can find an appropriate tool to fit between these lugs. A wide, flat bladed screwdriver might work but I don't think I have a screwdriver wide enough. Will search my workshop to find out.
Okay, so work in progress... Thanks for your help so far!
Maybe you can insert the ends of a paperclip into the cap's air holes, twist them together, and use it as leverage by grabbing the paperclip with a pair of pliers and twisting the cap.
since the baseplate is already off, put the whole thing in a vice with a plush towel
between the baseplate and jaws ... not tight, but not loose
then put your penny in a vice grips .. and it will hopefully give you the extra torque
you need to unscrew it. use the biggest the vice grips you have for maximum torque ...
- good luck!
Okay! Removed the cover!
After the base plate was off, I soaked it in scalding hot water for several minutes then used a home made tool to open the cap using two lugs I found inside the cap.
See attached images.
I made the tool from a piece of 5/8" by 1/8" aluminum bar stock. Used a grinder to create a tip 7/16" wide and shaved the thickness down to a wedge.
I was able to apply enough force to the part to open it without much trouble at all. It only took me about a minute once the tool was made.
P.S. - Don't forget! When you are working from the "wrong" side of the part the threads appear to run backwards from the normal way! Where you turn the cap counter-clockwise to loosen it from the normal perspective, you now need to turn it clockwise when working from the reversed (inside the camera) perspective.
Thanks for all your help!
Now, I'll dust the camera out with some canned air and I should be back in business!
Last edited by Worker 11811; 06-15-2010 at 05:33 PM. Click to view previous post history.
Great job! I was going to suggest snap-ring pliers, or two small drill bits clamped in vise-grips, in the vent holes. But those two little spot-faced areas came in handy. I've worked a lot in manufacturing, and am wondering why they are there. I figure they have something to do with fixturing for the slotting process on the face of the cap.
That's a good point about how the camera being stored upright avoided extensive damage.