How to avoid stripping Screws when disassembling a Camera

[TerryM]

I want to share with you three of my techniques to avoid stripping screw heads when opening up a camera. Firstly, what you need to do is FREEZE the screw head with ICE. To prevent the camera from getting wet, just place the ice cube into a plastic sandwich bag, and push that against the screw head for about 30 seconds. Freezing will make the metal harder, and less likely to strip. In addition to making the screw harder, freezing also causes the metal to shrink a bit which makes it easier to unscrew. You will need to keep re-freezing it every 30 seconds until the screw comes loose.

My second technique when unscrewing a stiff screw is to not apply constant turning / torque. Constant turning is what will lead to the screw head stripping. When unscrewing a stiff screw, you need to use QUICK JOLTS. You accomplish these jolts by only very briefly applying the turning / torque with the screwdriver for only a fraction of a second at a time, and then you quickly let your hand loose on the screwdriver handle to stop the turning. These brief turning jolts, combined with freezing, will eventually jar the screw loose without stripping the head. For my third technique, it is also necessary to push the screwdriver VERY HARD into the screw head in order to prevent it from slipping. The screwdriver slipping is what wears down and strips the screw head, but hard pressure avoids this.

I want to make a comment on those tiny screws which hold the lens dials onto the lens. Those tiny lens dial screws are likely headless, and only consist of the cylindrical screw body with a groove on the end for the screwdriver. These screws are also likely only threaded into the dial itself, and only apply "pressure" onto the inner lens case to hold the dial in place. Those lens dial screws are also probably glued into place to keep them from coming loose -- so you need to pick away the glue before unscrewing them. After screwing them back into place, you can use a toothpick to apply a small amount of paper glue on the end which will keep them tightly in place.

There might be some screws hidden behind labels -- so you may need to carefully pry away some labels. Use a piece of masking tape to securely hold the screws in the order you remove them -- they're tiny and you don't want to lose any of them. These techniques worked with 100% success for me when removing all necessary screws to open up my Super8 camera, and they will also work for you. Good luck!

[mike c]

Good advice.

[nick mulder]

Great advice, until you meet a reverse thread and make it even worse ...

Best tactic is to know how to spot likely spots that they'd be used before you go tightening them - where the action of the piece is such that the net forces try to unscrew the bolt (?)

[AgX]

My advice would be to have a great assortment of screwdrivers, and not to hesitate to grind a blade to the best fit.

Terry,
Have yo thought about using `cold spray´.

[TerryM]

Great advice, until you meet a reverse thread and make it even worse ...

I knew that somebody was going to bring up the unlikely scenario of a reverse thread. Have you ever actually encountered a reverse-threaded screw on a camera?

Note to novices: you turn the screwdriver to the LEFT (counter-clockwise) to unscrew it. I don't think you'll come across a reverse thread.

My advice would be to have a great assortment of screwdrivers, and not to hesitate to grind a blade to the best fit.
Terry,
Have yo thought about using `cold spray´.

Yes, definitely make sure to have the necessary tiny screwdrivers right down to 1mm. Those tiny screwdrivers are made with hardened metal. Don't try to use too large a screwdriver! The lens dial screws are likely 1mm.

I've not heard of cold spray. Is that a lubricant? With freezing I didn't encounter any problems.

[nick mulder]

The Mamiya RZ67 ProII back uses reverse threads (assuming we're talking metal thread/bolts and plastic screws also ?)

The cold spray is often found in electronics stores - used for instance in keeping electronic parts cool whilst working with heat nearby (soldering etc...)

[AgX]

Yes, definitely make sure to have the necessary tiny screwdrivers right down to 1mm.

I've not heard of cold spray. Is that a lubricant? With freezing I didn't encounter any problems.

1mm is waaay too much tolerance, even for "around the house" screws!


Cold Sprays are organic liquids with a very low boiling temerature. They are made by compressing gases of that substance in small spray cans. Sprayed on a surface they evaporate and yield evaporation cold. They are used in the technical and medical world.
Most, if not all are flammable.

[Marco B]

1mm is waaay too much tolerance, even for "around the house" screws!


Cold Sprays are organic liquids with a very low boiling temerature. They are made by compressing gases of that substance in small spray cans. Sprayed on a surface they evaporate and yield evaporation cold. They are used in the technical and medical world.
Most, if not all are flammable.

I think I have seen that stuff being used when they needed to replace my water meter in my house two years ago. The guy had a can with a kind of wrap attached to it, that was wrapped around the metal pipe to freeze the water inside it before cutting it to replace the water meter...

Very handy...

[steelneck]

Most, if not all are flammable.

It could also be carbonate, like in some fire extinguishers or for making soda water. Ice from this evaporates at -78 celcius.

[AgX]

Yes, but CO2 needs stronger containers, as it will liquify under much higher pressure.
The soda making capsules contain CO2 gas not the liquid.


Back to sticking screws.
Ideally the cold is applied to the screw only, as with that (deep frozen) ice cube.
Simply spraying the screw head (especially in sunk heads) would be less effective than applying the liquid that way that it won't reach the body where the screw sits in.

At least I guess so...
I mean: will a hole that sits in a much larger body shrink or extend, when cold is just applied to that hole??