How to avoid stripping Screws when disassembling a Camera

[tlmester]

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" set screws, 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.
[Note to novices: you turn the screw to the LEFT (counter-clockwise) to unscrew it. Remember the phrase: Righty Tighty - Lefty Loosey. It is extremely unlikely that you'll come across a reverse threaded screw that turns the opposite direction.]

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!

[ekoe]

Great post. Thanks for those tips.
I've never tried 'freezing' the screw.

There's a terrific product I brought with me to the UK from the US called 'PB Blaster'. It's some sort of polymer based penetrating fluid. A little squirt will wick into the threads. It works great. I use to use it on my classic cars.

Also, there's namptha for dissolving any locking compound or hardened grease. Namptha is available in some hardware stores. Painters sometimes use it for clean-up. Also, zippo lighter fluid is supposedly the same as namptha.

[ekoe]

Also, to hold the screws in place I like using black nail polish.

[peaceman]

One further, maybe trivial hint: Use high quality screwdrivers -- and only such that fit 100% into that particular screwhead. There is a difference between PH and PZ screws and it is also cheaper to sharpen a flat screw driver precisely down to that particular shoulder bolt screw than killing the screw entirely with the wrong tool.

[PMarkey]

Timely advice ,Many thanks .
I have a Chinon 872 that appears to have a loose aperture blade , Hopefuly it's just a displaced leaf and not a broken pin on the plus side it didn't cost much (99p/$1.52) so nothing ventured nothing gained .



Paul

[tlmester]

One further, maybe trivial hint: Use high quality screwdrivers -- and only such that fit 100% into that particular screwhead. ...

Yes, you definitely need the proper screwdrivers. I purchased a set of precision screwdrivers -- down to 1mm -- before beginning the job. The Lens Dials were 1mm screws.

» Tue Sep 07, 2010 5:54 pm
Timely advice ,Many thanks .
I have a Chinon 872 that appears to have a loose aperture blade , Hopefuly it's just a displaced leaf and not a broken pin on the plus side it didn't cost much (99p/$1.52) so nothing ventured nothing gained .

Hopefully there isn't anything wrong with the Aperture. If so, you might need to "manufacture" a replacement part. :?