Struggles with a stuck flathead screw on a Voigtlander Bessa 66 (Baby Bessa) - Penetrating oil not working

Ellyrion · Oct 24, 2022

Hi all,

I recently picked up a Voigtlander Bessa 66 for cheap as a fixer-upper - the bellows seem good, shutter works fine, lens is a little hazy but unfortunately the autostop winding mechanism seems stuck and I think I need to open up the top cover to unjam it (it needs to be set to "0" in order to free the winder to load fil, It is currently stuck between 2 and 3 frames).

To open the top cover I'm pretty sure I just need to remove one small screw above the viewfinder and then a flathead screw on top of the winding knob - however this screw is totally seized up!

I have tried regular WD-40 (maybe a mistake but it seemed like an idea at the time), WD-40 Specialist Fast Release Penetrant (left to soak for 6 hours) and heating the screwhead with a lighter to no avail. I have tried multiple screwdrivers and am currently using one from the Vessel TD-55 kit which fits perfectly but the screw wont budge.

Any ideas on how to go about freeing it?

Thanks!

John Will · Oct 24, 2022

I'm not familiar with the camera but have you tried unscrewing in both directions, it could be reverse thread.

Ellyrion · Oct 24, 2022

John Will said:
I'm not familiar with the camera but have you tried unscrewing in both directions, it could be reverse thread.

Unfortunately it wont budge that way either - I think its just badly seized up. Will try more penetrating oil overnight

John Will · Oct 24, 2022

The only time I had a screw stuck like that I heated it with the tip of a soldering iron put the screwdriver in place and gave the end of the screwdriver a sharp tap with a hammer (not too hard!)

AgX · Oct 24, 2022

Instead of heating I would try freezing, by means of freezing-liquid.

The ultimate solution is drilling it out, but you better got the right tools for it...

r_a_feldman · Oct 24, 2022

Try using acetone to loosen the screw. Put a small drop in the screw so it is drawn into the threads. Wait a few minutes, then repeat half a dozen times or so.

Dan Daniel · Oct 24, 2022

It is regular threading- counter-clockwise to loosen.

Have you tried leveraging the screwdriver with a crescent wrench or pliers? After all the other tricks, of course. Use one palm to press down on the screwdriver and turn with the wrench in the other hand. If you need to stop the camera from spinning, use your chest or stomach, depending on your table height.

And for heating, a soldering gun or true blowtorch will get results better than a lighter. A mini blowtorch might also spread enough to heat the surrounding knob, also.

Another possibility is to apply ammonia. It can break apart corrosion in some metals.

AgX · Oct 24, 2022

r_a_feldman said:
Try using acetone to loosen the screw.

So you think someone has cemented the screw. Good point.

Rick A · Oct 24, 2022

You should never use penetration oil on a camera, it migrates into places it should never touch. If you want to freeze the screw get a small canister of Ronson Butane lighter refill. Just invert it and spray directly on the screw. You might try alternating between freezing and heating with a soldering iron.

250swb · Oct 25, 2022

It looks like it could be one of those screws that could have had some thread lock applied in manufacture. If you don't know how deep it goes freezing it is a waste of time, that only works with shallow screws unless you put the whole camera in the freezer overnight (in a bag) then also apply some freezing spray (electrical shop). But heat may work better, it will travel down the screw and soften the thread lock or corrosion/gunge, just have all your tools ready to use while it's still hot. I don't think it will be a left hand thread because of the direction the dial normally turns.

AgX · Oct 25, 2022

A nightmare of mine with miniature screws is drilling out and then the extractor shearing off at level...

Never happenend so far.

Don_ih · Oct 25, 2022

AgX said:
A nightmare of mine with miniature screws is drilling out and then the extractor shearing off at level...

Never happenend so far.

You must have some extra small extractors.

gone · Oct 25, 2022

I would make 100% sure of the direction it's supposed to go, those are often reverse threads. If it can't come out any other way, take a chisel and snap off that bunged up screwdriver head, and when the knob is removed, the screw stem should be sticking out enough to get a pair of lock jaw pliers on it. If it accidentally breaks (turning the wrong way?), no worries. It can be drilled and tapped to put a new screw in there.

But, that's step B. Step A is to first see if someone you know has an impact driver. That might do the trick, once you take that little chisel and make a better slot in the screw. The screw material is undoubtedly not hardened, so it should be easy to work with.

Ellyrion · Oct 25, 2022

Rick A said:
You should never use penetration oil on a camera, it migrates into places it should never touch. If you want to freeze the screw get a small canister of Ronson Butane lighter refill. Just invert it and spray directly on the screw. You might try alternating between freezing and heating with a soldering iron.

I wouldn't normally as yeah it can spread easily - but on this camera the shutter and lens are totally removed from the frame counter mechanism. WIll see if I can find some lighter fluid!

Ellyrion · Oct 25, 2022

AgX said:
Instead of heating I would try freezing, by means of freezing-liquid.

The ultimate solution is drilling it out, but you better got the right tools for it...

I'm feeling like that might be the way I have to go eventually - what tools would you recommend?

Dan Daniel · Oct 25, 2022

Don't start drilling yet. More heat. And better grip on tools.

Look inside at the wind tab axle. Heat it up. You might be able to use a wrench on it while using a screwdriver on the slot of the outer screw.

And I'll say it again, having been inside a few of these Bessas- standard right-hand thread.

Ellyrion · Oct 25, 2022

momus said:
I would make 100% sure of the direction it's supposed to go, those are often reverse threads. If it can't come out any other way, take a chisel and snap off that bunged up screwdriver head, and when the knob is removed, the screw stem should be sticking out enough to get a pair of lock jaw pliers on it. If it accidentally breaks (turning the wrong way?), no worries. It can be drilled and tapped to put a new screw in there.

But, that's step B. Step A is to first see if someone you know has an impact driver. That might do the trick, once you take that little chisel and make a better slot in the screw. The screw material is undoubtedly not hardened, so it should be easy to work with.

Its thankfully a normal thread - someone else with a Baby Bessa has confirmed. I'll see If i can find someone with an impact driver!

Ellyrion · Oct 25, 2022

Dan Daniel said:
Don't start drilling yet. More heat. And better grip on tools.

Look inside at the wind tab axle. Heat it up. You might be able to use a wrench on it while using a screwdriver on the slot of the outer screw.

And I'll say it again, having been inside a few of these Bessas- standard right-hand thread.

Gotcha - I'll try more heat! Are we talking hot enough that it'll hiss when touched with a damp sponge or just too hot to touch? Will try gripping the wind axle instead, thanks

Dan Daniel · Oct 25, 2022

You have a lot of metal to heat up. The winding knob and axle will be heat sinks. The problem area is where the screw threads meet the wind axle. Go slow but keep heating for a minute or two. On and off with the heat. You are trying to saturate the wind axle without ruining the chrome on the screw head.

And then let cool down. No sense cranking on metal that is expanded and binding hard.

AgX · Oct 25, 2022

Don Heisz said:
You must have some extra small extractors.

One may make such one self, ready-made such seem not to exist.

And there always is the risk of harming the original thread.

AgX · Oct 25, 2022

Ellyrion said:
I'm feeling like that might be the way I have to go eventually - what tools would you recommend?

There are anti-clockwise drills that might screw out the stuck scre in the most ideal case. In any case the best approach at drilling would be perfect centering and diameter. But often ar finemechanis one does not know the original thread size.

Another approuch would neatly machining over slit and tip for pefect fit. But if one already fears to shear off the screw one rather should try longer at the hot/cold approach.

bernard_L · Oct 25, 2022

Having a similar problem I followed the advice of a mechanical engineer at my workplace, and used a liquid called Transyl, and it worked where WD-40 had failed. He had recommended that specifically for threads in Aluminium parts. Here is a UK reference (more expensive than on amazon.fr !!):

Sirius Glass · Oct 25, 2022

bernard_L said:
Having a similar problem I followed the advice of a mechanical engineer at my workplace, and used a liquid called Transyl, and it worked where WD-40 had failed. He had recommended that specifically for threads in Aluminium parts. Here is a UK reference (more expensive than on amazon.fr !!):

The URL did not work.

juan · Oct 25, 2022

WD-40 is NOT penetrating oil. Liquid Wrench and PB-Blaster are. Use one of them exceedingly sparingly. Use heat and cold. Be patient. I had a stuck screw on a Graphic View camera that two two weeks of daily treatment to loosen.

bernard_L · Oct 25, 2022

Sirius Glass said:
The URL did not work.

Strange, here (France) when I click on the link (to amazon UK) in my post, it just works.
Anyway, look on Amazon or elsewhere for:

Owatrol Transyl ATO Multi Purpose Lubricant Rust Remover

Disclaimer: I am in no way affiliated with the supplier of this product.

Struggles with a stuck flathead screw on a Voigtlander Bessa 66 (Baby Bessa) - Penetrating oil not working

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Owatrol Transyl ATO Multi Purpose Lubricant Rust Remover​

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Owatrol Transyl ATO Multi Purpose Lubricant Rust Remover