Stuck rangefinder screws on Leica IIIc

[tony.m]

Hello - I am trying to remove rangefinder off my Leica IIIc to replace shutter curtain and it seems that the screws are stuck (I may partially damage one of them). I tried to use acetone and hot blower without success, it seems that screw may be glue or epoxied. Is there any trick for removing screw?

Thanks

 

[Erik van Straten]

The trick for screws is to put some oil on them, wait a few weeks and try again. Oil gets everywere.

Erik.

 

[Thud]

Use Kroil oil. It's a penetrating oil. Use it sparingly. Let stand for a while then try to remove screw if not able to get it loose, try later.
Becareful with it it will migrate all over. Again use sparingly

 

[raydm6]

I see you applied heat. Maybe not enough?

See the following comment from this article:
https://richardhaw.com/2015/12/23/ca...ir-essentials/

Dave Summer
Apr 09, 2019 @ 20:07:37

Hi Richard I bought the micro screw extractor set SK11 No.4 (set of 3 sizes) to try to remove a damaged bayonet screw and the extractor stripped on the first try. I was very suprised that the screw didn’t move at all.
The best thing I’ve found for difficult bayonet screws is to use a micro butane torch to heat the stuck screw. It has worked every time. Now if I can find a good quality extractor set to remove the stripped screw I’d be happy.
Keep up the great work you are doing. I enjoy reading your blog. Thank you.

Butane Micro Torch
https://www.harborfreight.com/butane...rch-63170.html

 

[tony.m]

I did try oil as well, mix with benzine. But I guess, i didn't wait for weeks (just a few hours). I will try to leave it longer.

I used hot blower used to solder/remove SMD chip, but I set it to around 170C and used it for may be like 10sec. I think Butane is much hotter than that, won't it damage the camera, the screws are right under the rangefinder.

 

[View Range]

One thing you can easily try is to put the screwdriver on the screw and tap the end of the screwdriver with a hammer. You are trying to get some axial movement between the screw thread and the hole thread. This tends to work better with larger threaded assemblies, but is worth trying with small screws.
A fine tip on a soldering gun can also be used to melt glue on screws.
On problem with the normal small screw driver is that it is hard to generate enough torque and keep the screwdriver in the screw's slot. There are two ways to generate torque while pressing the screwdriver into the screw head. 1) Drill a hole in the screwdriver handle and put a rod through the hole. You now can generate more torque. 2) Get screw driver (slotted and Phillips) bits from the hardware store. Carefully grind and file the bits, which will be way too big, until they fit the screw slot perfectly. Put the bit into a tap handle. You can now generate lots of torque while pressing the bit into the slot.

 

[TenEleven]

All the tips above are already covering the bases and very good in my opinion. Also do not underestimate the power of continuing small taps on the screw. Put a screwdriver on it. Then hit the head of that screwdriver with another driver. You're not trying to hammer it, just generate some movement to help the oil which you hopefully put on earlier penetrate and dislodge the debris. Just keep going. Try different angles. Tap gently but persistently.

 

[tony.m]

Got it. Thanks all. It's still stuck, but I will patient on this.