Notes to future repairers?

[Dan Daniel]

I am working on a Rolleiflex that has a ton of loose screws. Meter mount, lens board, etc. I asked the owner and she said that she travels a lot, uses motorbikes, small boats and planes, etc. I've seen such a 'shaken loose' camera before from someone shooting at the front of a nightclub and having the speakers rattle everything. Well, I am using a light (Permatex purple) thread lock on the screws in reassembly.

I recently worked on a camera where someone had used thread lock almost everywhere and it was a huge pain. I didn't understand what w as going on at first and ruined a scew (replacement was available).

For people who go inside cameras, would you like to see a note about the thread lock? If so, how to do this? Pencil inside back? Tape label inside back? Note in case? Thoughts on how to communicate possible issues to the future?

Thanks.

 

[Saganich]

Document on the receipt/report to the owner and it's up to them to pass the information on in the future. In or on the instrument is common in hazard communication like radiation or electrical skock...but there has to be an established symbol that communicates the extent of the hazard...will simply saying "Locktite" or "Permatex" on a label inside the instrument mean anything in 50 years? Who knows, but you can do both, document thoroughly in receipt and a short 3 word warning inside the instrument.

 

[BrianShaw]

I'd rather not have thread lock used where it was not specified by the manufacturer. But if it is used, as in this unusual circumstance, I'd recommend just documenting on the receipt so the owner knows, stating any limits of the warrantee, and not worrying about the future.

 

[Kino]

A small sticker with repair date and maybe "Low-Strenght Loctite used" would be my preference.

LS shouldn't cause any issue, but the red variant... you might as well weld the screw in

 

[Alex Varas]

I would use a pencil inside the reverse side of panels and the type of stuff used and the correct way to open the screws if by solvent or heat.

 

[retina_restoration]

If the notification is to benefit a repair technician in the future, write a note in pencil somewhere inside the camera where the next tech is likely to find it early in the disassembly process. Putting it in a note on the invoice isn't great because the odds of that invoice being divorced from the camera by the time it's needing to do its job is nearly 100%.

That said, I don't use Loctite anywhere in my work. But there are a few places inside the cameras I service where "locking" an adjustment screw is warranted, and my choice is to use bright red nail polish. That way, it's obvious to whoever services it next that I have used lacquer to lock some components in place.

 

[ic-racer]

I think the purple thread lock is a good option, but I’m curious to what others think

 

[Ian C]

Although this doesn’t directly answer the original question, I believe the following comments are appropriate.

Not all thread lockers are the same

The problem discussed in Post #1 indicates the likelihood that a stronger-than-appropriate thread locker was used.

I became familiar with Loctite products in my occupation in which various grades were used.

When using Loctite thread locking compounds, it’s important to match the type to the job. The type is identified by a 3-digit code on the bottle. The screws of assemblies that might require disassembly and reassembly for repairs, cleaning, and so forth should only be secured with a REMOVABLE thread locker. The specific type is indicated for the size of the screws used. The REMOVABLE types have a distinct blue coloring.

For screws used in cameras, lenses, and so forth, I have found that Loctite #242 REMOVABLE Thread Locker is the most appropriate. It does a good job securing properly tightened screws and used per the given instructions. The screws are easily removed with the appropriate tool when used correctly. The tool applies sufficient torque to break the bond between the screws and threads of the component in which they are installed. This allows removing them without damage. A fresh application of thread locker is required upon reassembly.

One thing that is sometimes overlooked is to push the tool into the drive socket (slot, cruciform, hexagon, Torx, Pentalobe, etc.) with greater force than the applied torque. Otherwise, the tool might cam out of the socket and strip it.

https://www.loctiteproducts.com/pro...ctite-threadlocker-blue/SAP_0201OHL029W4.html

https://www.loctiteproducts.com/ide...ker-red-or-blue-which-ones-right-for-you.html

I’ve not used the new purple Loctite #222. It’s described as “low strength” for easy removal of small diameter screws. There is more information available in the following link:

https://www.henkel-adhesives.com/dz...fference-between-threadlockers.html/1000.html

I’ve had no difficulty in removing screws of 2 mm and smaller diameter secured with Medium Strength #242 (blue) REMOVABLE thread locker.

Note: Other brands of thread locking material are available. They might not all use the same color coding. Investigate and be certain before using.

 

[Dan Daniel]

Thanks for the comments.

I know that thread lock is a sticky subject among camera repair people. Personally, I have used it only rarely and would prefer to not use it at all. Years ago a mechanical engineer told me that a light coat of grease was actually the preferred thread material because it allows for more tightening of the threads and more pressure between the actual surface forming the bond (upper bolt thread surface pulling against upper cut thread surface). He worked on larger scale engines and vehicles, though.

A while back I overhauled a camera for someone, and a couple of months later she was back, saying things were loose. Man, were they! Loosened screws throughout the camera. I went through, checked screws, gave a solid twist. I asked her how she was using the camera. She photographed at the front of the stage at a local night club. Ray Dolby had designed the sound system and it was very clean, from top to bottom. I assume it was the bass speakers which had vibrated it loose. After the tightening, she had the problem again. I added Loctite blue to screws and it held up.

I knew someone who photographed speed boats from helicopters. He had thread lock put on his Hasselblads during maintenence to avoid loosening.

When this recent customer told me that she travels a lot, small planes, mopeds, motor bikes, etc., I decided to use Permatex purple low strength thread lock. I have tested screws after a few days and they release (I know, it can take more time for full set). A Rolleiflex I worked on a few weeks ago, someone had used a serious thread lock and most screws needed to be heated with a pin blowtorch to release. I had some choice words for whoever did that.

@retina_restoration, you gave me a hint on one thing I have done- applied a nail polish on top of all screws with thread lock as a marker.

I will write a note inside the back explaining the blue (nail polish color) marks and the thread locker used.

Thanks again!!