News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

Stromberg Carlson 1243

Started by FABphones, October 07, 2019, 02:35:14 PM

Previous topic - Next topic

FABphones

Quote from: Jack Ryan on October 09, 2019, 07:42:32 PM
..I would avoid water based ultrasonic cleaning fluids as well. It is very easy to rust some parts - especially springs - that way.

Jack

I mentioned this in my post #10 above (last paragraph of main block of text). This is why it is very important to dry the dial thoroughly. And another reason it is preferable to totally strip a dial for cleaning - no hidden or unreachable 'nooks and crannies' to trap fluid.
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

Jack Ryan

Quote from: FABphones on October 09, 2019, 08:09:08 PM
I mentioned this in my post #10 above (last paragraph of main block of text). This is why it is very important to dry the dial thoroughly. And another reason it is preferable to totally strip a dial for cleaning - no hidden or unreachable 'nooks and crannies' to trap fluid.

Sorry, I missed that.

A actually ultrasonically clean without disassembly. So far, if the dial is mechanically sound, I've had a 100% success rate.

Jack

countryman

Quote from: Jack Ryan on October 09, 2019, 07:42:32 PM
What do you mean by "automotive brake cleaner"?

Some such solvents contain organochlorides which I would rather avoid. Others are hydrocarbon based but then you are back into more common solvents.


Thanks FABphones for showing the ultrasonic cleaning process in detail. This dial seems to have a helical spring lying outside that will dry out trouble free. With a coiled spring in an encasement (like a clock mainspring) I'd be more hesitant.

The "brake cleaner" available here comes in pressure packs and seems to be non chlorinated. It's original use is de-greasing brake disks and drums. It is widely used in the automotive business as parts cleaner. Of course it needs to be handled carefully what skin contact, combustiblity and possible degradation of rubber or plastic is concerned.
Neither in automotive applications nor with dials I observed noticeable problems with brake cleaner so far. It seems to be much less aggressive than plain acetone and evaporates cleaner and faster than naphtha or turpentine. The parts will be de-greased efficiently and so dirt particles embedded into old grease can be removed easier or are even washed out right with the application.

FABphones

 :)

Quote from: Jack Ryan on October 09, 2019, 08:41:45 PM
A actually ultrasonically clean without disassembly. So far, if the dial is mechanically sound, I've had a 100% success rate.

Jack

What do you use in your Ultrasonic?
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

Jack Ryan

Quote from: FABphones on October 10, 2019, 07:06:10 AM
What do you use in your Ultrasonic?

I tried water, mineral turpentine and isopropyl alcohol. I wrote the first two up in "The Exchange" describing the preparation, cleaning process and the results. In order to determine the results, I disassembled the dials that were cleaned looking for parts that were not cleaned properly. I never got around to writing up the results of cleaning with isopropyl alcohol.

Here is the concluding section of the second write-up (mineral turpentine):

Conclusion
This experiment supports the previous conclusion that ultrasonic cleaning will restore a slow or sticking dial to proper operation if it is already correctly adjusted. Dials that are out of adjustment but in otherwise good mechanical condition (not excessively worn) will only require the necessary adjustments.

Some old oil was found on the dial shaft after disassembly. Although this will not affect the operation of the dial, some additional experimentation is required to determine how the cleaning process might be improved.

It is, however, important to remember that dials cleaned and adjusted in this manner may not operate correctly for as long as a dial that was refurbished "by the book" – only time will tell.

What's Next?
A water solvent may result in rust forming on the steel parts of the dial. Mineral Turpentine won't rust the dial but its smell lingers for days, it may have a detrimental effect on plastics (for example the case of the ultrasonic cleaner) and should be handled and disposed of properly. I'll try one more solvent - isopropyl alcohol (isopropanol).


The dials that were cleaned and those that were cleaned and adjusted are still operating properly and there is no sign of rust (yet). In the process of these experiments it became clear that solvents with the same name had different ingredients in different jurisdictions.

So far, isopropyl alcohol is working for me but I am yet to perform a post-mortem and write it up.

Jack