Loctite on shutter screws

I have a Copal shutter that was having problems getting stuck on the slow speeds. I tried to remove the two screws for the escapement, and I failed. I tried putting drops of MEK on the screws as well as heating them up with a soldering iron. After a certain point I felt like I would damage or snap the heads off the screws if I tried any harder.

A few weeks ago I brought this shutter to a camera repair seminar, and I gave it to the guy leading the whole thing. He went at it really hard, and both screws let out a crack before they started moving.

I found there was a white substance in the threads. I'm wondering what this could be? Possibly some form of loctite? The only stuff I have that resembles this is teflon thread sealant. So, I'm wondering if some form of treatment on the threads in shutters is common practice and advisable?

Everyday Super glue?

I always used my wifes transparent nail varnish. Does the job and easier to remove a screw than with Loctite

Here are some recent threads regarding thread locking compounds applied to threading used on cameras and lenses with comments:

https://www.photrio.com/forum/threads/notes-to-future-repairers.219165/

https://www.photrio.com/forum/threa...-f5-disassembly-question.219187/#post-2979953

I've seen thread lock on escapements here and there. Many older Compur Rapids and earlier Synchro Compurs have a red thread lock on the escapement screws. This is NOT the same as today's Loctite red. This release with 'medium' twisting, no heat needed. I haven't run into this much on Copals but that could just be luck. A couple of Mmaiya TLR lenses had a white compound but it didn't take a lot to get it to release.

Early Nikon SLR lenses are famous for thread lock on the rear, holding the mounting flange. Dirty white color as I remember.

I assume the Compur red is factory as I run into again and again. Not certain on your Copal if it is factory or added later. I know a recent Rolleiflex I had that had thread lock on side panels and such was not factory.

Along with MEK, acetone, and heat, a screwdriver with a secure fit is important. No slop in the slot. Many screwdrivers have a square or hex handle; you can use an adjustable wrench to get leverage but be certain to have a stable setup and apply strong downward force when twisting.

Should you apply thread lock? I'd say no. Unless you are very familiar with industrial fastening and the variety of thread lock compounds and are certain you are hitting proper 'retention force' or whatever it is called, the odds are that you will make a mess, most likely for someone else down the road who won't be able to give you a slap across the head for doing it to them.

Yes it's a screw locking agent. Maybe Threebond or a predecessor. Sometimes you can access the screw tip from below were the solvent will be more effective. As @Dan Daniel says you need the right screwdriver (easier said than done).

PS. Compur used "Glytpal", a sort of varnish?