Rust penetration on siezed moving parts?

[cmdesign79]

I have an older Starrett Protractor/combo square I happened across in a box of old tools from a yard sale. Unfortunately said square has seen some neglect and has been allowed to become rusted. The protractor is completely frozen. And the screws that hold the level glass and level bracket on refuse to turn as well.

I have soaked it all in vinegar to remove surface rust and hopefully weaken any rust in tight areas, then in PB Blaster, I have tried hitting it with a hammer soft enough not to damage it but hopefully hard enough to shock it and break some rust. Due to the extremely tight tolerances on Starrett tools, I am uncertain if pb blaster is even able to get into where it needs to be, as its so tight you almost cant even see that there is a seam there. So far I have the tool looking excellent considering the shape I received it in but have had absolutely no luck on getting the protractor to budge at all.

Any suggestions? I'd usually try heating it but I really dont want to burn up the level glass and I certainly dont want to warp a precision instrument such as this.

Sent from my Z982 using Tapatalk

 

[Toolmaker65]

If you were able to get the clamp screws out, I would say tap gently on the movable level insert with a nylon or other plastic 'punch' to push it out. Since the clamp screws have a spacing washer under them, it may be that the screws are bound by the washers as well as the threads. Try a penetrating oil such as Kroil and let it sit for a day or two. Also, try to cushion the jaws of a pair of pliers with some 'heavy' brass shim stock (so you don't butcher the screw heads too much) and tighten them slightly if possible before trying to loosen them. If that doesn't work, I would try drilling them out with either a left handed bit or a regular bit that is close to the body diameter so that you can retap the holes.

 

[Shelbylex]

Try Evaporust. Soak it, try to move, soak more... couple of frozen tools I restored required 48 hours... If it’s stuck, turn it even if it’s fraction of mm and let it sit more...
Please post the picture - it’s always harder to give advise w/o seeing
... and after everything is done - make a ipicture to our new Starrett post...

 

[larry_g]

If you expect a precision tool when/if you get it working I think you will be disappointed. For me I find that Hoppe's #9 gun cleaner works well on cleaning up these tools, cleaning not derusting.

lg
no neat sig line

 

[droach77]

I have restored over 100 hand crank post drill presses, many of them which had sat outside for years and without a single part that moved. I use WD-40 and lots of PATIENCE. Have sprayed down drill presses every day for a month before things started to loosen up, followed by gentle hammering on the thing . Eventually, however, they all free up.

Dan