At the church, there is a 45 minute rated fire door, with closer and three hinges. Wood door. The hinges groan a bit, make some kind of noise while the door is closing.
I tried opening and closing the door, with my fingers lightly touchng the hinge, and can't tell which of the three is making the noise. So, on principle, I dosed all three hinges and the door closer pivots with WD-40, and that didn't seem to help much.
Today, several days later, I return to the building. Spray the hinges with brake cleaner, to flush out whatever old lube was there. And then, spray the hinges with LPS-1, leaving a non oily film. After the solvent flush, the hinges got noisier. And then the spray, and they went back to about the same noise level as when I started.
I havn't whacked the hinges with a hammer and screw driver to check for removable pins. If they were, I'd pack in some axle grease, and pound the pins back in.
What other ideas, for squeaky hinges? What works?