Three things can commonly ‘seize’ a chain:
- Mechanical deformation (burrs, dings, bent links, etc.): requires mechanical intervention.
- Dried up, hardened, grease: usually loosens up with a thin lubricant (3-In-1 Oil, WD-40, etc.), and some manual manipulation.
- Rust.
In the early part of the thread that
@H-Ranch mentions, above, I received a lot of rusted chains.
Some, had only light surface rust, which I found reasonably easy ways to clean (citric acid, vinegar, EvapoRust, etc.).
Some, had deeper rust, between the links, and around the rivets.
RUST EATS METAL!
REMOVING RUST DOES NOT REPLACE LOST METAL!
(did I just say that out loud?
).
So, while I could clean up some badly rusted chains for display use only, I would not encourage people to run those chains on working saws.
One of the solutions I tried was the ATF/diesel fuel, ‘magic mixture’, which was reported with rave reviews. Aside from the stink of diesel fuel, it did not work on the chain that I tried, even after many months.
I think that it may work as a penetrating lubricant on some mildly rusted items.
But I have had more success with citric acid and Evaporust. I would try electrolysis again, although, it blew some chrome off one chain (might have been loose?). Others have reported good results.
Philbert