Kroil, like Kreen is a great product.
Yesterday, I went to a few "Garage Sales" and picked up some nice vintage Penn Conventional Fishing reels for deep sea fishing and trolling. Most, if not all, may have been bought years ago and saw limited use since they were still in their original boxes.
On some of these reels, the reel handles would not turn, the spool would not spin and the reel seemed all gummed up with sludge that had dried out and hardened over the years.
Most of these reels were kept in homes and not stored in the garage where they would corrode. Due to non-use in quite some time, the reel gears, bearings and levers did not operate smoothly.
I took these Fishing Reels home, opened them up and completely sprayed both sides of the inner reel plates down to the gears and bearings with Kroil. I let them sit for a couple of hours and sprayed them again. Lots of sludge, grime and grit came flowing out of these reels and I could finally see brass and/or stainless steel gears and parts. I sprayed the bearing housings on both sides and the sludge flowed out from these. Now the handles turn, the spools spin like a top and the gears are shining.
Kroil, like Kreen, must dissolve all the built up sludge, old hardened lube and grime that accumulated over the years.
Now, all I need to do is pull the bearings, soak them in some Kroil and see if they need replacing, put in new metal drag washers and fiber drag washers, re-spool with mono and they should be good to go fishing.
I don't know if another product would work the same on these reels....but I reached for Kroil and I got some great results. IMO...Kroil worked like a champ.
Now, I have 8 really nice vintage Penn Conventional Reels that only need some minor parts to work like new again.