While redoing the drain run for my tub on the floor above I, of course, jiggled the tub drain fitting while installing the new (removable) ABS P-trap. The drain fitting was not very snug. Maybe 75 years of time has degraded the sealing washer and/or plumbers putty to make it looser than I would have expected. Now with just an inch of water in the tub it drips several drops a second. It never used to leak before I "touched" it. If all the framing was open on the floor above I'd just remove and rebed the overflow pipe/drain fitting assembly. The framing is open underneath but there is a 2 x 4 sill plate and sub floor close to the overflow down pipe as well as the brass compression ring Tee that connects the drain pipe to the overflow pipe above and the P-trap below. I am not sure I can get the assembly off without a lot of demolition on the upper floor. If I could unscrew the drain fitting from under the tub I would do that and work a new sealing (rubber?) washer and/or plumbers putty onto the mating surfaces and retighten it all up. The problem with this is that I am not sure how this drain plug fitting is even screwed onto the tub. Beneath the tub drain hole is a nice cast brass receiving ELL with a 1.5" brass pipe leading horizontally into the Tee. This horizontal pipe also has a rod in it that actuates a pop-up stopper in the drain plug fitting, much like the common pop up of a bathroom sink. (this is not the same tub drain stopper that I have seen before that has a 1.5" diameter cylinder that lifts up and down within the overflow pipe.) Inside the tub is a smooth chromed brass flanged drain ring "plug". I assume this flanged drain ring plug is male and is screwed/threaded onto the female cast ELL fitting beneath the tub, but there is no obvious "place to put a wrench" to unscrew the smooth flange drain ring plug. (I don't think I have to remove the pop up actuating rod to do this though). The cast brass ELL has a couple flats to get a large crescent wrench on but how do you hold onto the flange ring drain plug inside the tub to unscrew it? This house was built in 1941 and has all the original plumbing fixtures and they are all American Standard so I assume the tub drain is also made by them. Can anyone tell me how to separate/unscrew the top chrome part of the tub drain ring plug from the underneath cast brass ELL part? Alternatively I am thinking about using a crevice seeking/capillary flowing sealer that marine stores have for sealing small leaks of all kinds; (Captain Tolleys). Its package has 8 pictures of applications including a kitchen sink but I'm not sure this means its good for sealing plumbing, (they just mention kitchen sinks and counters in the text). I'm also concerned that if I use this sealant that it will (glue) make it harder to separate the top flange ring drain plug from the underneath part of the tub drain fitting. I suppose if I apply the sealant just to the under tub fitting it will not reach the threads and so this may not make removal harder. Many people rave about this Captain Tolley's crevice sealant. Thank you for any advice on: How to unscrew the tub drain fitting? Should I use the crevice seeking sealant? Eric