I'm an idiot! - Bathtub drain pipe question

[madforrit]

Hi everyone, first post here. Looks like a great forum and happy I found it.

I'm in the midst of installing a bathtub, and for reasons I can't explain, I measured only once (ugh) and cut the brass tail (drain?) pipe too short. Can I extend the pipe by soldering on a coupler/union, and if so, what kind of coupling am I looking for? I purchased a 1-1/2" copper coupling for the bath drain pipe (1-1/2" OD) but it's entirely too large...clearly I am missing some very basic knowledge here. A short length of brass pipe with threaded ends that could be used with slip nuts would also work, but I don't know if such a fitting exists. Or do I need to buy a whole new assembly because of my stupidity?

Sorry for what I am sure is a very naive question - I'm an advanced DIYer in everything BUT plumbing. I appreciate the help!

[kreemoweet]

There probably are tubular drain fittings you could use, but you're not likely to find them outside a specialty plumbing outlet if you insist on using
brass (a very old-fashioned and expensive way to go). Slip-joint extensions as short as 4" are available. Tubular drain pieces (such as you are using) do
not mix with copper DWV (drain, waste, & vent) items except via the use of special adapters. Similarly with Schedule 40 plastic and galv. steel DWV
pipes. Dimensions in each of those systems are "nominal".

[jadnashua]

There are tailpiece extensions for tubular drain pipes available - I think I've even seen them at a big box store, but more selection available at a plumbing supply house. These usually come with a beveled compression washer and a nut to make the seal.

[madforrit]

There are tailpiece extensions for tubular drain pipes available - I think I've even seen them at a big box store, but more selection available at a plumbing supply house. These usually come with a beveled compression washer and a nut to make the seal.

Thanks guys. I picked up a tailpiece extension at the big box store. Did the trick.