Complete IG rehab--skimmer and return question

Hi everyone. We are in the middle of a complete reahb, this is our second try. We have a 16x32 steel wall/vinyl lined IG. bought the wrong liner last year and had leaking returns. somehow the steel return hole got enlarged.
Ordered a new skimmer because the age of the existing one is unknown. also the skimmer gasket between the steel wall and the skimmer has aged and there are gaps.
I ordered a new skimmer, and they sent me one for a concrete pool. Can we still use this? what are the differences? its the same model that was already in there, I beleive. ITs an admiral s-15 model # 84120100.
also the guy at the pool store said to put the returns on opposite sides of the pool, but I cant remember what diameter key hole bit he told us to use. this is for standard hayward returns.
also any recommedations on where to place these returns as this pool is 30+ years old and was empty for 5+ years. some of the walls have bowed out slightly.
Please help!

On Hayward skimmers, the ones for liner pools have faceplates and gaskets, screws and also a lip on the sides and bottom into which you can srcew through the panel and secure the skimmer - the crete skimmers don't have any of this, because it's not needed. I don't know about the admiral ones, but i would certainly double check that the one you ordered has the faceplates and gaskets!.

Positioning of the returns depends on where the skimmer is located, if you'll tell me where the skimmer is (ie, center of the pool or 5' out from the deep end corner... etc), I'll tell you where to put the returns. The Hayward SP1408 through wall returns have 2 1/2" threaded shaft so the hole should be ~2 5/8" - large enough to get the return into the hole, but not so big that the flange doesn't catch. As long as the walls are still structurally sound, a little bowing after 30 years is ok. As long as you are adding new returns and a new skimmer, I would definitely pressure test the lines unless you plan on running all new plumbing.

Good luck with this version of the new liner! Get back to me on the skimmer and I'll tell you where to put the returns.

Waste, thanks for jumping in, I really appreciate your guidance. The skimmer currently is about 5 ft from the deep end. Both the returns are currently on the same side as the skimmer, one on the deep end, one on the shallow end. We are re-doing all of the plumbing, as this is our second and last attempt to make this thing right. The pool store guy told me to put on on one side and one on the other side. But we have access issues, and I dont want to be digging holes to China, so I would like to put them both on the opposite side of the skimmer. Do you think that is ok?
My only concern with relocating the returns is finding a plumb, level location, as I know it wont be watertight if everything isnt just right. I wish we had the money to hire it out, but things are tight and we are do it yourselfers. Thanks for all of your help, we'll keep you posted on the progress :)

Having one in the shallow end on the skimmer side and one in the deep end ~opposite the skimmer would be optimal for your set up. However having the one opposite the skimmer and the one in the shallow end be on the shallow end wall ~ 3' out from the side opposite the skimmer would also work well. What you are trying to do is get the water to move in a 'circular' motion around the whole pool so that any floating debris gets to the skimmer for removal before it can sink and require the vacuum to remove. If the skimmer had been in the center of the pool, you could have put both returns on the skimmer side wall, one at each end and the flow pattern would have had the water being forced to the center and into the skimmer - having the 2 returns on the opposite wall defeats this flow pattern because it will direct the debris to the center of the pool on the other side than the skimmer:(

The hayward 1408 inlet/ outlet fittings don't have to be 100% flush against the wall - the flange is behind the liner and the faceplate against it is what seals the liner - but it's best to have them ~ flush to the wall (the 1408s work on kidney pools so if the radius of the bowed wall you are working with is less than 6', all is fine).

I'm here almost every day if you need to bounce any ideas or questions off me. Good luck with the project!!:cool: