Hi again,
Are you considering installing a used liner? Maybe the one that came with the used pool you just bought? Let's consider some things before you try.
A lot of people will sell used pools and say "the liner is fine, it has never leaked." In most cases they don't mean to lie, they just don't know any better. Liners shrink and dry up as soon as the water is out of them. The older the liner the worse this is.
I get asked all the time to install used liners in above ground pools. I first try to talk the customer out of it, but if money is a really big issue, and they can't be talked out of it I have a simple rule. The liner must not be over two seasons old, after that I won't waist my time on it.
Before I go over all the reasons for not doing this, let me tell you how it's done.
You want to clean the liner up as best possible and then give it several hours of direct sunlight before attempting the installation. When the pool is ready for the liner lay it in the pool and align the skimmer and return openings. I don't go to the bother of actually hooking up the skimmer yet, I just want to know if the liner is going to fit.
Use cloths pins and hold the liner in place where the skimmer is lined up. You will need to have someone hold the wall at this point while you get the liner opened up and spread to the other side of the pool. Now go back to the skimmer and push the liner up against the cove just below it. Now go to the side of the pool just opposite the skimmer and see if you can get the liner to the cove and still have enough liner to go over the wall.
This sounds pretty basic but it is amazing the number of times I have done this where across from the skimmer the bottom seam is a foot or so away from the cove. When that happens, and you are holding the liner against the cove with your foot, there will not be enough liner left to go up and over the wall. That's when you know your chance is slim of this liner working for you.
If you pass the first test you can then go back and attach the skimmer and return. You then work your way around the pool pinning the liner over the wall with cloths pins. Once the liner is pinned start working the bottom. You want the liner centered as best possible, this is difficult because the will shift towards the skimmer, this is normal. If you centered the liner the portion under the skimmer would be too far from the cove.
So you have sort of have a lop sided liner to work with but it can still be done, just work the difference out evenly in both directions from the skimmer so the bottom seam is equal distance from the cove both ways from your starting point. This will usually cause some wrinkling on the sides of the pool, but if you can get the bottom smooth that's the best you can hope for.
Work on the bottom for a while, getting it as smooth as possible. With the liner centered and the bottom smooth, as much as possible for both, start a garden hose. For the next 30 minutes or so you should be on your hands and knees smoothing the bottom of the pool, pushing all the wrinkles to the outer edges.
Once the water is near the wall of the pool you should start setting the liner. Put your foot into the cove and pull the liner up tight and over the wall. Use your cloths pins to set it like this all the way around. With that done the installation can be finished.
Now, why would I not recommend this?
Because it would not look like this.
This is a brand new liner with a smooth wrinkle free bottom, smooth sides and a clean look. Your used liner will not look like this. If money is tight and you have to try, I understand, and I told you how to do it, but anytime it is possible, start your pool off with a new liner. Here are some of the benefits.
A smooth wrinkle free liner is easier to take care of and well be enjoyed a lot more, as well as last a lot longer. Wrinkles and footprints are hard to clean and cause wear spots, eventually leading to leaks.
You can spend a lot of time and effort just to find out that the used liner has shrunk too much to fit the pool. Now you have a pool wall up and no way to put water in it. Hopefully it will still be standing when the new liner arrives and hopefully you have built the framework around the pool to keep it up.