Here is the process step by step. Buy a large pool and a smaller one,the big one I used is 1.12m (44") in diameter. The top ring is obsolete and can even interfere so I cut it off. (Make sure the rings are not interconnected and each has a separate valve.) Draw the outline of the inner pool, it makes it easier to apply the glue. I used all-purpose cement but you can use Vinyl glue which is designated for inflatables. However since it's more expensive and durability is not an issue I went for the less expensive glue. Apply glue on both sides and let dry for 10 min. --Author: Oferfal