Ammy,

Something that doesn't get talked about enough is that there are a number of different manufacturers making connectors and looking in my hoop making supply box I have three that are different, even though they all do the same thing. Some are more or less made to connect simply and easily, while others have a lip in the middle of the connector that will not fit under the piping, and others have little plastic barbs that create obstacles. When I find connectors I take what I can get, but sometimes that means getting out the sander and sanding the obstacles away. With the case of the middle lip ring it's not going to go over that so don't worry about it and add some tape over it, providing you're getting the hoop connected on both sides right up to the ring.

Boiling water makes connecting hoops much easier, and while there are those who will tell you that 10 seconds in warm water will do the job, the hotter you get the hoop, thus the longer you keep it in, the easier it will be to add connectors. I typically stick an end into a boiling pot of water on the stove for about thirty seconds on 160psi pipe. If I'm making quite a few hoops there's no sense wearing myself out when I don't have to.

As for the hoops not laying flat, the tubing comes in coils and it's rather sensitive to heat. Every now and then I seem to get a batch that's a little warped. Perhaps it was sitting at a bad angle in the back of a hot truck, who knows, but the good news is that the polyethylene is just as sensitive to heat finished as it was before you made it. Wait for a sunny day and throw the hoop out in the grass in the sun where it can warm up. Once it's warm you can bend it back into shape and as it cools it'll be fixed. In the winter I've been known to use the blowdryer.

Another thing that can happen is that we forget that warm pvc pipe is really pretty moldable while it's warm and once it cools it maintains its shape. My guess is with your problem of adding the connector that you're leveling the pipe out while inserting the connector and it's cooling a little too much while you're trying to add it, so that when you're done you have a flat spot. It happens, but it isn't really due to the connector in my experience. It's usually due to me holding the hoop in a flat line too long while connecting the two ends together.

Perhaps our readers have other ideas for you as well. In any case, good luck and happy hooping!