Waterproof training pants with free pattern

Here are instructions to make waterproof training pants. These are "low bikini cut" style and trim fitting. The pattern fits my 20lb, 9 month old with a little room to grow.

The trainers have a PUL outer and a flannel inner with a soaker of 3 layers of flannel, the sides are attached with snaps, bound with 1" FOE, so that they can be easily taken off when wet but still pull up and down. You could make different variations on this:
-flannel inner, outer and soaker for non-waterproof trainers
-flannel inner, outer and soaker with a hidden waterproof layer in the soaker
-another type of material in the soaker, i.e. hemp
-sew together the sides and leave out the snaps
Download Pattern Some download times are long.

Here is the flannel inner layer with the 3 layers of flannel for the soaker. I have pinned and sewed all three layers of flannel, the soaker, to the inner flannel layer and used a wide and close together zig zag all the way around. You run the zig zag over the edge of the soaker flannel so that the edges are protected from fraying. I like to do this instead of serging the edge and then sewing it on because it takes less time and works just as well.
Cut out your PUL layer using the same trainer pattern as you did for the flannel inner. I draw the pattern onto the PUL and then use paper clips to hold the fabric still (its pretty slippery) while cutting.

Hint: I like to make my pattern pieces out of cardboard from cereal boxes, they hold up well and are easy to trace.

Hint: You don't want to use pins with PUL because this will poke holes into the waterproof layer and make it leak. You can use bobby pins, paper clips, or clothes pins instead.
Place the right sides together (the flannel should have the soaker facing out so that when you turn the trainer the soaker will be hidden on the inside). Use the same paper clips to hold the PUL layer to the flannel to prepare for sewing.
Sew the legs, the back and the front with a straight stitch and a 1/4" seam allowance. Leave the sides open. Take the paper clips out before the machine runs over them.

Attaching the elastic is a tricky. You want to use a medium sized zig zag. Take a long length of 1/4" wide elastic, don't cut it in advance. Anchor the elastic to the PUL side at the edge of the leg by backstitching, now pull the elastic with your right hand and guide the diaper with your left hand. Sew along the seam allowance so that the machine tacks the elastic down to the trainer. You will see it start to bunch up behind the foot. When you get to the end of the leg cut the elastic. Repeat this for the other leg, the front and back.

Hint: Pull the elastic by 50% (not fully tight) these trainers are fairly trim and if you pull the elastic too tight they will be too tight around your little ones waist and thighs. Try to pull the elastic the same amount for each seam so that the trainer is symmetrical.

Hint: Sewing the elastic to the PUL side of the diaper will cause the flannel to roll in on the finished trainer so that the PUL will be lying against your little ones legs to prevent wicking when wet.
Here is a picture of the trainer with all the elastic on. You can see that it curls a little but not too much because I only pulled the elastic by 50% of its stretch. You can see that it is pretty much symmetrical, no one side is curling too much more than any other.

Turn the trainer inside out through one of the back sides (there's more room there). Pin the sides so that the PUL lies flat and the elastic is straight on the ends. (I know I said not to pin PUL but you will put the snaps here anyway). Roll the end so that the flannel is rolled in, so that when you look at the right side all you see is PUL. This may result in the flannel being a little buckled but this is not important.

Hint: If you wanted to topstitch the trainer, now would be the time. Sew a straight stitch just outside the elastic, being careful not to catch it. You can do this with the waist and the legs if you wish. This may cause wicking which is why I don't do it.
If you wanted to sew the trainer together (and omit the snaps) you would pin with the PUL layer together and sew up the side seams. Turn inside out and be done. If you want to add snaps DON'T do this step.
To put on the 1" wide FOE run an inch through the machine sewing with a very wide and close together zig zag before you put the trainer in.
Sink the needle, raise the foot, open the FOE and then place the corner of the side of the trainer under the foot so that when you lower the foot it will rest on the trainer. The pins might poke through the FOE where it is folded but this doesn't matter. Then place the rest of the side along the FOE and fold the other side of the FOE on top. Lower the foot.
Sew along the edge being careful to catch both the flannel and the PUL layers in the FOE (don't stretch the FOE, you're using it as a non-wicking binding not as an elastic). When you reach the end of that side sew about 5 more stitches on the FOE without anything between (this is important because you will be folding over the excess and using to anchor the snaps) and then repeat the above step for the 3 other sides of the trainer. You don't have to cut the FOE, just keep inserting the sides and sewing along. If you are making more than one trainer you can just keep adding them on until all sides of all the trainers are bound.
Cut in the middle of each section of FOE to release each side of the trainer.
Poke a large needle through the trainer at the edge of the FOE where it meets the inner elastic (feel with your fingers to find it). This will make it easier to put the snaps on.
Take the front of the trainer and push the cap through the hole you made with the pin, fold over the FOE and push it over the sharp part of the cap. When you look at the PUL side of the trainer you should see the smooth side of the cap.
Use your snap press to put the rest of the snap on, thereby securing the FOE under the snap and finishing it off.

Repeat for the bottom of that same front side and for the top and bottom of the other front side.
For the back sides fold over the FOE first (towards the flannel) and push the cap through so that the smooth side of the cap is on the flannel side.
Put on the rest of the snap with the snap press and repeat for the other three snap locations in the back.
If there is excess FOE hanging off after the snap has been put on, cut it as close to the snap as possible with scissors.
Put all the snaps together and you will have a finished pair of trainers.