As seen on this thread:
Right-click any image and choose "Show Image" to see it bigger!!
You will need...
a yard each of outer and lining fabric.
1/2 yard or less of some sort of waterproof, wipe-clean stuff for the changing pad.
(For the love of pete DO NOT USE PVC. Trust me. Use something NOT sticky or you will end up wanting to flush your project down the toilet.)
2 matching zippers at least 18" long, up to 24" long. They MUST be separating zippers, and get the sturdiest, chunkiest ones you can find. The ones I used on this example were a little too petite.
Some sort of hardware for hooking the strap on. Or something.
I wanted a bag 11x14x6, so I cut the following pieces.
2 28x15 pieces for the changing pad. One of the outer, one of the waterproof stuff.
4 15x12 pieces for the front/back. 2 outer and 2 lining.
4 12x7 pieces for the sides. 2 outer and 2 lining.
2 15x7 pieces for the bottom. 1 outer 1 lining.
To get started, I separate my zippers and grab 1/2 of each. I do this because even 2 18" zippers are slightly different, and I want each to match up with its own "mate" when the bag's together. I mark the 1/2 point on each zipper and on the cloth.
With right sides together I pin the zipper between the outer and the waterproof stuff.
VERY IMPORTANT: Make sure the "outside" of the zipper is facing the "outer" fabric, not the waterproof.
I do the same to the other side.
IMPORTANT: Make sure the "separating" ends of the zippers are both toward the same end of the changing pad.
I sew down the sides with a zipper foot, staying about 3/16" away from the zippers. I sew up the ends leaving an opening to turn the changing pad.
I turn it right side out and get this:
If you have done this right, you should be able to zip the pad into a long tube at this point.
NEXT INTERFACE ALL OUTER PIECES.
Next I take the 2 "side" pieces, 12x7. I find the center of the zipper again, and the center of the fabric about 1" down. I pin the zipper as shown..dunno how to explain it.
IMPORTANT: Again the "front" of the zipper must face down, so the pull is against the fabric.
Baste as shown around the zippers. This totally sucks to do, you will have to lift and reset the presser foot a lot around the corners, probably.
Now's a good time to put on strap-holder-thingies. Also I have pressed the TOP part of the zipper up and stitched it. DO NOT DO THAT on the sides, but do on the top.
If you want to, now's a good time to put a pocket or something on the front of the bag.
I put one on, then pinned the side onto the front. I stitched along the edge over the basting. Well close enough anyway.
Open it up and see this....
Repeat for the other side.
Sew the bottom on....
I then sewed the back on and put the inside together. As when making any other bag leave an unsewn part in the lining to turn the bag through.
I set the lining in the bag (right sides together of course) ....
Stitched around (broke 7 needles in the process ) and turned it inside out...
Then topstitched around the top edge which looks cleaner.
Zipped the top on and had this:
Ask questions if you have any!!