Sew a DIY waterproof zipper bag

As I’ve been talking about laminated fabrics, I wanted to bring them together in this simple DIY waterproof zipper bag.

This little project will give you a chance to practice your laminated fabric skillz, learn how to sew a boxed corner, plus you’ll get a cute bag to hold your makeup or other bathroom goodies.

So on to the project!

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Supplies you need for your DIY waterproof zipper bag

Where to get the waterproof zipper bag pattern

In addition to the supplies listed, you’ll need the waterproof zipper bag pattern for this project.

You can get that when you sign up for my newsletter. Do that below!

Cut out your bag pieces

After you assemble the PDF pattern (there’s 1 piece, that prints out on 2 pieces of paper), cut out your DIY waterproof zipper bag pieces. Use the rotary cutter, especially for the laminated fabric.

You’ll need 2 pieces cut from each:

• laminated cotton
• fusible fleece
• lining fabric

Fuse the fusible fleece

Flip your lining pieces to the wrong side. Place the scratchy side (i.e. the one with the fusible glue) on top of the lining piece.

Fuse the interfacing to the lining with steam and a medium heat. Repeat for the second lining piece.

Now it’s Sew Time.

Make zipper sandwich #1

I’ve talked about making zipper sandwiches before with the 7 minute DIY zipper bag.

Basically it’s a jiffy way to sew the lining and the outer fabric to the zipper in one go. Here’s how to sandwich that zip.

Place the zipper along the top edge of one of the laminated cotton pieces. The right side of the fabric should face the right side of the zipper.

Then stack one of the lining pieces on top of the zipper. Use the clips to hold everything together.

Sew the first side of the zipper

First lengthen your stitch to 3.0mm. Sew with the lining on top along the top edge of the zipper. You’ll be sewing through the lining, zipper, and outer fabric all at the same time. Let the zipper foot ride right along the edge of the zipper–this should be a 3/8″ seam allowance.

When you get to the part where the zipper stop is in the way, lift the presser foot, slide the stop out of the way. After that, you can put the needle down where you stopped and finish off sewing the zipper to the fabrics.

Press the zipper

This could get hairy, so pay attention!

You have to use a press cloth here or you could melt the vinyl coating or the zipper. I’ve melted my fair share of fabric, and I don’t want you to have to deal with that! I talk about another way to press with laminated fabrics in 7 Tips for Sewing Laminated Fabrics if you want to go a no-heat, safer way.

Set your iron to a polyester setting. On my iron, that’s a medium low. Lay the bag as it is on your ironing board with the lining side up. Cover the whole situation with a press cloth.

Next, press the zipper on top of the press cloth, using a whole lot of steam.

If you have a clapper, smack it on top of the zipper while it’s still hot. Let it cool before you move it. The combination of the steam and the clapper will do wonders to flatten out the unruly laminate.

Make & sew zipper sandwich #2

Same setup, second side.

Grab your second piece of laminated fabric and the lining and sandwich the second side of the zipper between the two pieces along the top edge.

Again, make sure the laminate and the zipper are right sides together and the lining is on top of the wrong side of the zipper.

Use the clips just like before to hold everything together. You don’t want to pin because you’ll leave holes in the laminate.

Sewing the the lining on top, Stitch with a 3/8″ seam through all 3 layers. Press this seam as well just as you did with the first side of the zip.

Sew the bag sides and bottom

Your DIY waterproof zipper bag is starting to look like something!

Next, flip the bag pieces so that the right sides of the lining are together and the right sides of the laminate are together.

Leave the zipper open on the inside of the bag.

Sew down the sides of the bag and the bottom of the lining and the bottom of the laminate pieces with a 1/2″ seam allowance.

Leave a hole in the bottom of the lining big enough for your hand to fit through.

Sew the boxed corners

Boxed corners are awesome! They’re going to give your DIY waterproof zipper bag some dimension and keep them from falling over. Here’s how they work:

Open the inner corner of one of the square notched out corners so it folds in on itself. When you do this, the actual square parts will open out into one small straight line.

Sew across this corner with a 1/2″ seam allowance. Backstitch at the start and end of this little seam.

Repeat for the other 3 corners. In total, you’ll have 2 boxed corners on the outer bag, and 2 boxed corners on the lining.

Turn and finish the bag

To finish up, reach through the hole in the bottom of the lining and turn the bag right side out. Use a chopstick or another tool to work out the corners and the top of the zipper.

Press the edges (use that press cloth!) so everything is neat. Be sure to press the hole in the bottom of the lining so that the edges are even with the seam.

Before you slip the lining inside of the outer fabric, stitch the hole closed in the bottom of the bag. Stitch close to the pressed edge.

Slip the lining inside the outer bag. Press it again using that press cloth if it looks a little lumpy as bags can do.

And there you go. You can fill up your DIY waterproof zipper bag and enjoy! Admire all those boxy corners you just made!

You can add a little tassel or a ribbon to your zipper pull if you’d like. I finished mine with ricrac.

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