Saturday, November 25, 2017

Raincoat Part 2

Last week, I discussed modifying the design of a raincoat to produce a garment capable of really keeping the water out.  Now it's time to cut and sew the coat in a way that maintains the waterproof integrity of the fabric.  The fabric is coated on the backside with a polyurethane layer that's waterproof.  The problem is that any holes, for pins or for seams make permanent potential leaks.
To start, the fabric has to be cut without pinning the pattern to the fabric.  That means that the fabric can't be laid out on my usual cutting table, since it's not long enough to lay out all 4 yards of fabric simultaneously.   Fortunately,  I have a piece of floor that's big enough.  The pieces have to be help down to the fabric some way.  Fabric weights can be used for this purpose.
I don't have any fabric weights, but anything small and heavy works.  I found items meeting this description in my silverware drawer.
Some completely new pieces had to be designed -- the storm flaps.  These are not hard to create -- they are just rectangles an inch longer than the zipper(finished dimension).  The right one is 3" wide (finished dimension) and the left one is 2 3/4" (finished dimension).  The pockets are also not like the pattern consisting of a patch pocket and a flap, all of which are simple rectangles.  The sizes can be cut to suit your taste or available fabric.

With all the pieces cut, they need to be sewn together.  It's recommended to use polyester thread for this purpose, not cotton thread.  General purpose sewing thread usually is 100% polyester.  I bought seam stick tape to stick the seams together before sewing.
The idea is that you stick the two pieces of fabric together (no holes), sew the seam, and then the tape dissolves the first time you wash the garment.  The tape did a great job of dissolving on washing, but it didn't do a very good job of sticking the fabric together.  It might work better on other fabrics, but on the nylon, it didn't stick well enough to deal with curves seams.
I did have success with pinning the fabric together inside the seam allowance, where the holes don't matter.  The piece shown here is a sleeve tab.

For any seams where the holes penetrate to the interior of the garment, the seam must be flat felled, then sealed with seam sealing tape.
First the seam is sewn in the normal manner.  Then, all but 1/4 of the seam allowance is trimmed off of one side.  Note that the right side of the fabric is purple while the wrong side is white.
The longer seam allowance is folded over the narrower one and the whole thing sewn again.
Finally, seam sealing tape is put over the seam and sealed to the garment with an iron.  When cold, the tape isn't even sticky.  It has a matte side and a shiny side.  The matte side goes down on the fabric.  Use the silk/wool setting and don't even try to slide the iron on the fabric/tape.
Areas that don't get seams, but where stitching penetrates the garment also have to be sealed, like this small rectangle of Velcro sewn on the opposite side.
To create the pocket, sew a strip of Velcro near the top, then sew two pocket pieces together to create a patch pocket with right sides on both sides.  The patch is then attached to the front of the garment.  Pins can be used close to the edge to attach it before sewing, since the whole thing will get sealed later.  The pocket flap is similar, but it sewn to the front on one side, not three.
The sleeve flaps can be put together in a similar way.  Note that top stitching is necessary to crease the fabric properly.  I had to stitch the bottoms of the sleeves after this photo was taken.

The storm flaps are also attached to the fronts before sewing them to the rest of the pieces.  Attach a full length strip of Velcro to each, stick them together, then center over the zipper (which has yet to be sewn in at this point).

Most of the rest of the garment was assembled according to the directions from the pattern.  The zipper is added when the lining is attached, sandwiched between the outer fabric and the lining.  Those seams don't seam to be sealed, since they are protected by the storm flaps.

This raincoat proved to be quite waterproof.  The day after I finished it, I wore it in a serious rainstorm and I stayed dry.  Careful attention to details and the right materials worked.

Come back next week for more fun with a sewing machine as I start to explore all the fin you can have with fleece.

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