I'm writing this blog post to coincide with the impending release of my next pattern - the Akerfeldt Coat. This pattern is finished with flat felled seams and there are some areas in which these seams are folded over, or meet another seam and it creates a fair bit of bulk. Not a good time if you're unprepared.
An industrial sewing machine is the preferred choice for sewing this pattern. But fear not. The following tips should get you through on a domestic machine with minimal broken needles and swearing.
1. Use the appropriate needles for your fabric.
Most sewing needles packages will state what kind of fabric the needle is suitable for. But if it doesn't, a rule of thumb to remember is the larger the number, the larger the needle.
Look for needles labelled as 'Jean' or 'Heavy', as these have a sharp point and strong shank, suitable for heavy weight fabrics. Or needles with the numbers 90/14, 100/16 or 110/18.
2. Choose thread suitable for the garment
When using heavier fabrics, such as canvas, denim and oilskin, you will need a durable thread to match. I've recommended upholstery thread in the instructions for the Akerfeldt Coat, but you could use any kind of thread that's stronger/heavier than the general 'all purpose' thread.
3. Machine Foot
You may like to use a speciality foot for this kind of sewing.
A walking foot that allows the top and bottom layers of fabric to feed through at the same rate.
A Teflon coated foot, that allows the fabric to glide through easily.
A roller foot to help the feed dogs move the fabric under the foot.
4. Hammer your seams
Pretty straightforward. If you're hemming a garment and worried about getting your machine foot over the doubled up flat fell seam, you may like to give the bulky area a good whack with a hammer or a mallet first. This will help break down and flatten the fibres, allowing the needle to penetrate all the layers more easily. Sandwich your garment between some scrap layers of fabric before hammering, to prevent too much damage.
4. Machine Foot Tricks
I could try to describe the following machine foot hacks, or I could just direct you to these two great short videos that will do a way better job of showing you.
Credit: Baby Lock Sewing Machines
Credit: Spencer Ogg
I posted this video because, 1: I adore the way Hump Jumper is pronounced here. My Aussie accent would make a meal of that. And 2: this could be made out of things you have lying around the house - cut out cardboard etc. Genius!
5. Using the handwheel when you get to the bulkier bits.
I've broken many a needle flying over seams at a vigorous pace. Slowing down and turning the handwheel manually can help prevent this. You can feel it if the needle is resisting going through the layers when you do it slowly and halt progress, preventing needle breakage. If there is resistance, you might have to refer back to the previous tips if you haven't done so already (hammering seams etc) or your needle may be too blunt.
Some other things worth mentioning to help make the sewing process easier are grading your seams and slightly lengthening your stitch length (I usually have mine on a 3, but I change it to a 3.5 for heavier projects).
Hope this helps.