Your video was very interesting, informative, and well done. You mention cleaning the bobbin case. I checked mine and it was very dirty. I cleaned the lent out but there was stuff sticking to the bottom and sides. Not real bad but needs to be cleaned out. Can I clean the case out with alcohol? I'm having trouble getting the bobbin thread tension right. Could this be causing my tension problem? my machine is a singer 15-90 regular sewing machine. Thank you for this video.
You can use Isopropyl Alcohol (91%) from Walgreens or CVS. If you place it in a bottle with a squeeze nozzle, you can aim a large stream right at gunk. Put a plastic tupperware underneath to catch excess. Tweezers holding scraps of blue towels can scrub the hard to get areas. Check under the tip of the flat spring and anything it touches for trapped gunk and cardboard, and spray/pick it out. Don't forget to remove the thread or anything soakable first, wipe all excess alcohol when done.
