This post is a little PSA (Public Service Announcement) regarding that bottle of sewing machine oil you have next to your machine. If it looks like the one on the right, DON'T USE IT!
I have been happily using that bottle, which came with my longarm, since I got it. The oil isn't sticky, it seems to lubricate fine, so why replace it? Well, yesterday I decided it was probably about time. I was picking up one machine from the shop, spotted the oil and picked up a new bottle - the one on the left. See how crisp and clean it looks?
I have been fighting with my machine for ages. Every time I oiled it, the tension would be a mess and I'd have to fight with it to get it back in line. Rethreading didn't work. It didn't matter if it was a new bobbin or a half-full one I'd just pulled out. Every time I oiled the machine, I had to work at it to fix the tension. It would start like this. See those little eyelashes?
But eventually it would fix itself (sometimes with a loud snap) and I'd be fine until the next time.
I took it in for service, and they couldn't reproduce the problem. I finally resigned myself to this being a 'feature' of my machine that I would have to live with. Oiling was relegated to once only, as I started a quilt. Not a good policy, since the norm is to oil every 2 bobbins, and a large quilts takes upwards of 5. But it was working for me, somewhat.
But today I had fresh oil, so as I loaded my next quilt I used it in my longarm - precisely one oiling of the bobbin race. And I could not believe the difference! Not a SINGLE issue with tension. It was beautiful, and the tension never flinched.
So the moral here, ladies and gentlemen, is don't keep using that discoloured oil in your machine. Invest in fresh oil as often as necessary (a whole $5 this bottle cost me). You might not realize what's happening, but your machine will thank you.