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That is so upsetting! These machines are so forgiving but there are limits....So glad you didn't take his advice.
This happened to me too---one shop owner who services Singers told me that Singer did not make the grease any longer and to just use the oil. The other shop owner in our area was quite disturbed that I was told that and ordered a tube for me---this was for my recently purchased featherweight. I emailed Singer and asked them what is the right way to care for my fw and reported the one shop owner. Well, after I left the 2nd shop, he called the first shop, since they know each other, and they got together and instructed each other on what to use on what machine. Now they both learned something and Hopefully I saved a lot of others from heartache. My rule, follow the directions in the manuals unless the manufacturer tells you otherwise.
That is really, really sad. That guy has probably doomed dozens of machines to untimely demises.
As for filing the complaint with Singer, I think most people don't realize this: The current-day company called Singer has practically nothing to do with the Singer of old. The original Singer was broken up in the '80s and the brand-name was passed around between a couple of buyers, until a holding company finally bought it and start selling cheap, made-in-China plastic junk under the Singer name.
There is absolutely no connection between the modern-day "Singer" and the Singer Sewing Machine company that made the vintage machines we all love. The marketing people at the new Singer like to pretend it's been one continuously-operating company, but that's not the case. That's why, when you call the company now located in Tennessee to look up a serial number, they don't know any more than you do; they're looking at the same websites we are to look up a model number.
Vintage Singer Sewing Machine Blog
I bought it at Joann's in Lawton, ok 3 weeks ago. I was working on my singer 15-91 this week and was going to grease the pots on it. imagine my surprise when i finally got the screws off and found thick black grease in it.I guess some one needed to grease it before I bought it and this is what they used.
Consider using Marvel Miracle Oil, sold in Walmart, etc. It was developed as sewing machine oil. It works perfectly. The company couldn't make money in sewing machines so they sold it as a gas/oil additive. It works great and it's cheap!!!
Singer lube ! Thanks Joe! You may have just saved many a machine!