I used a magic eraser on my motorcycle pipes to remove some plastic that got melted & then burned onto them. I was tentative about using it, not knowing if it would leave scratches, but it didn’t. I’d be Leary of using one on a painted & finished surface. Wow-using one on a child?!? Who would think that’s a good idea?

I think you mean 'rubbing compound'? That might work well. I hadn't thought of that. If you want something a bit gentler to try first, there's clay bar. Clay bar will take off a lot of surface problems without harming the paint. We use it on the cars all the time to remove surface contaminants without harm to the paint job. You'll also need a detail spray to use with it. It might be worth a try.

As far as it being rust goes, that's possible. But rust coming up from underneath so it shows on top often bubbles. That's hard to mistake for anything but rust.

I found some info on magic erasers here: https://www.yourmechanic.com/article...r-by-kevin-woo
Quote: "Magic Erasers are made from melamine foam. When a Magic Eraser gets wet, its abrasiveness is the equivalent of 3000 to 5000 grit sandpaper, depending on how hard you scrub. That might not sound very rough, but on car paint the damage could be severe. Worse, if you have a heavy hand and go to town with a bone dry Magic Eraser, it would be similar to using 800 grit sandpaper. In either case, using a Magic Eraser to clean a spot on your car (or in this case, sewing machine) will scratch the paint."Here's more on melamine foam from Wikipedia: https://en.wikipedia.org/wiki/Melamine_foam

I don't have a clue what those spots are on that machine. Is it also on the other side, do you know? Since the back would be the "up" side if the machine was in a cabinet, the discoloration could have come from exposure to something while in the cabinet if it's just on one side. Is it a cast iron or aluminum machine? If there is an inconspicuous place, you could carefully try a tiny spot of rust remover like Must for Rust and see how it affects the paint. Or have you tried the old cleaning standby: sewing machine oil?
Andy Tube channel on YouTube has some good advice on using automobile cleaners and waxes on sewing machines.
It's a nice machine, hope you can make it look all nice and gleaming again!
MJ

I am terribly sorry for bumping an old thread like this, but If anyone could give advice I would be grateful. See, I have been selling these old sewing machines and many times I had problems with mold. Some people let these rot in some shed, and they do not know that there is money to be made of them. A Few months ago I found an old model and I tried cleaning it, but mold just comes back the next day. I found an article online where they are talking about mold and in one part of that article they say how there are professionals that can get rid of it. I really have tried everything, if I do this and it does not work I will lose money. Does anyone have experience with companies like this, will it work?

Can professionals get it off?

When we bought this place, it came with a truck because the owner had died and no one would claim the estate because they were afraid he had debts all over town. We live in a rain forest so after 3 years, let your imagination run as to how much mold there was inside. My husband started researching because the truck was worth $5,000. - $10,000. Well vinegar kills mold. He has sprayed the whole interior. Now I must admit I have not been in it but his son said it is fine. There is no evidence of new growth and we have had lots of rain and temperatures done to freezing. He said mix the vinegar 1/2 and 1/2 with water. Don’t know if this could get under the paint and if you let it sit for a period of time I don’t know if it would damage the paint. Vinegar is an acid.
Good luck and please let us know how things turn out.

You will probably have to polish it off with a fine auto polish or plastic windshield polish. I have rubbed out a lot of stuff like that with car wax or cleaner. As long as you don't have decals on the machine you can rub them a lot.

Like everyone else I believe it is mold of some kind. This machine looks like it might need a total restore to get rid of this. Is the machine in running condition?

There are so many machines out there that machines in this condition is no more than parts to myself. Would be different if it was a rare model. Definitely not worth the work with so many similar models widely available https://cdn.quiltingboard.com/images...es/thumbup.png