Singer 15-90 Restoration: Part 3

As you could guess from the title, this post is part 3 of my restoration of a vintage Singer sewing machine. Part 1 can be read here, and part 2 here. Quick recap, I researched this machine ad nauseam, to discover it was in fact a 15-90, made in 1948, and had a removable external electrical system which incidentally needed work. Then in part 2 I removed and took apart the electrical components and was left with a non-powered machine in desperate need of cleaning.

Several good sources for cleaning vintage Singers that I found, the cleaning section of the Vintage Singer Group Handbook which as I have previously mentioned can be downloaded by joining the Vintage Singer Yahoo Group. Also this tutorial on the Quilting Board by Lostn51, here is Part 1. I abhor forums and for the life of me can’t get their search feature to produce the other parts… so good luck on that.

Basically the best and most often giving advice I found for cleaning any vintage black body all metal machine is to use kerosene for the internal and either Go-Jo (non-pumice), Murphy’s Oil or Tuff Stuff for the external. Kerosene is great because it will eat away any dried oil and rust that is gumming up the works without leaving any residue. WD-40 and Liquid Wrench both contain a fair amount of kerosene but have other ingredients that do leave traces and will re-gunk the gears. For cleaning the outside of the machine you need something strong enough to remove caked on filth but something that won’t hurt the finish or the delicate decals. Whatever products you use be sure to test on an inconspicuous spot first! I used a kerosene bath coupled with Murphy’s Oil and the results were fantastic, below is the procedure I used.

First step is take apart the machine. You will need small flat head screwdrivers to do this. I used one like this, that came with my Singer 2263. It might seem daunting to remove all those little part but if you take enough pictures it’s really no problem. Here is an example, this is the bobbin winder thread tensioner assembly on the machine and taken apart:

In this way you will be able to id all the parts without notes, I think I ended up with around 100 pictures once I had the machine apart. Here is a list of the things that can/should come off the 15-90 machine:

  • Remove machine from cabinet
  • All electrical components, plus the drive belt and bobbin winder tire
  • Needle clam, thread guide, bed slide plate and throat plate
  • Face plate:

  • Tensioner
  • Pressure regulating thumbscrew, the large screw that is visible in the upper left hand corner of the first picture of the face plate above
  • Hand wheel, and bobbin winder, the right hand picture below shows the hand wheel off and the bobbin winder screws exposed

  • Bobbin winder thread tension assembly
  • Rear inspection plate:

The only problem I encountered in removing things from the machine were the little screws on the stitch indicator plate:

They would not come off, I dribbled some kerosene on them and still they would not come off so I let them be.

Here is my machine torn down and ready for the kerosene bath:

For the kerosene bath I used a bucket with about a gallon of kerosene and soaked one end of the machine then the other. I also threw all the items I removed from the machine into the bath except the sliver metal parts like the rear inspection plate. Here are some shots of me going to town on the machine with an old toothbrush:

Here is the 15-90 totally scrubbed and drying on a towel, you need to leave it for a couple hours to insure all of the kerosene has evaporated:

As you can see the kerosene does a fantastic job removing all the rust and loosening all the ground-in grime. Here are all the components I soaked in kerosene drying:

Before starting the reassembly I used Murphy’s Oil on the body of the machine, the kerosene just unsticks the grime it still needs to be removed. Here is an example, this is the piece that bolts the motor onto the machine, left is after kerosene and right is after the oil:

The only spot on my machine that I couldn’t get as clean as I wanted was under where the motor sits and where wire insulation had melted onto the body of the machine:

I suppose I could have chipped away at it but it didn’t seem worth the risk that I would damage an even larger area and besides it will be covered with the motor once it’s back on.

Below are my large or plated components getting polished and my machine reattached to the cabinet.

Once everything is satisfactorily polished it’s reassemble time! From my experience this is the time to go slowly and work backwards from the pictures you took to get everything back together. I found that it was easiest to divide all the screws and plates and pieces into piles based on where they go which made it easy to find the correct part quickly. The only problem I had was the tensioner, which I removed by removing the screws instead of unscrewing the thumbscrew and which I can’t get back on the machine. However I have been working on a solution and will post on that soon.

I am very pleased with the results, below is the before and after of the backside of the pillar… it doesn’t look like the same machine!


Here are the beautiful after shots of the completely polished machine:

These three pictures show from left to right the right corner of the machine before cleaning, after kerosene and after polishing:


The next step in refurbishing this machine will be fixing the tensioner, oiling and threading to see if it sews without power.

Anyone attempting to clean/refurbish/take-apart a class 15 machine like mine, I am no expert but I am more than willing to puzzle out whatever problem you are having with you just let me know!

UPDATE: How to Clean & Restore Vintage Singer Sewing Machines the eBook is now available in the Zounds Shop! Save and print all of the information you need to fix your machine! 

More to Read!


  1. Nornerto Souza says:

    Very usefull. I’m doing it now but mine is a 15K series that was my mom’s threasure. Here in Brazil was manufactured about the 60’s by Manoel Ambrósio Filho S.A. The name is “Princeza” where normally is “Singer”. The user’s mannual I can’t find in the Internet. I Think that the number code is 15CH1B and the letter “B” is Brazil. Am I right?

    Thanks and Congratullations.

  2. Andrea G. says:


    I get the feeling that I will be traveling down this exact same path in a few weeks.

    Two days ago, my mother-in-law gave me her Singer from 1948 in the cabinet. It has NO instruction manual, and she said she used it and it worked well… 30 years ago. It’s in pretty rough shape. I don’t have the exact model number, but I have narrowed it down to a 1500 series. I think it’s either a 15-90 or a 15-30 (my serial number is not that much later than yours in the AH line, leading me to think it’s a 15-90 but I’m waiting on Singer to verify).

    Anyway, thank you in advance for your detailed guide as to how to proceed disassembling, cleaning, and reassembling the machine. I have *never* done this before at all, and if I’m honest, it’s a bit overwhelming.

    Thanks again,

    • I’m so glad my posts are helping/will help you. I am still in the middle of restoring mine, working on the electrical right now. If you haven’t tried this website: you should it’s how I identified my machine. I know what you mean about it being overwhelming, but don’t worry I had no prior experience either. It really isn’t all that hard old machine like these were meant to be repaired at home!


  3. Mike E. says:

    I’m so happy I found your blog! I was recently given an identical model, same year and same cabinet. I’ve never done anything like this, so your article series is really helping me out in the restoration process. I took a risk and plugged mine in, it turns on and works fine, an amazing feat after who knows how long sitting in a dusty garage.

    Have you done any work to the cabinet? Mine is pretty beat up, the thin wood on the top cover is peeling off and needs to be replaced. Just wondering if you have found any resources concerning the restoration of the cabinet itself.


  4. Andrea G. says:


    Thank you for your reassuring words. I went to that website and that’s how I narrowed down the models to those two. The main problem is that when I slide open the plate and look at the bobbin case, mine doesn’t look like either of those.

    Let us know how the electrical works out!


  5. angieclaus says:

    So, I have the exact same machine… and have been using it for about a year. All of a sudden the thread got jammed up, and it started to run on its own. I’ve had to unplug it to get it to stop! I took apart the whole shuttle assembly to make sure there wasn’t a bad thread jam in there, and cleaned out what was there, but it’s still freaking out!

    After reading your series, I’m wondering if it might be an issue with the lectrical, and upon very basic inspection, there are exposed wires, so I’m thinking of tackling that rather try to find someone to do it for me 🙂 How did you know it was just the exposed wiring causing your issues?

    Also, I am completely missing the bobbin winding mechanism… where did you find yours?

    • Thanks for your question! I’m no expert, but here is a jumping off point. The 15-90’s are unique in that the electrical system is 100% separate from the stitching mechanism. So to isolate the problem, try to sew on a scrap of cloth by just turing the hand-wheel. If it sews fine, then your problem is solely electrical. If it won’t sew then you have both an electrical and stitching mechanism problem. 🙁

      Exposed wiring is a concern for a number of reasons anyway, so that should be a priority to fix in any case. To answer your other question, I’m not sure what you mean by bobbin winding mechanism. I only needed a bobbin winding tire to complete my winding assembly. If possible send me a picture of your machine so I can see what you mean, my email is Let me know how it goes!


  6. Kellie Burns says:

    I’m currently restoring my singer model 66. How long to you leave the machine head in the kerosene? The machine is very dull and dingy looking. I’ve heard to be cautious of the kerosene removing the ornate decals on the head. What should I do?

  7. MarshaLaw says:

    I am cleaning up a 1936 15-91 model that I just bought. Of course, I took the bobbin winder thread guide apart and forgot to take pictures. Oops! Thank goodness I found your blog and your photo helped me put it back together. I’ve been using WD-40 to clean the insides because I have no kerosene on hand. But I should be ok, right? … Going to keep camera on hand from now on so I don’t muck up something really important.
    Thank you!

  8. Estevan Atkinson says:

    hey there. Just picked up a 15-90 and it worked for a second now the motor just spins and the hand wheel is not turning with it. The metal piece in the middle of the hand wheel is really needs a good twist for it to move the needle up and down. It just makes a buzzing sound and the machine doesn’t work. Have any ideas?
    The machine has not been ran in years.
    All electricity works.
    the motor spins.
    it worked for a second but stopped after the lady put the needle through the electrical cord (yikes).
    Any information would help!

  9. Chelsea says:

    Hello! I am trying to take apart clean out and oil my grandmothers singer sewing machine, i have no manual and from a ton of internet searching i’ve come to the conclusion that it’s a electric 15-30 model although I am not positive but that seems to be the closest resembling model. I do know it was made in 1937 its serial code starts with an AE. Anywho I would like to know if anyone can point me in the direction of a tutorial for taking it apart and a service manual. I’ve been trying to remove the face plate but the screw does not want to budge, I’ve been spraying it with liquid wrench for the past 3 days and its still not moving although the screw is now very clean =P Any advice on how to take it apart would be great and any tips on how to remove this unruly screw without stripping it would be great thanks!

    • Here is a link for the operation manual of your machine:

      As for the screw… on my machine there were several screws that wouldn’t come undone until it was dumped in kerosene and soaked for a while, there’s probably just years of WD 40 holding it on. I would use a cotton swab with kerosene or just leave the faceplate on for the bath.

      Good luck!

      • Chelsea says:

        Thank you very much for the quick reply I actually came across the original manual hidden under a bunch of stuff inside the stool to the sewing machine, Turns out its 15-86 and Also after a lot of liquid wrench and finding out from more looking around online that using a regular flat head screw driver wont really work all that well but using a hollow ground flat head which is meant for machine screws should work. Got one of those and with the first try the screw came off! So now I’ve cleaned everything scraped and wiped and oiled every nook and cranny She’s looking beautiful! gave her a test last night gonna have to adjust tension but other than that she’s purring =)

  10. Marta Gonzalez says:

    Great tutorial! I am starting my project of restoring a 1936 15-90 Singer machine. I will follow your tutorial closely, I’m prepared to start taking photos. My question is: how did you clean the silver metal parts? My machine’s are really dirty and I wonder if the kerosene is the solution or if there is other products that would do the job.
    Thanks for your very helpful blog.

  11. Nancy fisher says:

    I have a Singer featherweight 221-1 that I need to clean. What did you use to polish the silver metal parts? Did you wax the machine after you were finished? Were the gears and other parts of the machine left inside when you soaked the machine in the Kerosene bath and how did you clean them?

  12. julie wilkns says:

    This is a very interesting post. I have only just discovered the 15 series of machines. I have been sewing on 66 singers for so many years, because that was what my grandmother had and I have it now. Somehow I had never read about the 15-88, 15-90 and 15-91 but I found them on eBay then looked them up and read about them. This is the machine I should have! For it’s time, it was innovative, having dropping feed dogs for quilting, and reverse stitch, neither of which I have on my 1906 singer 66. I love that the singer 15-90 has the ability to sew electric, or treadle, which I prefer, but also it can be a portable (albeit heavy) and I can take it along when I want to. I am looking for one now. I am leaning toward one that is already restored including electrical. But I am proceeding slowly, because I’ve been burned on eBay a few times by untruthful sellers.

  13. hardy says:

    Many thanks for all these information. Based on your report I used Kerosene for cleaning and I am absolute happy about the result, mechanics looks brand new, machines run smooth.
    My problem is to get the grey dirt removed after Kerosene was drying. Meanwhile I found “Murphy’s Oil” available in my country at Amazon, ordered it just now 🙂

  14. Kathy says:

    I was wondering if the shellac on your machine was crunchy? I have shiny black under some gook I thought was just gook but was told it may be the shellac that has gone bad or crunchy as I like to call it. Would kerosene take care of it?

  15. Jane Low says:

    Wonderful information. Thank you. I have one question. When using murphy oil on the machine does it buff dry and shinny or does it leave an oily substance that may stain fabric when sewing. Do you use it full strength or dilute it

    Thank you for all your direction

  16. ROBERT D SILER says:

    Hi, my name is Robert and I have a similar machine as yours and an wondering how long you left the machine in the kerosene?

  17. Robert says:

    Thank you for the information it has been really helpful. However I do t know how long to let the sewing machine sit in the kerosene. An gnome directions in this regard would be really helpful.

Leave a Reply

Your email address will not be published.