Cleaning yellowed machines

[MissMagpie]

I wonder if anyone can give me any advice on cleaning old sewing machines that have gone yellow with age and sunlight? I've just bought a 30-year-old machine that's in great condition, but unfortunately the housing has gone very yellow in places. It's only on one end and along the top, so it's apparently the effect of sunlight rather than smoke or any other kind of dirt. The affected parts appear to be painted/coated metal rather than plastic. I haven't yet made any attempt to clean it.

I know about whitening yellowed plastic using peroxide hair developer, and placing the item in the sunlight inside a clear plastic bag, and I'm planning to use this method (when we get some sunshine again!) on the plastic carrying case, which has also gone yellow.

But what about the machine itself? I wouldn't be keen on covering it with the peroxide cream as some of it would be likely to seep inside around the edges; and the whole process of putting a very heaving machine inside a thin plastic bag without tearing it, and then leaving it in direct sun, seems pretty doubtful to me. Or am I supposed to take the machine apart (not tried that before), and just treat the affected sections separately? Would it even work on the metal parts? Or is there something else I can use?

I've tried to find information on this online, but not discovered anything specifically about yellowed painted machinery (as opposed to separate or easily removable plastic parts). Any guidance would be very much appreciated!

[KayK]

Just have a go with some T cut or car polish if it's a metal part, in a fairly hidden part to start with.  I have had some success with this on much older, all metal bodied machines.  I doubt that it would restore the colour completely, but it sure would make it smooth and shiny.  Use the T cut first, then polish.

[Greybird]

I don't know if this is of any use for your purposes, but when I painted my front door I wanted to paint over the badly yellowed PVC that surrounded the glass panels. I researched the method of preparing the plastic for painting and cleaned it with acetone (which I got from Ebay). I was astounded at the result - it instantly came up bright white. You could try this on a small hidden area first to make sure it doesn't harm the finish,  it didn't appear to damage mine though.

[wrenkins]

Be very very careful with acetone. The u in uPVC stands for unplasticised. Most plastic type finishes won't like acetone one little bit.
Top tip about the windows @Greybird. Some on my town house are really manky grey and I have tried everything...or so I thought.  :thumbsup:

[MissMagpie]

Thanks everyone for the advice!

(By the way, @wrenkins - I thoroughly agree with your motto! I have heard it before, but I don't know where it comes from... do you?)

[wrenkins]

I got it from one of those clever calendars with a daily motto @MissMagpie . I have watched several people poisoning themselves... I've no idea where it originated but I seem to say it a lot. 


Malachy McCourt. A very wise Irish man it seems. Most of them are half wise!!! 

[MissMagpie]

I know we are getting off topic now; but you are so right about people poisoning themselves through resentment... meanwhile, the object of the resentment is in most cases just getting on with his or her life!

[rubywishes]

Totally off topic as I have no experience in this area but just wanted to say....I like being resentful! :thumbsup: LOL

[wrenkins]

My him indoors was resenting me for about a year over some throwaway comment I'd made. I had no idea, I don't know what I said or how I said it, in fact I can't even remember the conversation. Silly old fool has been festering and pi$$ing vinegar all that time. He brought it up just before lockdown and I looked at him as if he'd lost his mind! If it had been the other way round I'd have asked him at the time, either argued or not depending what was required and it would have been done and forgotten. What is wrong with people?
Step up and ask me. I'll tell you! 

@MissMagpie how's your machine looking? You could perhaps try Solvol Autosol. It's like magic potion for most things (kind of like Germolene for machines). Again try it firstwhere it won't be seen.

[KayK]

I second Autosol!  Brilliant stuff!

[wrenkins]

I can't believe I've never tried it on my middle-aged Singer. It brought my 28K up like new.  I might just have given myself an afternoon job! 

[Wychall]

 The yellowing of plastic machines from the 60's and 70's is due to UV action on a fire retardent (bromine) which is added to the plastic. The discolouration is not just on the surface but goes deep into the plastic. There is a method to whiten the plastic using hydrogen peroxide and UV light but it can have less desirable side effects, and is only temporary. Re-yellowing can be slowed by using a UV blocking acrylic laquer but again there is no definitive proof of how effective it would be.
If you are interested in trying the process, Google for Retr0Bright. There are numerous articles about using the process on computer cases.

[MissMagpie]

Thanks again, everyone!

I’ve been looking into Retr0bright—funny how it sounds like a trademark, when it’s something you have to mix up yourself!

Literally never heard of Autosol. Will definitely try that too.