Singer 45K93 rust removal

[eddo]

Bummer indeed... just too keen to get movement.  As long as I can get the part off... there are two bolts, and I notice, from what I can see, one at least has a screw slot on its other end (behind that main link arm to the left in the image above. It also seems like I'll have to get it moving to access both bolts which poses a problem given the weakness I've generated

[eddo]

Guys,  I've also found that same link arm part 52165 supposedly on a 95-1... and I have one of these at home for scrapping so might be in luck- just not there for a couple of weeks so will hang in suspense.  Thanks again for leading me in the right direction.

[jimi]

https://youtu.be/I0xx53jufMI see if you can open this eddo....

[jimi]

Yes the 95-1and 95-2 has the same part number #3033 same as the 45k89

[eddo]

yep.. my son has confirmed that the part is there inside the old 95k1... and has also asked when it will be moved from his shed! 

I couldn't open that vid Jimi...?   below are some progress shots. First, the machine out of the oxalic acid bath after 15 hours.. comes out a bit greyish and dulled but major rust gone, paint fine. Then penetrant, wd40 dousing and lots of oil.. Still seized but I've got 1mm of play in the flywheel, so I'm rocking that back and forth every so often..I'll try to coax the needle plate screws off with some heat applied to the plate, and do some gentle tapping... When I get it back home in a couple of weeks I'll probably go the diesel bath route if it is not moving by then. I can't even get the presser foot bar to shift yet. My $100 investment is sure providing me some entertainment at least. 

 

[dikman]

It's looking a lot better than it was! Localised heat/pin-point heat is a good method for loosening stuck screws, along with tapping the screwdriver. A good home-made penetrating oil is auto trans fluid and acetone, mixed 50:50. Sounds like you've got a pretty good idea of what you're doing, I look forward to some progress reports.

[eddo]

OK... so I've now shipped my 45K93 back home to my familiar world of tools, and as it is still well seized after the initial acid bath de-rusting, a couple of weeks of oil, wd40, off the shelf penetrants.. I can only guess theres still some gunk between joints that is not allowing enough movement despite hefty weight, levering and tapping applied the the flywheel. I've been doing a bit of heating, cranking of parts that i can get to (Jimi's vid was useful see what actually moves, thanks...), but I just can't free it up yet.  I've decided that given its shoddy state and the fact that I want a 'user' rather than a seller,  I'm going to give it a lengthy electrolysis bath and see how that goes- even if it eats a bit of metal..  I would appreciate some advice about how to go about this-  I know the basics, and have a low voltage car battery charger, just not sure what to hook up to for best results, given the machine will be complete when it goes in.  Any tips at all welcome.. i.e. what do I best add to the tub to attract the rust, steps on process, timing etc..

 

[Constabulary]

Often the main problem is a seized needle bar. I would loosen the the 2 clamping screws on the NB clamp and apply heat (maybe with gas blowtorch) on the bushings and oil them and try to free the NB with a piece of wood and gentle hammer strikes. Heat and oil will most likely loosen the top shaft too if it is seized.

this was my ".45" project - pretty much the same machine :

 

Edited July 3, 2021 by Constabulary

[DonInReno]

It’s always a good idea to start experimenting with electrolysis by treating old rusty tools and bolts to get a feel for what works and what doesn’t.    If not done carefully you can ruin the entire machine - there is a good amount of misinformation online saying only rust is removed and it doesn’t damage the metal.   Electrolysis is removing metal - the trick is to only remove as little as possible.    Many instructions online over simplify the process and just say hook it up and leave overnight.  The size of power supply and concentration of electrolyte in the water change the speed at which metal is removed by a factor of 10x or 20x.

The chemical process is straightforward - metal is eroded from the negatively charged side and deposited on the positive.    The machine is hooked to the negative and a scrap of metal is hooked to the positive.    Water has to have an electrolyte  of some sort for the electrons to pass - salt, baking soda, lye and any number of substances will work, but washing soda (sodium carbonate) is typically listed as ideal for this purpose.   Lye has the additional benefit of removing paint and degreasing - if chemical burns or worse life altering injuries can be avoided.  In a 5 gallon bucket I just add a roughly measured cup of washing soda.   

The smaller the power supply the slower the process will be - I have a small 12v car charger for longer overnight soaks and a small 115v arc welder that works quickly at 28v and many times the amperage.  

The bubbles given off in the process are flammable so do this outside.

For me, the key to getting the best results is in the size and placement of the positive electrode as well as the negative electrical connection to the machine.    Electricity follows the path of least resistance - if a shaft is frozen and the connection is made to the machines base and the positive electrode is nowhere near the shaft then nothing helpful will happen.   Much better to energize the shaft on one side of the rust and place the positive electrode near the other side of the rust.   This is something you need to develop a feel for by experimenting on other items before using it on your machine.

Rusted/frozen areas need to be degreased prior to soaking - oil is a barrier to the electrolyte.    All the penetrating oil that has been applied should be flushed out as much as possible.   Avoid break cleaner because it can remove paint.   A soak in dish washer detergent and hot water works well to degrease, but will dull the paint somewhat.

Periodically the item has to be taken out and wire brushed to judge progress - it’s unreasonable to expect this to be a simple matter of soaking until it’s all rust free.   It’s aways fun to learn a new tool to use with old machines, but as with many things, this is easy to do, but difficult to do well without practice.

Screws and shafts will still need to be removed with heat - there’s no way around getting a propane torch and developing a feel for how much heat and where to put it.   Honestly, if you really like the machine you’re working on, find a low value rusted up machine to practice on.   As with anything new, it’s always a good idea to not practice on the machine you’re trying to save.

As much as possible try not to put pressure to move one part by putting more than normal pressure on a different part.   For instance if the needle bar is stuck, don’t crank hard on the handwheel to free it up, but rather find a safe way to tap on it directly with a wood, brass or aluminum block of some kind.    

Keep up the good work - we look forward to seeing it sewing again!

 

 

 

[dikman]

A very nice summary of electrolysis, Don.

If you use salt for the electrolyte it generates hydrogen (just so you know). If you run copper wire to various parts of the machine and common them to the negative electrode it may spread the electrolysis effect more evenly around the machine but as Don said it's important to make sure you've got a good clean metal-to-metal contact. A lower voltage may take longer but it will be more gentle, even 12v is considered high by some. For the positive electrode any scrap steel will be fine and using several pieces around the edge of the tub, commoned together, will help given that this is a complex shape to clean.

For something like this the Evaporust-type cleaner would be ideal, as it will not harm any of the metal, only the rust, but unfortunately the quantity required would make it very expensive here in Oz (even the Repco one, at half the price, would likely be a couple hundred $$).

I suppose you could always use a sand-blast cabinet if it's that bad! (Just joking).

Edited July 3, 2021 by dikman