Now I am almost sorry that I asked this question. (JK) Even so, not sure what I will do about my presser feet .... up or down .... just not sure what to do. I wasn't thinking that the spring would weaken but would maybe become permanently squeezed somewhat (so to speak) more than it normally would be and therefore would not hold the foot down with as much pressure as much at it used to or should. Not so, SteveH? I would have to defer to your expertise as you appear to be the knowledgeable one on metals and old machines. At least you have certainly had a whole lot of experience base on all the info. in your posts about things you do and are into.

Will have to think about this but I am certainly leaning heavily toward leaving the foot up as per several of you experts in vintage machines have said to do. You have worked with, cleaned, and used more old machines that I will ever see so I guess that is the best way to go.

I started an experiment on Wednesday.

I took three matched springs
measured the lengths (1.25")
left one alone
Put a skinny bolt through one with a washer on each side and a nut to compress it to .75"
secured the end of the third and stretched it to 1.75" and used a nail to hole it stretched

It is up in the rafters now for 6 mos.

We will see if after 6 mos I feel like (or a need) to extend the test to a year or more

A more accurate test would be spring tension testing, but our pull tester at work is calibrated and set up for our small medical tools we make, so I can 't use it for playing

SteveH, I for one will be interested in the outcome of your testing. Thanks for doing this. Now if I can just survive for the next 6 months ....... thankfully I am not in Boston! Yikes!

As a side note, it is not a good idea to leave thread in the spools. I have several long bobbins and most have been rusted because of thread left on them. The first thing I do is remove the shuttle and check for thread on the bobbin. Then I pull the thread off and give it to the birds.
Helen Ann

I've seen that, too - I pull off the thread then soak the bobbin in some vinegar then use some foil and brush off the rust. Get them good and dry and they should be better than the new ones you can buy.