I was asked what to do with corrosion on the attachments that came with our Featherweights?
I've gone so far as to sand blast the attachments. Where the corrosion was the sand blasting removed it but it took it down to bare metal also ready to rust and they did not look very good. But the main problem was that the sand of the sand blasting process, we used a very fine grade "medium" (as it is called), will get into everything and I still can't get the rufflier to work without grinding and grating. There are parts of the ruffler that can be removed by removing a screw or two and this will give you access you didn't have as a complete attachment.
Use your digital camera in its macro-function (close-up function)and get a picture of what you took apart to help put that puppy back together, or is a thing that is common to me alone.
Steel wool in a four ought grade (0000) will do a pretty good job where you can reach the corrosion.
Navel jelly doesn't do what we desire, it will leave a pitted surface that isn't much of an improvement over what you started with, but it isn't reddish any more!, it's more like black.
There are small rock tumblers sold (harbor Freight) that with a fine garnet based medium (or sand box sand)will clean the attachments and remove a lot of the corrosion but the cost will be about $40 if you do not have the small rock tumbler plus the medium and you could buy three replacement attachment sets on eBay for that. If you use the rock tumbler you must use enough medium to pretty well fill the tumbler with your attachments added. You do not want the contents to tumble without sufficient sand falling onto each other causing damage. They slide about in the sand and gently abrades the corrosion off. Then clean the fool out of the attachment to get the medium (grit, sand) out of them and oil them. Even the parts without moving parts will like a film of oil to prevent rust in the future.
Any method you use will leave your attachments prone to rust so don't leave them in the bathtub any more.
The best thing I've done to come up with a great set of attachments is to look for a replacement in good condition.
The main cause of corrosion in our attachments is the same cause that made the and make a Featherweight case and machines smell not so pretty good. Newer designs in machines came about and people wanted the new machines that zig-zagged and had six other built-in stitches as well. Our Feathers were relegated to the basement or the shed and after 20 years of "temperature controlled storage"..............well..........
From the methods above I would suggest the four ought steel wool (0000)for most applications. I would suggest the use of a rubber glove on the hand you hold the steel wool in as you can get very fine slivers that will bug you.
Source: Dave's Blog