electrolytic derusting of a bearing?

I have an old (antique, really) scissor jack, maybe from the 1920s or earlier.
It's really very well made and (after a little elbow grease and Kroil) moves
smoothly still. It is driven manually with an Acme threaded shaft. For raising
the load, the shaft has an integral boss which bears on a thrust bearing. This
thrust bearing is heavily built and, after soaking in Kroil, turns still but
to call it crunchy is an understatement. After pricing replacements (in the $20
range) I'm wondering if maybe I can derust this thing chemically somehow. Sure,
its balls are pitted, but this runs very slowly under manual power so howling
isn't an issue. I only know of three ways:
1. direct etching using an acid, which relies on the acid eating the rust faster
than the base metal
2. passive electrolytic derusting using lye and a chunk of zinc
3. active electrolytic derusting using washing soda and electricity
The idea is to be cheap here. I have a variety of containers and all of the
raw materials to do any of these but I'm against #1 because I haven't had good
luck with it. I suppose I could try the old vinegar and salt trick, too.
Reply to
Grant Erwin
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Dig ditches for minimum wage for a few hours. Take the $20 and buy a bearing.
Sorry -- I'm grumpy this morning -- try "do whatever seems the funnest".
Reply to
Tim Wescott
Loose bearing balls are pretty cheap, so I wouldn't bother trying to clean them. I've improved the smoothness of a non-critical and unobtainable thrust bearing by spinning it with grinding compound in the races. An arbor in the mill spindle provided the rotation and down pressure. Use the old balls for the lapping operation and then replace them with new after all the compound is removed.
Ned Simmons
Reply to
Ned Simmons
If I dug ditches and scraped up $20 I'd spend it on something else besides this old jack. Sometimes I just try to do something "on the cheap" - I think this attitude, uncommon in this throwaway society, is still worthwhile.
I cleaned the bearing by boiling it for a few minutes in dishwashing detergent. That seemed to free it up some, still very crunchy. I am trying it in vinegar and salt. Tomorrow morning I'll post the results.
This bearing doesn't come apart, period. I put 5 tons of force on it, didn't even blink. I'd have to destroy it to replace the balls.
Reply to
Grant Erwin
I vote for the electric method. Sure, I've never tried it. But, the information I've read thru this RCM makes me very interested. I suspect you have all the components neded to electrically de-rust that bearing. But, if there is any part/component you need to build a system for electrically de-rusting that bearing, and you do want to try, I'll send you any part you need. I have way too many "good things", and need to distribute them to actice users like you.
Reply to
Jerry Martes
There is option number 4, though it's not a cheap option -
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I recently got some of the stuff to try and it is amazing. Parts come out with a black haze like the electrolytic process, but it can be rinsed away with water. I had to chucks, an old 1870 something, and a modern ball-bearing chuck that where frozen from rust. Twenty-four hours later I could get them to move freely.
Hope this helps
Grant Erw> I have an old (antique, really) scissor jack, maybe from the 1920s or > earlier.
Reply to
Vince Iorio
Grant cleaned up the bearing with detergent. It was still crunchy.
For cheap, you can definitely hook it to a battery charger for a while. And you don't have to go buy washing soda. I've used salt. Talk about cheap!
Doug Goncz Replikon Research Seven Corners, VA 22044-0394
Reply to
I gotta say that if that stuff performs as advertised $21 a gallon ain't that much.
Reply to
Rick Cook
Does it have sand in the bearing ? That might be the 'still very crunchy'.
I'm with you on the fix it on the side for cheap!
Reply to
Martin H. Eastburn
Yeah, that's why I suggested blasting with beads. It will often improve surface finish, especially on heat treated items where it doesn't cut the surface away. . The beads have a nice peening action and tend to blend out any sharp edges ever so slightly. I wouldn't suggest such a thing under normal conditions, but for this application I can't imagine it wouldn't slightly improve the bearing. Cleaning it well after blasting would be ultra critical as would lubricating it. Bearings often feel terrible without lubrication.
Reply to
Harold and Susan Vordos
Why not try flushing/packing it with heavy grease since it is slow speed. Run it a bit and flush/pack again and saee if it smooths up. Flushing while rotating would be best.
Reply to
Nick Hull
OK, I gave it about 18 hours in vinegar and salt and rinsed it in hot water really well. Now it turns quite freely, although it still feels crunchy. I think that if I pack it with heavy grease it will be usable.
That's another McMaster order I didn't have to do!
Reply to
Grant Erwin

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