Flooded Motors

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Feb 13, 2017
Whether it was salt water, or just plain dirty from a storm, doesn't really matter. Treat it as worst case, like coastal seawater near a shipping terminal. First off, keep it under clean water until you can put the time in it. Tap water will work, grocery store distilled water is better. But not so better as to justify the cost in a storm area. Just keep it under water, whatever you can get. Rain water if nothing else. As long as air can't get to anything, it won't rust much.

When you start, one piece at a time, dry it with compressed air. No more that 10-15 PSI. A vacuum cleaner was a good call there. Soak it down with WD-40. It can be bought in gallon cans. BTW, the WD in the name is for water displacent. Soak it good, leave it submersed for a day or two if you can. Then again blow it out, 10-15 PSI. Let it stand for several hours, on end if possible.

Baking is the preferred method. But the dipping and baking process will cost more than a new motor for the smaller sizes. Find a spray varnish (such as Grainger) and heat in an oven (just under 212 degrees) to bake the water out and the varnish in. Glyptol is a brand name from my past. I don't know if it is still sold, but is a starting point. You want motor varnish, not painter's varnish. There is a difference.

Once it is dry and varnished, check it with a meggar for greater than a megohm, every coil to ground. If it's a single phase motor, replace the capacitor. Don't bother checking it. Just replace it. Same for the bearings. They may be good, may run for years. Or they may last a couple of hours. Just replace 'em.

This description is from my deep past, on a ship at sea. I think I covered every point, but can't be certain. I have repaired diesel engines since, on boats. But again, a long time ago. And diesels don't have any electrical parts, except the starter. Been a mill electrician for years since. Just trying to remember it all. In the mills, we replaced the motor and let the motor shop worry about the old one. Sorry... ...

Bill Hudson​


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