I have been following the electrolisis thread for the past couple of days and wanted to add something. There was nowhere that an "add reply" was apparent. Is there a limit as to the thread length before it is shut off? When I went to another thread there was an "add reply" on it. In any case since I couldn"t add a reply on the electrolisis thread, I am trying and end run. I took by analog multimeter down to the boat and put one probe on the prop shaft and touched the other probe on the frame member that the engine is mounted on. I got a reading of 20 ohms. I then scratched thru the paint on the transmission side flange and got the same reading. when I touch both probes to each other the needle goes almost all the way to 0 ohms. I put new isolator washers in the prop side flange this year and the isolator washer between the flanges is in good shape. Is the 20 ohm reading bad news? I might add that my boat is not hooked up to any ac, I have a reading on the capac meter of .8, last year it was at .7 and I haven't changed anything. this is a fresh water lake. any thoughts?

Clark: I think I have figured out what happened here. Just a guess - but I think I'm on the right track.
The thread got into a bit of a p***ing match over whether a vendor had posting and discussion privileges and Joe, our moderator, indicated "end of thread" in the last post to, I think, cut off the debate. Just now, using deputy admin privilege, I unlocked the thread for a moment and all the posting/editing/quoting options reappeared. I re-locked and these options again disappeared. Giving way to Joe's superior rank as the heavy-lifter here and the Honored Fellow who set up the site at a great investment of personal time, I am leaving it locked.
Your "end run" was ok because you shifted the discussion a bit and a new thread is in order.

Meanwhile, there's another isolation test. It takes two people. One holds in the Capac meter button to check if the meter deflects when the other runs a probe between the shaft and that bare spot on the hull.

the info comes from an earlier post here in this Electrical & Corrosion section:

PROPELLER SHAFT GROUNDING - Problem: Propeller shaft is improperly grounded to engine or hull. To determine if this is the cause, ground shaft to hull. This can be done with screw driver by touching bottom of hull with point and the shaft with the side of blade. Do this in the area between stuffing box and coupling. If the shaft is not grounded, the meter will deflect downward indicating proper installation. If a grounded condition still exists, disconnect propeller shaft coupling from the engine. If the coupling was grounded to engine, then needle should deflect upwards on the scale when this separation occurs.

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Joel Albert, Potomac MD
"Charlie B" - 32' FBS
docked Deale, MD

Jeff: I re-read the paragraph you quoted. You are right.. the way it was worded after I clipped it from another article, it sounds as if the shaft is supposed to be grounded. No! I re-wrote it to read correctly (I hope). The test to see whether it is grounded is correct.

Repeating to all: prop shafts are isolated, not grounded. Otherwise, bad things happen to boat and your wallet.

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Joel Albert, Potomac MD
"Charlie B" - 32' FBS
docked Deale, MD