Waiting for the zinc to fully dissolve has two problems.
First, as the zinc becomes smaller and smaller it will protect the other metal parts of the system less and less--including the brass plug which will dissolve very quickly once the zinc is gone. When that happens it breaks off when you try to remove it, and you have a mess to clean up.
Second, it will not actually all dissolve. That white crud you see in the plug is no longer zinc, but various insoluble zinc salts.
Anyplace that sells the zincs will also sell the plugs, they are not hard to find.
Finally, if the zinc is that far dissolved, you are waiting MUCH too long to change it. Shorten up the maintenance schedule for it. You should be changing it when the zinc rod has lost 1/3 to 1/2 of its original size.
---In amelyachtowners@..., <no_reply@...> wrote :
Hello to all.
Recently, I went to change the zinc on the Onan Generator, and when I unbolted the plug, I found the old zinc corroded in place. At first I thought I would drill it out and replace it with a new one. Then the thought occurred to me, “why not just wait until it dissolves on its own”?
Any thoughts or recommendations would be appreciated.
I also wanted to pass along some information.
Recently I began to have trouble with an old Raymarine RL80C Chart Plotter. I contacted Dan Gerhardt who had been recommended on this forum, but he doesn’t repair chart plotters. He recommended I call Steve Senft at Jaytron in Florida (steve at marineelectronics dot com - 941-748-1941). After trouble shooting things on the phone with him, I ended up sending the unit to him. Unfortunately, after spending a number of hours on it, it was determined it was too far gone. However, he sold me a used unit he had in house for about the same cost as the repair would have been.
Based on my experience, I can highly recommend him for those of you who have some old equipment that you may not be ready to replace just yet, and need repair assistance. He spent a good deal of time with me on the phone and via email, and helped me get what I needed for a very fair price. He also moved me up in line so I would have a unit back in my hands, in time to travel back to the boat this weekend.
I hope someone will find this information useful and thank you in advance for any responses regarding the Onan Zinc.
All the best,
SM #466 - s/v Rita Kathryn