Galvanic Isolaters & RPM's

lobsta1 · Post by **lobsta1** » Wed Nov 05, 2003 5:58 pm

I keep my Mistress in a "hot" marina. That is, everyone complains about zincs getting eaten up. In 2002, pulled out in June to do bottom work & put 9" x 30" tabs on. Also remounted the original swim platform. Had to haul for the winter middle of Oct. to rebed the rudders.(Bilge pump was coming on every 17 minutes) A little piece of ONE of the four total shaft zincs was left. Of the tab & rudder zincs, only the screws were left going through the holes. That's in just over 4 months. This season I launched on May 9. I'm staying in for the winter. Last Saturday, pulled into a shallow area, & had a friend dive down & replace my zincs. They were only half gone. Guess what made the difference? Middle of June I put a 50 Amp Galvanic Isolater on my combined two 30 Amp power inlets. I purchased one of the refurbed units from Yandina.com. Everyone else is STILL complaining about zincs. At launch I was turning just over 3900 RPM on rebuilt 1978 BB Mercs with no canvas up. This summer the port engine developed a carb whistle & was way down on power. Could only get 3200 port & 3400 stb. Was out of commision a long while from rotater cuff surgery & could only get to it a while ago. Me very BAD. Had not replaced fuel filters & when I pulled them, found them full of gunk. Assumed something got into the port carb. Finally got the Carter AFB carb off & tore it down. It was so dirty, I'm amazed the engine ran at all. Cleaned it all up & put it back on. Still running very rich & only picked up 100 RPM. Took it apart again & found 1 small passage still varnished up. Back together, but no change. Started pulling plugs & found that one of the plug wires inside the boot had come off the plug. Hence, I was only running on 7 cylinders. Saturday, with full fuel, water, four people & dive gear with canvas up, was able to turn just over 3600 on both engines. Merc valve cover says WOT is 3800. Bertram manual says 4000 RPM. At fresh launch, I was happy with 3900. Moral = Check the basics!!!!!!!!!!!!!! I'm strictly a Unifinger typist, so I quit now. Al 1978 33 FBC NITES OFF

Post by **dougl33** » Thu Nov 06, 2003 3:11 am

Al, Good job. I knew you'd find the problem. I'm sure your boat has got a fair amount of growth on the bottom since you sat for so long. Once you clean the bottom in the spring I'm sure you'll pick up those few lost rpms. When I left your marina a couple of weeks ago, I was able to get a little over 4100rpms with 2/3 fuel, full water. and 2 pob, good for just over 28 knots. Thats pretty close to what I'm looking for so I may be done screwing around with my props. Do you have electronic ingnitions on your engines? FYI: I hauled out last Sat. I will be winterizing and shrink wrapping tomorrow (Fri). Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth

will newton · Post by **will newton** » Thu Nov 06, 2003 5:06 am

Al and others, I go through some zincs at a rapid rate as well and I'm not in a real "hot" marina (though I would suspect they have some electrical issues). Just replaced an original (1989) "thin" trim tab as it was half eaten away. Noticed you are rebeding rudder shafts. I too have a very active bilge and most of the water is comming from my port rudder shaft (same side as bad trim tab). I have had the post rebeded but still leaks pretty good after a month or two. Did you discover any pitting on your rudder shaft? Did your rebed solve the problem? Do they make dripless rudder logs? Also, someone told me that if you run your a/c continuiously on a Bertram (I do here in Jax Fl to keep mildew at bay) you will eat through zincs faster as the boats are notoriously bad with electrolisis. Any conection with the rudder posts? What do you think? P.S. Your pretty good with one finger...must be the recent excersises from all that Carb work. Will Newton 1989 FBC

lobsta1 · Post by **lobsta1** » Thu Nov 06, 2003 10:02 am

Will, it was my port rudder leaking also. It was NOT the packing. Water was coming up from around the base. When Bert built our boats, they bedding the entire rudder port in a polyester putty, between the bottom of the hull & the rudder port flange. When I pulled the entire assembly out, that bedding was in pieces. Prior owner had just gooped some LifeCaulk around the tube from inside the boat. Coming from Maine 2 seasons ago, we hit some seriously rough water. After that is when I started leaking.Posted on the B31 board about what to do. Was told boat had to come out & everything pulled out. Then clean up everything. (Bearings on shaft are held in with TWO allan set screws. About 90 dg apart). I cut my bearings off with a 4 1/2" grinder with a cutting wheel. When you are all ready, (with 2 guys) mix up a batch of thickened epoxy, butter up the flange & slide the port back up. The inside guy has to make sure it is lined up & tighten down the bronze nuts while keeping the alignment & correct height as you squeeze the excess goop out. There is a mahogany plank glassed into the hull. That will be saturated with water. I left mine exposed all winter after trying to dry it with acetone & a heat gun. Water just kept wicking back. No rot though. Also, if you have to go this route, coat the rudder port with mold release before the epoxy. If you have to do this & have any further ???'s, just post back. Al 1978 33 FBC NITES OFF

will newton · Post by **will newton** » Fri Nov 07, 2003 8:38 am

Thanks Al. Not sure I want to tackle that job. I hit the packing with a 1/2 turn of the wrench every other month and it seems to slow it down a bit. Sounds like a good solution and I'll look at it when i pull her in the spring. Best Will Newton

captgene · Post by **captgene** » Mon Nov 10, 2003 5:22 am

Hi Guys, I have a Galvanic Iso on my 33. It was put in at the factory. Only once did I have a electrolysis problem. A Carver across the canal from me was cooking. I was going thru zincs every 6 months. The guy sold the boat, and now it's been 1yr this month, and my zincs are hardly eaten at all. I check all the ground wires on through hulls every month or so. Make sure nothing is loose of corroded. Haven't had any rudder problems, and my boat is in year around. I did find some really expensive packing on the web. I did all the packings last year, and nothing drips. It really works. It's called "GFO" Fiber Packing. e-Marine web site. A lot cheaper and safer than the dripless. E.W. Dugan