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A few questions...
Posted: Wed Jun 04, 2014 5:02 am
by Robby57
So I got my first boat a few weeks ago. An 82mac 25. There are a few things I haven't been able to figure out. How did the shore power hook up originally work on these? It appears to me like it just kind if acts as a through hull running basically to an extension cord In the cabin. Is that fairly accurate or was their originally an inverter or battery charger setup in there? On the rudder mine is bolted in such a way that it does not swing up. Does anyone have close pics of the bolt setup and im guessing some sort of rope too since there is that little pully on the side of the rudder mount? Can anyone explain how that is intended to work? Lastly, at least that i can think of right meow, two of my styrofoam blocks were in the cabin. Do they go behind the rear bulkhead or i guess where all are there supposed to be blocks at in the boat? Thanks in advance for any help.
Re: A few questions...
Posted: Wed Jun 04, 2014 6:24 am
by SENCMac26x
That's pretty much how mine was setup, an adapter to a cord to a power strip in the cabin. I did have a batter charger plugged into the strip.
Re: A few questions...
Posted: Wed Jun 04, 2014 7:13 am
by Tomfoolery
Shore power wasn't original equipment on any Mac, AFAIK. An owner did that. Be advised that shore power is 120V, 30A, and without proper overcurrent protection, you'll be powering a cheap power strip with potentially more than twice what it's rated for. Watch your loads.
Or put in a real shore power panel.

Re: A few questions...
Posted: Wed Jun 04, 2014 7:17 am
by Robby57
Thanks that's about what I thought withe shore power deal. I thought of one more on the Bimini top is there supposed to be some device to lock it in position? Mine will raise up and rock all the way back until the support rests against the hatch.
Re: A few questions...
Posted: Wed Jun 04, 2014 9:01 am
by Robby57
So I found the rudder thread. So that's out of the way.
Re: A few questions...
Posted: Wed Jun 04, 2014 2:47 pm
by Steve K
Here are some pics of my 26D rudder setup. Yours should be something similar.
https://app.box.com/s/fd1042cab40bb3e44c61
Best Breezes,
Steve K.
Re: A few questions...
Posted: Wed Jun 04, 2014 3:32 pm
by NavySailor
Hi Robby - I just bought a 1986 25 a few weeks ago. Here's what my rudder set-up looks like. I haven't used it yet, so not sure if it's right or not. Missing a pin or something to hold her down once I am in the water.
Let me know if you need some different angles or a close up of something.
(yes I need to paint the rudder too....)

Re: A few questions...
Posted: Wed Jun 04, 2014 6:45 pm
by Robby57
Thanks Steve k those pics clarify a lot! It looks like I may be missing that whole plate that's bolted to the front of the rudder mount. I keep putting off actually setting up her mast and rigging because im afraid of what may be missing. Im sure I will be back as here as this project scoots along. Theres a lot of good info in here Just lurking but a lot that I simply have no idea about because ive never owned any boat before. I think I will start a build thread though as shes getting a ton of work done to her.
I thought of yet another question I have not been able to get a real clear answer about by searching.
I will be taking this boat to salt water though shes been fresh all her life and it may sit in the water for extended periods. I plan to sandblast ,fair, barrier coat, and bottom paint the keel but should I also install zincs? If so how would one go about that? Is it a matter of bolting one on and then connecting a wire from somewhere on the keel to battery ground?
What do I need to do to the Johnson 6hp seahorse to get her ready for saltwater?
Re: A few questions...
Posted: Thu Jun 05, 2014 6:03 pm
by Steve K
Robby
The plate on the back of the rudder head has been added. This prevents flexing.
The up-haul system that is mounted on this plate in my pictures was originally on the port side of the rudder head. The down-haul is in the original place, on the starboard side of the rudder head.
Not sure about the zinc question. All I know is one should be mounted low on the outboard. The one iron keel I did have, I sand blasted and encased it in epoxy fiberglass, so no corrosion issues.
I do know this, for sure though........... You should not sand blast Gelcoat. This produces micro cracks in the gelcoat which increases the probability of blistering. Perhaps Soda blasting or Walnut shell would be okay, not sure.
I've stripped four hulls and have always used stripper (must be for fiberglass specifically, regular stripper will destroy the Gelcoat), followed by orbital disk sanding (#80 to # 220, depending on the condition of the Gelcoat).
Best Breezes,
Steve K.
Re: A few questions...
Posted: Thu Jun 05, 2014 7:57 pm
by Ixneigh
I had a chunk of lead in the tip of the rudder on my v22.2 which kept it down nicely in most conditions. I may eventually do the same thing on the rudders of the M.
Ix
Re: A few questions...
Posted: Thu Jun 05, 2014 8:40 pm
by seahouse
Hey Robbie – congrats.
1

Wherever you buy your blasting media will be able to help you choose which media to use on a fibreglass boat. But as Steve says, it's not sand or glass.
2

However you secure your rudders down, it would be best to allow some way for them to give and rise without major damage (eg a shear pin) in the event you hit a solid obstruction.
3

If the boat was in fresh water and has sacrificial anodes they will be (or should be) of magnesium. If you are now going to put the boat in salt water you want to substitute them (it) for one(s) made of zinc, which is a less noble (electrically reactive on the periodic table...high-school chemistry) metal than magnesium. The magnesium will still do the job, but will be consumed far too quickly.
There should (but might not be) an anode (chunk of metal or plate) bolted somewhere on the body or bracket of the motor, or both, you will have to look for it if you don't have the manual for the motor. It could also be part of the trim tab or skeg, but will be unpainted, and corroded or pitted, at least a bit.
They work by sacrificially corroding in place the metal they're connected to to protect, so need to be replaced periodically as they disappear. Their connection to that metal has to be electrically continuous, so the contact area needs to be cleaned when they are replaced.
Note that this is only to protect metal that is in (continuous) contact with the water. If the motor is kept tipped completely out of the water when not in use there will be less corrosion to it and the prop. But if the mounting bracket is still in contact with the water, there needs to be an anode connected to it for it to be protected.
4

A simple shore power system, wired correctly does not need any connection between the battery and the water outside the hull for grounding or anodic/ cathodic protection.
Be sure of what you are doing - improperly connected shore power can greatly accelerate the rate of corrosion on any metal in your boat and other boats nearby. As well, it can, and has been, fatal to swimmers – which is one reason swimming is verboten in marinas.
This is a brief summary – ask if you need more details. Good luck!
-Brian.

shore power
Posted: Tue Jun 10, 2014 5:58 pm
by Madelon