Mac 25 cast iron keel CHECK YOUR KEEL!

Feb 10, 2014
10
macgregor 25 Vancouver
I just bought 1984 Macgregor 25 and as expected it needs keel work. With the boat on the trailer I drew a line on the keel along the hull, I then used a jack to raise the keel under the pivot point just enough to pick up the slack, then drew another line along the hull. The space between the lines measured 7/8"!!!!! After removing the keel from the boat I discovered that there was less than 1/2" of cast iron left holding the keel. (this would be when the keel is in the Horizontal position) This would fail if the keel were down and the boat grounded or it could fail while on the trailer, either senario would be bad. So all fellow Mac 25 owners do this simple test it only takes a few minutes.
Fair Winds, Brian Stoner
 

ejet99

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Apr 30, 2010
46
Venture 224 Belfast ME.
Are you saying the pivot hole is worn or elongated? Can't check mine it is up at camp.
 
Feb 10, 2014
10
macgregor 25 Vancouver
Check your hell

Are you saying the pivot hole is worn or elongated? Can't check mine it is up at camp.
Yes the hole was elongated and also rusted from the trailing edge the material left was about as big as my pinky finger! Bolt had slight bend and no wear on bolt hole on boat.
 
Feb 10, 2014
10
macgregor 25 Vancouver
I will post a photo soon, the bolt was only slightly bent there is only a rusty piece of iron the size off my pinky left holding the keel!
 

ejet99

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Apr 30, 2010
46
Venture 224 Belfast ME.
New Hole

I am getting ready to re-seal my cast iron keel and we were thinking if it was possible to drill out the hole and fit a bronze bushing. It would have to be done very carefully to keep from cracking the cast iron. My pivot hole turned out to be O.K. but I think it could be done.
 

Kestle

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Jun 12, 2011
702
MacGregor 25 San Pedro
A bushing needs to be welded, and you need to find someone with experience welding cast iron.

Jeff
 
Feb 10, 2014
10
macgregor 25 Vancouver
I don't think the bend will make a difference the slack is due to wear on the hole or bolt so if it has more than 5/8" slack the keel hole should be looked at, my slack was 7/8 plus corrosion coming in from the trailing edge made for less than 1/2 inch of keel material left.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Posting pics for modslot;


:eek:


I'm going to also post these in my photobucket acct since we know SBO looses the pics once the thread goes to archives.


thats the worse I've seen...
so what do we know about this boats previous life?
moored in warm salt water?
 

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Fred

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Sep 27, 2008
493
Catalina 28 mkii 745 Ottawa, Ontario, CA
Based on Modslot's location I am guessing this boat was sailed in salt water. Has anyone ever had significant keel corrosion problems on a boat sailed in fresh water and hauled out for winters (i.e. 6/12 months a year)?
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
IIRC, someone welded up thick plates of steel

- not sure how long ago or the thread title...
 
Aug 12, 2012
12
Catalina 30 MKII Pensacola
Freshwater

Based on Modslot's location I am guessing this boat was sailed in salt water. Has anyone ever had significant keel corrosion problems on a boat sailed in fresh water and hauled out for winters (i.e. 6/12 months a year)?
I owned a Mac22, built in 1983. When I had it, it was already 20 years old. It showed minor surface corrosion and no significant issues with either the pivot bolt hole or the cable attachment point.

I sanded it and put on an epoxy coating (multiple layers).

FWIW.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
I just noticed the locking bolt hole is not too bad....

I wonder if locking the keel would have avoided some of this 'wear'

(or the PO never locked the keel so it was being eaten away from use, vs corrosion ) ??
 

Fred

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Sep 27, 2008
493
Catalina 28 mkii 745 Ottawa, Ontario, CA
"I wonder if locking the keel would have avoided some of this 'wear'"

Is it possible that there is some type of galvanic corrosion going on? My Mac had a grounding strap attached to the pivot bolt which could provide a current path through the bolt and keel?
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
the problem like the one described is almost always caused by the owner of the boat .

the most wide spread problem for the keels on these swing keel boats is caused when the boat is moored for a long period of time and the owner cranks the keel up as its moored....
this allows the keel to rock on its pivot bolt and the hole to wear in the direction of "escape", or towards the edge. AND, the keel WILL rock more and farther side to side when its cranked up than it will when its down, locked or not... the keel is designed to be stable when its down with the lock bolt in place with the tension removed from the cable. it IS NOT designed to be stable at at other position or configuration.

also, if the lock bolt IS in place, you have collectively more surfaces to wear, so it will take even longer to wear a noticeable amount.

its perfectly fine to moor the boat with the keel in the down position, as it has a lot of wearing to do in this position before there is any chance of the hole wearing thru....AND it will take longer to to wear any given amount, as the motion is reduced considerably.
It should never be moored for any length of time with the keel up, as can be seen by the wear, and the direction of wear, on the pivot hole.

with normal usage and overnighters, weekends and such, with the keel up will NEVER be a problem for many, many years with never a thing to worry or wonder about, but the long term moorage with a retracted keel will eventually become someones problem

when the hole wears directly toward the edge of the keel, its not because the boat has seen a lot of use, but because it was moored with the keel up.
salt water will allow it to wear more quickly as there is a higher corrosion factor, but even if the keel were in the down position without the lock bolt in place the hole could wear a couple of inches without worry of escape.... with the lock bolt in place it will add extra support and keep it from EVER becoming a problem in our lifetime....
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
^that makes a lot of sense.

what does a M25 draw? 5'-6'?

on the west coast shouldn't be a big issue.

on the east coast, often smaller boats are moored in less than 6' (and you need to allow for wakes/storms)

in So Fla, its pretty hard to find 8' depth in a mooring field.
-docks are better since they dredge the harbor for them.
 
Jan 10, 2011
319
Macgregor 25 675 Lake Lanier
My keel was in fresh water as far as I know.

I always keep my keel up and rudder up when in a slip. If the keel starts hitting the bottom I think it will cause more damage. I use a slip in Florida that is shallow and on Lake Lanier you never know when the level will go down enough to have the keel hit bottom. When it is on the lake and I am not sure when I will be back I pull up the keel. I have a slip near the shore. I think I may switch to a slip further out and lock the keel down.

I added some pictures of my keel pivot hole. The bolt looked brand new when I checked it so I am still using it.
 

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Feb 10, 2014
10
macgregor 25 Vancouver
Good info on extra wear caused but the keel in up position, I believe both owners one in Vancouver and prior to that California I found mooring receipts for both places and in the salt. The lock bolt was seal off with silicone so never used