Rudder Attachment to 26M Hull

[Wandering]

When I had my boat on the hard for bottom painting, I noticed something of grave concern.

The attachment or stainless steel plate that affixes to the hull for the rudders has four bolts in each plate for each rudder. During the winter I noted a pesky leak that I traced back to the rudder connection on one of the four bolts on the port side. I applied some adhesive and it was fine for the rest of the winter.

In Spring when I pulled the boat out onto the hard, the heads of the two of the bolts on the plates were gone. If it weren't for the sealant (3m 4200 I would guess) on the washer and the nut of the bolt on the inside, I could very well have sunk or filled up with water. I never considered a bilge pump before since we have no real holes in the hull to worry about.

I replaced all eight bolts (four on each plate). On examination on two of the other bolts, I noted that the plate had rubbed nearly 1/2 of the width out of one of the other bolts.

So what may have caused this? I can't see anything on the forum regarding this but the rudders are to say the least problematic on the 26M. I did have last season two challenging sails across the Georgia Strait here in Vancouver, reefed main, following sea which forced me to track off course to keep the boat from surfing. Occasionally though I did have to think fast to prevent broaching putting pressure on me and the steering. Or possibly the bolts had loosened adding downward pressure on the bolts from the plate, like a guillotine.

My boat is in the water year round. I was surprised to see that on the 26X the fittings for the rudder are our of the water. I have had some rusting on bolts. So I have added anodes that clip onto the rudder fittings to electrical wire connected to a anode that is in the water. I hope this keeps the rusting at bay.

I think I have it under control I hope. But the important thing is to let other folks know about this and to check their fittings on the 26M (mine is 2007). I always find that a good polish and wax over the entire boat can uncover some "spring" jobs!

[wardski]

I too have this problem. My boat is a 2004 and I have been watching the heads of the bolts that hold the rudder brackets slowly erode. They are to the point now that they still hold the rudder bracket on firmly but there is no way a socket wretch can be used to turn them so they can be replaced. Not sure what is causing this but eventually this is going to be quite a repair job. For now though, just sailing and having fun. When the rudders fall off, I will fix. But have two rudders with four bolts each so don't anticipate it will all go at once.

[Wandering]

Possibly you could use a vise grip on the outside (have someone clamp it and hold it) and then see if you can loosen the nut on the inside, then knock the bolt out from the inside.

Alternatively replace the ones you can, assuming not all of them have the problem of not being able to be wrenched. Or you may be able to use a tap set for the troublesome bolts, but as I know from the other pesky issue with my 26m (which I will describe below) tapping stainless steel is time consuming task.

The other issue I have, is the stainless steel screws that hold the plastic strip that covers the sides of the companionway. Very small phillips head screws that are not easy to find (in Canada at least) hold this in place. I noticed the head of one or two missing and each time some one went in and out and naturally stood on it, then it started to lift and move. To see if I could get them out, I had to unscrew the others t remove this plastic strip. Well, as i screwed them off, off came their heads, leaving me with a total of about a further 1/2 dozen screws with no head in the fiberglass. So I managed to get one out with pliers, but the rest have proved very tricky. I tried to tap them with a product that is designed for this purpose, even with magnifying glasses, I still managed to go into the fiberglass, of the one where i made some progress, the drill bit set that I was using (designed for this) found it hard going, nearly an hour on one screw, and not deep enough. Literally I am a bit screwed!

My options are to drill around the screw carefully, and then see if i can get pliers to it,or keep going deeper. Then epoxy the hole. Or, take the whole thing off and see if can get a plastic strip that can be fixed by adhesive.

[Ixneigh]

Cheap stainless. No excuses. Hope Tattoo takes note. Mine are rusting. I replaced a few already. I will check and replace those rudder bolts this season.
Ix

[raycarlson]

Any fasteners you see suffering from Macgregoritis (profit in lieu of quality) should be replaced immediately while there still removeable and replaced with quality 316 grade stainless material not the cheapo 304 stuff Macgregor uses in the factory.

[Wayne nicol]

its such a sad SAD story, i love my , and everything it represents- and i do know this has been debated ad nauseum on here- and i dont want to open that can of worms again, but my main gripe is even though the fasteners are poor quality( incedentally also a huge issue) ,and lots of other construction corners cut etc etc,
but heck it costs the same to bolt something on crooked or straight- so many things are crooked and badly attached,- screws all crooked and not square to the surface- just looks chintzy-
But also inconsistant fiberglass thickness on the deck- some parts crack when i walk on them ( i ony weigh180 lbs)- same part, opposite side of the boat doesnt crack and flex- just feels cheap- some of the fixtures inside flex and crack when you put some pressure on them too...
i like i the boat in essence and i will use it till it falls apart, but i am gonna build my own hi speed motorsailer- so then i know its done right.--- no complaints just observations!!

[Wayne nicol]

apologies for hi jacking the thread!!- just rolling on with what ray said- i agree with himX10
back to being positive now- had my gripe

[Crikey]

We've been to these places and not had to endure prolonged salt water immersion sufficient to exhibit any bolt head degradation yet. Aside from corrosion I think part of the problem has to do with insufficient factory tightening and an inadequate supply of 5200 type sealant.
I didn't know our stainless was 304 grade. I wonder what Home Dep is dealing these days?

[seahouse]

Hey Ross!

304 is the most common grade you will encounter, so economy of scale has made it the cheapest available – most hardware store screws will be 304 (especially if they don't specify it on the package). It is also the stronger and more wear resistant (than the other common grade, 316); so, in spite of listening to the perpetual bellyaching about it here , it would be the logical choice for a competent boat designer to specify for applications we see on our boats, regardless of the economics.

In addition to 304, specialty marine stores will also carry 316 grade fasteners which cost more (less economy of scale) but are more resistant to pitting and crevise corrosion, but are weaker, and will wear faster at bearing points like are present on our boats, and more specifically like the bearing point shown in your picture above.

Just checked my bolts from the outside – they look like new after 3 season's continual immersion in fresh water. They look to be 1/4” bolts, so being of soft stainless they can easily be removed by simply twisting them off with any wrench or socket, if they are corroded and seized and need to be removed. Those screws, being of soft stainless steel, even without having been corroded, will shear off like butter with hand torque.

If I were concerned about it (and I certainly am not, being in fresh water) I would simply remove them and drill out the holes to take 5/16” (or 3/8” ?) bolts. In some cases, simply substituting the weaker 316 grade part for the 305 grade part would be imprudent if its strength were critical. It would be weaker fastener right off the bat, but might be the stronger of the two alloys after say 10 years' salt water corrosion, true.

- Brian.

[seahouse]

The boats are well-designed, but suffer from poor workmanship on assembly, true. Same thing happens in Detroit, doesn't it? On the other hand, it can be tough to get good skilled employees, and I'm not aware of those specific issues in California.

Fifty different times while working on my Mac I've thought to myself that I could have the majority of the issues solved after spending two weeks in that plant. At no extra cost in time of production, but just a few tweeks in tooling and proceedures. I think that's exactly what you are saying, Wayne, and it's referred to as “quality is free”. I have a book by that name on the topic.

I also think, if it is the case that the price has been kept low by the absence of skills-appropriate training, that a lot of Mac owners would not be able to afford a boat of this size. Meaning, they are price-sensitive, and would not have bought if the price were, say, $5000 higher. That would have impaired the business success through reduced sales volume.

The stark reality that always remains is that nothing else on the market at any price, or quality level*, can do what a Mac can do.

* and, BTW, have you checked the quality of workmanship and reliability of other boatmakers on the market? Macs are not so far behind some others in that department. (I know of a steering loss on the maiden voyage of a 34' keelboat, hours after delivery). You don't hear about them because the owners are too embarrassed. That factor skewed auto quality reports for luxury automobiles in the early days of quality reporting.

[raycarlson]

Well you are correct on that point. I purchased my 26M fully aware of the quality and materials used to keep the price affordable knowing I have the skills to totally rebuild and modify it. I pity the poor soul who thought they were getting Oyster quality and posess no mechanical skills or tools and has to pay a shop to work on his boat. As far has you comment on stainless alloys your a little confused as most all stainless alloys are much harder and much more brittle then any grade 5-8 steel fastener, the loss in shear or tension between 304 or 316 is not even worth debating unless possibly its on the space station where they exactly match load with fastener size for weight considerations. On our little boats any fastener used is way over sized to worry about a loading failure. Now the strength difference between stainless and carbon steel alloys is a much wider margin and might require some consideration, regardless stainless is in no way "soft".

[Ixneigh]

Roger that use it till it falls apart!
Re decks, same thing was happening to my boat, so I fixed it. Roger stated it was not affecting the safety of the boat. It was affecting my sanity however.
Ix

[Wayne nicol]

i hear you ixneigh,
i just cant stand the crackling and flexing of the deck and the bunks below.
as i said i love the mac and all it represents, and i will use it till it eventually dies- but in the interim i have already upped the ante'
i have started the design process with a highly respected boat designer, who has done lots of work with regards to fuel savings/hydrodynamics, and they have already designed and built a few high speed motorsailer type boats of different sizes and configurations. pretty advanced and experienced design studio!!!
i am considering a trailerable 32' by 10' with a more traditional top sides- but pretty advanced below the waterline, it will still do 20kn with twin 70's- i like the redundancy of twin motors up here on our coast.
proper head and shower- two "cabins", better galley and full length wet locker for all our wet gear up here , huge cockpit , inboard fuel ( i like the idea of the diesel outboards!!!)etc etc
its gonna be a long process- and in the meantime i will keep loving on the

[seahouse]

As far has you comment on stainless alloys your a little confused as most all stainless alloys are much harder and much more brittle then any grade 5-8 steel fastener, the loss in shear or tension between 304 or 316 is not even worth debating unless possibly its on the space station where they exactly match load with fastener size for weight considerations. On our little boats any fastener used is way over sized to worry about a loading failure. Now the strength difference between stainless and carbon steel alloys is a much wider margin and might require some consideration, regardless stainless is in no way "soft".

Ray - maybe I can clear up some of that confusion, wherever it might be located ...

The misconception that stainless steel screws are somehow stronger or harder than standard (grade 5 to 8 as you defined) steel screws is a commonly held one, outside of industry. I'm not sure exactly why that is (maybe “shinier is better”?), but the erroneous perception gets perpetuated on web forums, I would guess.

While considering that the large number of different alloys and heat treatments for both stainless and non-stainless steel screws might complicate the issue, the basic premise, and especially as it applies to the specifics of this thread topic, remains.

My reference books are at work, but quick internet boo gives tensile strength (yield and other metrics will be similar) for 1/4” course stainless steel bolts at 2550 psi , and 1/4” coarse grade 8 at 4770 psi! But choose any actual sets of numbers, and the conclusion will remain the same.

So looking at the full spectrum of the hardness of ferrous fasteners, the stainless alloys under discussion land clearly in the realm of being described as “soft”.

Hope this info is helpful – Brian.

[seahouse]

Wandering --

Sounds like water intrusion through the holes softened the thickness of the hull through which the bolts passed. This reduces the clamping force that is needed to securely hold the rudder mounting bracket in place.

If you happened to apply the sealant from the inside of the hull (which is a no no on a boat, BTW) this would have stopped the water from entering the boat itself, but not from entering the transom wall, which would have allowed water ingress to continue.

The now-loose mounting plate will move with every turn of the rudder, or wave, and will eventually saw through the bolt heads, (even if they are 304 instead of 316).

It's something to check – good luck.

-B.