Rudder replacement

Sep 3, 2012
195
Hunter 285 Grand Rivers Ky
About to replace the aging and rattling rudder on my Mac 22. So, I looked around and rudder craft sells two different types of naca rudder. They are both said to be for my Mac, a high performance fiberglass and a solid HDPE.

Is one better that the other? It one more durable in the face of abuse than the other?
 

Sumner

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Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
About to replace the aging and rattling rudder on my Mac 22. So, I looked around and rudder craft sells two different types of naca rudder. They are both said to be for my Mac, a high performance fiberglass and a solid HDPE.

Is one better that the other? It one more durable in the face of abuse than the other?


Our boat came with the HDPE one and have been happy with it. Chewed some holes in it with the prop by accident :redface: and being solid not a big deal. Not sure what would happen with the fiberglass one they have (is it hollow...probably). If you know you are going to keep the prop out of it then for sure that isn't going to enter in the decision. I'm wonder how to repair mine or just leave it alone. Glass would be easier to repair if damaged.

There were some reports of the HDPE ones breaking but I think they found out the cause and that isn't in the picture anymore.

If you decide on the glass you should report back as that might be an interesting review especially for the racers on here,

Sumner

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Erik V

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Mar 14, 2012
104
Macgregor 25 Stony Point NY
Purchased their fiberglass model for my M25 and have used it for 2 seasons with no issues. Mine was shipped blank so the pivot hole and lift hole needed to be drilled and bushed and sealed. Its far superior to the original. I dry sail so its not in the water for extended periods.
 
Nov 23, 2011
2,023
MacGregor 26D London Ontario Canada
I've taken a look at the HDPE type and am concerned with the fine cracks I could see in it. When the rudder was down I could see fine lines running horizontally through the top 1/4 of the rudder. They looked to be about .5 - 1mm deep. I don't know how this particular rudder was treated or if it spent all it's time in the sun or not. Or if it was hit in any way from the side.
I personally would go with the fiberglass one. At least you will know it will last about as long as the boat. Unless you put the prop into it...
(I made prop guards out of HDPE and pop riveted them to the rudder side of each motor. Cost $ 4.)
 

Attachments

Jul 1, 2012
306
MacGregor 26D Kirkland, WA
Our boat came with the HDPE one and have been happy with it. Chewed some holes in it with the prop by accident :redface: and being solid not a big deal.
I did the same thing - twice - in that first season with her. And once at the ramp, forgot to untie the rope that tensions it in the down position... figured it out as my buddy was hauling her out of the water. So - a couple prop cuts and some scratches on the bottom and the rudder is no worse for the wear. I've heard that the foil shape on the HDPE rudder give more steering power. I cant say to that as I've never used the factory rudder.
 
Sep 3, 2012
195
Hunter 285 Grand Rivers Ky
Well, went ahead and ordered the solid HDPE rudder. My old Fiberglas rudder gurgled and had a wooden stiffener down the middle that was compromised. However, it was explained to me that the wood was only required till the fiberglass cured when it was first made, that after that the fiberglass was plenty strong enough. Never could get all the water out when on land and the freezing temps did not help in the winter months. Took forever to get the air out in the water so it could be tied in the down position. Suppose I could still run it but it wobbles when at anchor and the bump, bump, bump keeps me awake.. Was told to install bushings to stop that. But, in the end the appeal of a new, solid rudder that water can't get in and a lifetime warranty won out. Will report when next in the water on how it works.
 
Apr 24, 2006
868
Aloha 32 Toronto, Lake Ontario
I have broken and Ruddercraft HDPE rudder....

It was an early model where the cheek blocks were "plastic welded" all around. The bottom weld weakened the rudder and it failed.

Ruddercraft has since updated their design and does not weld this area anymore.

They also replaced my rudder no questions asked. The only issue was shipping and a border crossing - all tat cost nearly as much as the rudder itself!

Performance? My old rudder was exactly the same airfoil and shape (except bottom was rounded vs square). I saw no difference in performance but there are many that say they do. My old rudder was a factory rudder although many claim the factory one has "no airfoil" shape to it. I have not seen one of these "shapeless slab" rudders on any 26S or D that I have looked at...

Now one thing that WILL kill your new rudder is not making sure it stays absolutely down. A couple inches kicked back at hull speed and the tiller pressure will be extreme - and you WILL eventually snap the rudder. Many think this is "weather helm" - but it's not.

Stress cracks wouldn't worry me due to the excellent warranty. HDPE is over 90% oil (barely a solid). UV causes the oil to migrate inwards with subsequent weakening and surfacing cracking. But unlike a conventional rudder, the HDPE does not get most of it's strength from the skin. Bottom line is that a few surface cracks have no effect on strength.

Chris
 
Aug 14, 2012
40
Macgregor 26D Mosquito Lake, Cortland Ohio
I made a replacement out of wood. White Oak . Copied the air foil from the old one, put a couple coats of epoxy on it, and it works fine. Total cost $75.00.
I don't do any racing, or sail across the ocean, so it works for me.
 
Nov 23, 2011
2,023
MacGregor 26D London Ontario Canada
I've made a couple out of pine wrapped with a fiberglass and Kevlar weave. I did a vacuum bag application on the one. The other is yet to be covered. I think I will do it with a roller. I think it's quicker that way. Less prep.
 

sunman

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Jul 29, 2009
112
Mac Mac 26D Suwannee
made mine outta 2 pcs of marine 3/4ply and gave it 12% foil, wraped in glass, it's sooo smooth in the water U cant even feel it on the tiller , I say that because I did the rudder mod to the org. 26 rudder and it had a lill vibration in the tiller, I think it's because I didnt have a great airfoil shape, it's my spare now, ya never know!
 
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
I have a huge vibration in some conditions but my rudder is in pretty bad shape. I started to make a new one by ripping a 2x12 into 2 1/2" pieces and flipping the grain, and gluing and clamping them. I drew the shape on the ends and tried to cut the pieces down before gluing them but without a belt sander, I was unable to finish.

I like the 2 pieces of plywood approach. That may be better but again, without a way to get rid of material via sanding to shape it will be too hard. Someone here used a planer with a fixture to take some meat off. I don't have one of those either. At some point I will justify the belt sander when comparing the price of a new rudder but for now I just have to live with what I have.

I don't have any buddies that are good with wood. I mean I built my own kitchen including all the cabinets, doors and even door pulls but just don't have the belt sander. The air foil part is what I am having difficulty with
 
Sep 3, 2012
195
Hunter 285 Grand Rivers Ky
Seems to me that if you have vibration on you rudder you may also want to check your castle that holds the rudder. If it is an aluminum castle
 
Sep 3, 2012
195
Hunter 285 Grand Rivers Ky
Oops, trying to correct auto spell and accidentally sent it too soon.

Seems to me that if you have vibration on your rudder you may also want to check your castle that holds the rudder. If it is an aluminum castle it can both bend and or twist ever so slightly. This may also set up the rudder to wobble in the wake of the keel. But I dunno...
 
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
Well there is a split on one side where it was at one point repaired down to the wood and then a terrible glass job. It's just not smooth or does not have the proper foil shape.

I have the S model so my "castle" is internal.

One thing I noticed is that my rudder actually goes beyond vertical when hauled down all the way. I will try to address this if I ever get around to trying again
 
Nov 23, 2011
2,023
MacGregor 26D London Ontario Canada
Doc. You need a belt sander.
I made my rudders with a belt sander. Started with 36 grit, then 50 and finished with 80.
I used a drawn on template on each end of the board to get the foil shape. (0012 ish)
I clamped the chunk O wood to a table and worked the whole piece from end to end.
You can tell if your getting off track by the feel of the belt sander as you work form side to side.
You'll figure it out.
Part of your vibrating problem I'm sure is caused by the rudder being over extended forward. Ie: \
Check the old thread I started last year about repairing the Mac for charter. It has my rudder build in it. (Look under threads started by me.)
 
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
You are right. I may have to build a stop so when I hail it down it doesn't go past vertical at least as long as I am using my current rudder. Hopefully I will just get off the pot and buy a belt sander.

I had played with fiberglass years ago but have not in probably 30 years so I am sort of looking forward to trying that as well.
 

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
my rudder also goes slightly past vertical - i.e., a little forward rake. I think its OK.. a lot of forward rake can be worse for stress than the rudder raked back too far but just a little forward rake I think actually puts the rudder center of effort more in line with the rotation axis.. which I think.. is a good thing.

I get some vibration on the centerboard but I dont think I ever get it on the rudder (its a rudder craft plastic one likely perfect foil shape since I think these are likely cnc milled)
 
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
The hole placement is further back than I thought and leaves some rudder forward. Not like the ruddercraft ones with the extended leading edge. That along with the past vertical is probably plenty.

I can tell you this, if it is even slightly back (not completely hauled down) you can feel it in the tiller. It doesn't take much to make it hard to turn. If it's back a few inches one would almost feel like the tiller will snap.

For this reason, I question the macs ability to cross 2 feet of water. Sure you can pull the keel up but it's not easy to deal with on the rudder end. I suppose motoring is an option there.

FWIW, I always lift my rudder out of the water completely when it's in the slip to keep the growth down. I also tilt my motor out.
 

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
I used to keep the boat on this shallow mooring - its probably 3 to 4 foot under the boat in the picture and sometimes I would have to come in from the shore direction so it was even shallower. I would always put the centerboard most the way up, put the rudder also most of the way up and motor in and pick up the mooring. You cant put much pressure at all on the rudder but if you can vector the outboard, you also dont need much.

The shallow mooring sort of sucked.. but on the other hand.. it was the ONLY one available and I could still fairly easy use it with the Mac..

When the rudder is up about 45 degrees, my prop can meet the rudder so I put a stainless steel prop protector ring on the outboard. As soon as I did this, I noticed my zinc getting coroded faster.. the metal ring probably creates a nice little galvanic circuit with the zinc. So.. the outboard prop is also always out the water. FYI, that little sail in the back was supposed to cut down on swinging but I dont think it did much at all.. dumped it.