Rudder cracks - '81 Cherubini Hunter 36

Apr 7, 2014
8
Hunter 30 Nyack, NY
Although I am a H30 1981 owner we have similar problems.

This past winter I demounted my rudder to fix a similar problem. I say demount because the Skeg had to be dropped also.

The Starboard side of the rudder was terrible. Almost more cracks than good gellcoat. The Port side might have had 6 cracks. All cracks were predominatly horizontal. The holes that were drilled over the years to let water out showed no signs of H2O. I sounded the entire both sides and found one area toward the trailing edge about the size of a quarter, was delamed.


I didn't bother with the delam area. I picked all the cracks open to tight Gel Coat. This made some cracks 1/2inch wide or better. The smaller cracks were gouged by dremal tool. There was one area that the fiberglass under the gel was gouged and the foam exposed. The foam was in very good dry condition. No water.

I then proceeded to fill the gouged out areas with structural filler epoxy. After sanding and fairing, I applied a 4 oz. layer of cloth to the whole side. Likewise the other side.

Now the rudder is reinstalled and bottom painted. lets see at the end of this season if the rudder holds its shape.

I too read about rudders setting in the sun and that a dark paint while setting on the hard tended to do something to make the rudder crack. Whether it has something to do with shrinkage of the gel coat or the foam expanding I do not know. I can tell you one thing, the gel coat is quite thick for such a small piece. I just wonder if that is a factor. I'll enclose a before and after of the rudder. The after shows the underlying structural fill. This was before bottom paint. The before was when I had the boat soda blasted to get everything off. I then found out there was a barrier coat on the hull.

I would think that if your rudder sounded well than a simple repair should work.
 

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tmjb

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Mar 13, 2012
222
Hunter 36C Glen Cove
Apologies for the delayed response. I've been having trouble accessing the site.

Thanks so much for this which is great to know. I would like to try something similar. However I really don't feel I have time to take my rudder off this season. Is it practical to add the 4oz fabric while the rudder is still in place?

Also what type if Dremrl but did you use to rout out the cracks? I started with a can opener and it was tough going.
 
Apr 7, 2014
8
Hunter 30 Nyack, NY
Apologies for the delayed response. I've been having trouble accessing the site.

Thanks so much for this which is great to know. I would like to try something similar. However I really don't feel I have time to take my rudder off this season. Is it practical to add the 4oz fabric while the rudder is still in place?

Also what type if Dremrl but did you use to rout out the cracks? I started with a can opener and it was tough going.
The 4 oz is better done horizontal. I used a small carbide tool with dremal. Freehand it making sure you get all the debonded gel coat. Flare the gouges so they bond better. You can probably use the thick epoxy now then next winter take the bottom paint off and lay rudder horizontal to do one side at a time with cloth. Remember to use unthickened to prime the groves and exposed fiber matt. Good luck. Remember, you can't hurt the rudder, just use good epoxy to repair.
 

tmjb

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Mar 13, 2012
222
Hunter 36C Glen Cove
The red is dust from sanding red antifouling. The blue grey is barrier coat.

The starboard side has a little cracking but not much. The port side has significantly more but not as bad as others I have seen.

Where wide enough to see into (many are very thin) the cracks appear to be through gelcoat exposing fiberglass mat beneath.

I am thinking that for this season with local trips only, in order to get in the water, I should be able to get away with routing out the cracks, filling with structural filler, faring where necessary and painting with barrier coat.

My plan would be to do a more permanent repair next winter.

Thoughts?
 

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May 11, 2014
30
Hunter 27 Traverse City
I am in the process of dealing with same issue on my '83. I used a dremel to clean up the cracks and the foam is mostly dry. I made the mistake of trying to use a cordless dremel to do the work so an hour job turned into the entire weekend. It's a good thing I had plenty of other stuff to work on in between battery charges. : ) This week I will start filling with Interlux watertite epoxy.
 

tmjb

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Mar 13, 2012
222
Hunter 36C Glen Cove
I am in the process of dealing with same issue on my '83. I used a dremel to clean up the cracks and the foam is mostly dry. I made the mistake of trying to use a cordless dremel to do the work so an hour job turned into the entire weekend. It's a good thing I had plenty of other stuff to work on in between battery charges. : ) This week I will start filling with Interlux watertite epoxy.
I routed the cracks on mine with a Dremel this weekend and filled with 3M structural filler (photos attached after routing then after filler). I plan to fair and paint with Interrprotect before bottom painting and then keep my fingers crossed.
 

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Dec 8, 2014
13
Hunter 37 Cherubini Maine
I had the same issue on my 37 cutter (many cracks, only on one side). I found that only one side of the rudder had gelcoat laid down extremely thick and this is where all the cracks were. The other side had NO gelcoat whatsoever, just barrier coat and fiberglass. The cracks were only in the gel coat and did not affect the fiberglass. Therefore, we just routed out the cracks and filled them with interlux filler, barrier coated and painted. Hopefully we won't have any problems.
Cheers
 

tmjb

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Mar 13, 2012
222
Hunter 36C Glen Cove
Thanks for your input. I found gelcoat with what appears to be glass below on the highly cracked side, gelcoat and I don't know below on the other because it's barely cracked.

Keeping my fingers crossed.
 
Jun 8, 2004
994
C&C Frigate 36 St. Margarets Bay, Nova Scotia
I am sure both rudders will be fine unless you are out playing in hurricanes - then all bets are off :eek:

Has anyone determined if the H37C rudder and the H36 are the same? They sure look similar...
 
Mar 10, 2014
41
hunter27 hunter27 nassau
As a hobby I restore cherbini hunters, and Alberg 30s have done 4 so far and on my fifth, Pretty much restore them to 98% new condition. I have run into this on all but one hunter so far, These rudder cracks on one side of the rudder, or mostly one side.

One thing to consider that I have found with all 4 rudder repairs I've done is that when they build the rudders they often didn't center the blade stock (runs horizontal to the rudder post) on the inside in the middle of the rudder. They are often offset on direction or the other. why? dont know! seen it quite a few times. Also one of my feelings is that in the cherib 27 i've restored that have wheel steering, Often the Owners forget to make sure the cap on the emergency tiller is on...rain and spray will get into this spot and build up water in the rudder as the post runs unsealed right into the foam. Also often the seal from were the SS post enters the rudder stock starts leaking and will suck in water over time. The frame in the rudder is usually some SS stock of about 2" by 3/16 thick running horizontal to the SS rudder post. now when it freezes the wet foam between the flat rudder stock and the outside of the rudder causes horizontal cracks along the stock, usually on one side(the side the rudder is leaning inside towards. So often you get 2-4-6 horizontal cracks because there is usually 3-4 horizontal ribs to the ss post. Not saying this is what it is... but worth checking out.. I am sure you drilled some holes to check for dirty foam? should be white or off white foam,, if its yellow then its probably been wet... Hopefully you drilled some holes at the ends of each crack in the fiberglass to stop the travel of the crack. Just a thought.. make sure if you have emergency tiller to seal the cap and to check the area round the SS post and the rudder attachment and seal it up good with some 5200. In time this will have to be addressed to find the cause.. If and when you do, best course is to use a multi tool or grinder and cut out the fiberglass 2" from all edges and carefully peel it off and check out your rudder interior on the side of the most cracks. careful to peel off carefully so you can use the skin to re apply over the repairs.

On two of the 4 rudder repairs i did I found the the fiberglass skin thickness always varied from very thin to very thick and in between. If and when you repair the rudder feel free to wrap the whole rudder in another 1-3 layers of biaxial mat if its thin.
Just information not a verdict of what your actual problem is, but sadly it more appears that has probably happened.

Here is a picture of how the rudder in 1982 27 is designed inside.. very poor I think support inside.




if you look carefully you can see that the upper horizontal stock is close to the outside edge more than the other.. So if your rudder has water in it, it can develop the horizontal cracks your rudder is show due to the expansion of the horizontal stock. In all of the rudder repairs ive done on my boats or friends so far... they all sounded solid didnt have the obvious sound of delamination.

Good luck.. just more info to evaluate your problems