What do you mean by a "crack"?..... is the gel coat just cracked or is the rudder cracked thru? I've never done it but I don't think it's that easy to take out the rudder. You'll probably have to lift the boat.

You don't say where you are . If you're in a warm area where things aren't frozen, I've seen people drill drain holes in the bottom of the rudder, then let it drain for a good long time before re-plugging the holes (and fixing the leakage area).

If your just getting the boat, wasn't this caught in the survey?

jhenderson,
Welcome! You will LOVE your new boat. It does everything well. One thing you can do to help us help you is to create a "signature" for your posts. It should include some info about you and your boat. More specifically, the year and/or hull #. Check some of the other posts to get an idea of what should be included. You can add a signature by clicking on the "User CP" link in the blue bar above, and follow the instructions. MkI boats have a longer rudder post than MkII boats do. Hope this helps.

Well, J, if you think it best to take the rudder home, you should either ensure the boat is blocked high enough (is that riskier?) or plan to dig a hole (not sure if or when you can do that).

I wish I could tell you how much the rudder will drop before the post clears the hull. I guess it could easily be 18-24 inches or more.

I had to remove my rudder to install a new shaft. The boat had to be lifted. I would imaging you need at least 24". You can measure that by estimating the length of the rudder post from hull to the top of the post. Then see how much room there is at the bottom .

Hi and welcome
I recently replaced my rudder with a new one. I don't know how the boat is situated but if it is on the hard you would best served by getting a travel lift to tilt the back of the boat up and the front of the boat a bit down. It's not hard to remove it the only thing that is holding it on is the rudder post head and the wheel quadrant. It may be a bit difficult to remove the bolts holding the quadrant on since you are dealing with two dissimilar metals but it should come apart without to much effort. If you don't have a wing keel then I I believe you will need to raise the back at least 24~36 inches above where it sits. I don't recall exactly I just remember it seemed like the travel lift was about as high as it would go. Best of luck. BTW I didn't think I had a real problem till pull the rudder off, I was wrong

I have had my rudder off twice and I did it in the yard. If you are on Jack stands all you have to do is raise it a little at a time. I can't tell you how much I think about 4-6", but it worked for me. The hardest part is the collar at the top of the rudder post located under the deck plate. There is a bolt that goes through it. The problem I had was the collar was frozen on the rudder post and there is not that much room to fetch it with anything. I ended up using a dremel tool with a cut off wheel and cut the collar.

Next you are going to have to go below decks through the aft cabin and get the steering quadrant apart. You should probably get the collar off and the quadrant off first before you start jacking the boat. You should also block the rudder while you are disassembling. The rudder weighs a bit and perhaps you should have a friend vs. your wife tend to that job. Actually both times I did it alone. Before you start jacking take the blocking from the rudder and drop the rudder to the ground, then start jacking. You can also dig a hole if you are on soft ground and avoid the jacking.
Have fun and Good Luck!

On your C36, hull #741 the rudder post will extend 35 3/8" above the top of the rudder. That is according to info from Catalina Yachts and my own experience.

That sounds about right for a mark one the rudder extends to partially through the lazarithe which is a bit higher than how a mark2 is configured

I am not totally sure how the Catalina rudders are fabricated; but I do have experience with that kind of rudder repair on my previous boat - a Newport 30 and all I can say is - good luck! (and here is why...)
The rudder used to 'weep' water for 2-3 days after being put on the hard.
I removed the rudder and then removed some glass and gel coat around the cracked area, then re-glassed and barrier coated, before painting.
Two years later had a tough crossing of Georgia Strait in 25 knots close-hauled. On getting to our marina did a 90 deg turn at the dock and the boat kept going straight. :eek: Rudder stock had broken from the frame inside the rudder!! Had a new rudder built from scratch - it worked better than the old one ever did (less weather helm, etc (more balanced)

My point is: You can repair the crack and if you're confident no water has made it's way into the rudder you should be fine - but you can never know if there has been corrosion inside; and to what extent....

[QUOTE=HowLin;21392] - but you can never know if there has been corrosion inside; and to what extent....[/QUOTE]

That's largely true...

But we found a way - we noticed a small crack weeping rusty water, about 300mm below the 'notch' in the rudder. I lowered it with a 12mm line (photo) and drilled a circular hole to investigate. There is a MILD steel plate with holes to lighten it welded to the SS rudder stock. Ours looked OK, so I dried it and bogged it up.

We then sailed from New Zealand to Tonga, Fiji and New Caledonia, late 2012.

I noticed the 'bog' failed, and rusty water came out the whole circle of the patch. We hauled out in Noumea and had the whole shebang ground out and all new filler and a heavy fibreglass bandage put on. It appears a PO had run aground and bent the rudder - then did a cheap fix with a light skin of glass. Our rudder was just about to break off level with the bottom of the stock!