Rudder support repair on Newbie's 86 Rider

[Kma4444]

Hey all, I am a friend of Newbie Girl on here and I have been helping her with her new acquisition. It's a beautiful 86 SunSport Rider, great boat that she's really enjoyed.

It had a leak that was from the rudder area, where it came through the floor, not the actual rudder shaft. The previous owner had thought he had fixed the area with some epoxy, evidently applied from under the boat.

I took the boat home and pulled the rudder assembly out and cleaned out the old sealer and resealed it into the hull. New O-rings in the bearing housing and carried it back to the lake.

It worked perfectly for a day that included a long ride. Late that day she went skiing and came back in with a lot of water in the boat. On inspection, the rudder assembly was loose in the hull, not good and took it out for the weekend.

I brought it back and these pics will show what I found and how I fixed it.

Got the gas tank out and it all looked like this.


http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Rudderbefore.jpg

After a little cleaning;

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Rudderclean.jpg

[Kma4444]

She got the boat knowing it was gonna need a floor and most likely stringer repair but the summer has too much time left in it to wait so she needed her all mended up.

What's not obvious in this pic is that the rear of the fibreglass cap over the core material is cut away around the drain plug area exposing the wood core. It also doesn't show that the cap is not bonded to the transom at all.

This pic shows it a little better.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Glassremoved.jpg

And this one.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Glassandwood.jpg

You can see, on the gray, glass part, the cutout for the drain plug and the couple of small pieces of glass that had initially been bonded to the transom. It was completely broken free and with the soft wood, the entire support was moving in the hull. You could grab the rudder and move it fore and aft an inch or so.

[Kma4444]

To be clear, I did no cutting or grinding on the rear part of that glass, I just cut the sides and front and pulled it out of the boat. The bedding material had evidently been all that was holding the rudder in place as the wood had long since gone all gooey. The reseal job lasted until the rudder had flexed enough and broken the sealer's bond, then the prop wash just pumped water into the bilge.

Then I took and ground the area to clean up the bedding material, actually just got it all out of there as it had cracks in it through to the hull. This let me clean up the edges and rough up the transom and stringers. On the stringers, they are relatively solid, but the foam is just soaked and the floor is soft in a couple spots so the winter floor/stringer redo is definitely on.

I took a piece of 3/8" 6061 aluminum and made a new rudder support, I broke it slightly to fit the shape of the hull better so I wouldn't need so much bedding material.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Ruddersupportfitted.jpg

The ends of the plate are slightly up where I broke the plate. I milled the hole in the plate and threaded it for the rudder bearing to bolt to. The bolts are in there as I made a spacer for the bottom of the plate that is shaped the same as the rudder bearing. This will give me a recess that the bearing will fit into. I covered the spacer with vacuum bagging film so it wouldn't be a permanent part of the boat. I also taped the hole in the hull from the bottom so the goop wouldn't run out and compromise my bedding area.

[Kma4444]

Then I took and cut 11 oz carbon fiber strips and pieces that would go under the plate and applied epoxy to bond them to the hull. I used the strips to bridge some of the gap between the lowest part of the hull and the plate. The pieces of carbon went under the sides of the plate as little more support. I then made an epoxy and cotton flocking slurry and buttered the bottom of the plate heavily. The plate was then placed in the hull and wiggled and pressed into place, forcing the compound out the sides and bottom to completely bed the plate to the hull.

I then used more slurry to bridge the transition from the carbon on the hull to the plate so there would be no gaps when I laid up over top of the plate. Then I capped the plate with 4 layers of the 11oz carbon and epoxy resin that I carried up onto the transom and stringers.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Ruddercarbondone.jpg

And what it looked like from the bottom after I removed the spacer and cleaned up the edges.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Bottomviewdone.jpg

The black you see in the perimeter of the opening are little bits of carbon, not holes. The bedding compound was completely around the opening.

[Kma4444]

And the whole mess put back together.

http://i526.photobucket.com/albums/cc341/kma4444/Maxine/Rudderdone.jpg

She got another 5 hours or so of use this weekend and leaked not a drop. The only time the pump ran was after the rain storm. So that part is done and won't have to be fooled with when the structure gets rebuilt.

It was a fitting repair for such a nice old boat.

[wotan2525]

Nice work and great thread!! Keep us all updated and take pictures, you must be a pretty handy guy. Though this probably isn't the "correct" method, I can see nothing wrong with it and love the ingenuity!

[mapleleaf]

Def. thinking outta the fiberglass box!!! Looks amazing and should hold up for I dunno EVER!!!! Nothing like a good friend!!!!

[Newbie girl]

Wotan and Maple leaf, you are correct - KMA is ingenious and has lots of ideas. Maxine was a happy girl this weekend and I surfed for the first time behind her with our flintstone ballast. It was just a quick trial to see how she did and for me to get my "surfing" fix. He had already come up with a possible idea for ballast in the floor when we redo the floor and the stingers.

[Kma4444]

It was a pretty quick and easy enough fix and it was nice to get Newbie's boat back on the water. I do expect it will last a while and is likely the strongest part of the boat. I wouldn't have chosen to use carbon fiber if I didn't have it around but the scraps were just right for this spot. The epoxy resin on the other hand would be my only choice for this kind of work.

I do a fair amount of composites work, race car stuff mostly. This was nice as I didn't have to make a plug, then a mold, then the part, which of course has to be vacuum bagged and then,,,,, bla bla bla. The rework this winter should be interesting. I'll get pics when I do the work. It will likely be a little unconventional also. I don't expect to use carbon fiber in most of it though, the ol gal can handle the few extra pounds I'm sure. Maybe I'll pop a few pieces of carbon here and there for appearance purposes.

And it's easy to be nice to Newbie, she's the bomb.

[sybrmike]

Nice work and nice gesture helping out a fellow boater.

Kevlar (did the 86 have the Supratrac hull?) and now carbon fiber. What's next - some titanium? Is it a boat or a rocket ship. And I thought I went a little exotic with a plug and bagged coremat layup in my new ski locker insert.

Again, nice work getting back on the water so quickly (I should be so lucky...)

[Okie Boarder]

Looks pretty good. I've heard you have to be careful with metal against the hull, but if you broke the edges and bedded it in thick, I'm sure the worries about that go out the window.

I'm sure we'll all be watching to see how the rebuild goes this winter. Start a thread when the time comes and post lots of pictures. The in-floor ballast idea is something that I'm sure many of us would like to hear about.

[Kma4444]

This one did have two layers of a VERY open weave kevlar in the piece I cut out. It can't hurt but it's not a terribly substantial amount of it. Kevlar is an amazing material, strong beyond belief and a devil to cut. I use it in a lot of my composite structures, stops a carbon piece from shattering when the driver prangs the car off of something. It will still break, but the pieces are bigger which is good.

Yeah Okie, I did think about the metal against the hull, that was part of the reason I broke the plate so no edges would be right against the hull. Also the carbon fiber under the plate and the substantial bedding material. I'm thinking it will distribute any loads over a large area and not cause a hard point on the hull in a small area. The plan was to make it a solid area not just a stiff plate against a flexing hull. I'll keep an eye on it but I don't foresee any problems.

The underfloor ballast is coming together nicely in my head, I can't wait to run some math on it. Should be fun.

Thanks for the comments all.

I will start a thread when the massacre begins!!!!

[wotan2525]

If you go with in-floor ballast, I really think you should look into a gravity fed system. Almost no moving parts and fills/empties in seconds rather than minutes.

www.mbsports.net/accessory_view.asp?accessory=ballast

[Kma4444]

That should complete my plan, BRILLIANT!!!! I wonder if I would have thought of that myself?

Thanks a lot for that link, that's really gonna make it a neat setup.

[wotan2525]

Yep. Should be pretty simple... There was a thread on wakeworld where someone went to the MB factory and took some shots of what the tanks looked like under the floor. Pretty self explanatory, really -- just make sure you put a bunch of baffles in there so that the water doesn't slosh around too bad if they're not totally full. Excited to see how you do it!

[Kma4444]

Thanx again for that link. I had figured on baffling the tanks for that exact reason. Don't hesitate to make any suggestions, I'm happy to hear them. Can't wait to see how she comes out myself!

[Salty87]

nice repair!

check these videos for info on gravity fed system...
http://www.mikemurphyentinc.com/purevert-vid1.html

[87SunSportMikeyD]

I meant to post this earlier, but looks like VERY high quality work. Thanks for taking the time to document and share in these forums! Very good stuff to read AND see!

[Kma4444]

Thanks Salty for the videos, they gave me another idea for my valves.

Thanks Mikey, I'll start another thread when the real work begins.