J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Rudder(s)

Thanks, I was just curious. I have to believe that with a foam core yours would be much, much lighter than mine.

I think if a person was inclined they could use the same technique I used to mill a foam core. I think you would just want to use a full face respirator because the dust would be even nastier than the 25 Lbs. of white oak dust I spread all over the shop.

I don't have any point of reference with monohulls, but I suspect that a balanced rudder is also faster in light air. The lower aspect ratio wouldn't stall as easily and may help prevent overcorrection that wastes boat speed.

My balanced rudder is wood cored, no foam. It's decently heavy.

David, I wonder if a balanced rudder is faster in light air? On the J/30 when it's light, you're doing everything possible to get some feel in the helm. Balanced makes it just that more difficult.

Dennis that is interesting. Again I don't have a point of reference with the J30 or monohulls. My sailing experience is with high performance catamarans. I would expect that in light air the "feel" of the rudder and its effects would always be very minimal. However, what I think I would be more interested in is the actual result of minor helm input movements in changing the track angle of the boat. A wider (lower aspect ratio) rudder at slow speeds has to be more effective at changing the angle than the higher aspect ratio rudder. This would be the result of both the increased surface area, in my balanced rudder that is about 144 square inches more than the std. and then the much lower stall angle with this increased width. At these very low speeds the "balanced" feature isn't as important as the increased surface area and the stall angles that come with the increased width and surface area.

At higher speeds the penalty for this balanced design as I have laid it out is the increase in wetted surface area and that is then traded for reduced helming effort, which was my primary goal.

This has been a very informative thread. Thanks for posting Dave! I am interested to see how your new rudder will react on the boat. It certainly should outlast her...

I will likely be in the market for a new rudder next year and have thought about going with a balanced rudder, either from Competition Composites in Canada (Phils Foils) or RudderCraft in Boise (IdaSailor). I know that Waterline Systems is now selling original rudders for what looks to be a fair price, but I believe they still use a balsa core. The Competition Composites or RudderCraft fully composite rudders seem to be a better option for me.

Waterline systems doesn't have anything from inventory or drawings after the US Watercraft foreclosure auction. I spoke with J/Boats and the disposition of J/Boats intellectual property formery on site at TPI where US Watercraft and Waterline Systems were located has not yet been dispositioned. Waterline systems has relocated and does not have the J/Boats drawings in their possession. They may eventually get it, but until that happens, don't count on getting a rudder or anything

After rereading this I realized it was a rant, but sometimes you just have to get it off your chest.


I am trying to take a really long view of all the projects I'm doing on MaJic Carpet. I am not anti balsa, but there is no way I would spend a big chunk of change on a balsa cored rudder even if I was concerned with maintaining OD. While most of the strength is in the skin, why would you want to haul around a soggy compromised rudder. The first time the skin is penetrated below the waterline, or maybe even above it the core will become saturated and begin the cooking process to turn the balsa core to mush. At that point you have reduced the strength significantly. If I were paying for one of these things I would go with a foam core and the second choice would be wood. At least with wood when the skin is penetrated the movement of the moisture is slower and there is still substantial compressive strength in the core for a long time so the skin has support and the lateral strength required.

I have no idea how it was done, but one of the PO's sometime over the years managed to impact the bottom of the rudder pretty good. The front bottom corner had been crushed inward (the question could be asked if the balsa was already soggy so it couldn't support the skin, or if it was just a big hit). So the source of the water was this small hole and the jillion blisters on the skin. I have no idea how long this condition had existed, maybe the rudder would have held up like that for a long time. When I cut a chunk of the skin away on the rudder the balsa was black, but firm, not as bad as the area around the exhaust which was black soup. I want to be able to sail this boat hard when necessary and do not want to have any fear that the rudder could give way. That would be a very bad day sailing for sure.

Short anti-rant...

Balsa works fine if properly epoxy isolated. The issues with wet core can always be traced to improper isolation, or not properly fixing damage that is significant enough to crack the fiberglass.

/rant off

Well, that settles that question. I will stick with the CC or Ruddercraft rudder.

Coastie,
I agree with you. Since you are going to all of the trouble anyhow, there is no reason to put balsa back under the water. Your rudder should be good to go for a long, long time.

Bill,
I agree that balsa can easily be managed by isolation and I am isolating like crazy the hull of MaJic Carpet. I would however suspect that there are very few original balsa core rudders that are not saturated (even on the best maintained boats). Even without the impact mine suffered there were two other areas that were not isolated, the bolts for the straps were sealed over with what looked like 5200, but the holes themselves were not isolated. The other area that was letting water into the core was the hole for the tiller and I suspect that one gets by most owners. The hole for my tiller was wallowed out and the core was exposed. A few years of rain running down the tiller handle would have saturated the core too.

The rudder is like the area around the exhaust that gets directly exposed to sunlight. So when they are wet the internal temp of the core can and does go way up and starts cooking the wet balsa into a black stew.

I have one other rant issue I will get to one of these days, why the h..... did they screw through the inner skin in so many places? Where I can find and get to these screws I am removing them, sealing them up and putting a simple wood block in place to reattach the straps to.