|Topic Review (Newest First)|
|09-17-2009 09:03 PM|
Dufour 32 Jammed Rudder--3rd Update
Well, the bearing is out! Here is the next part of the story. The latest photos have been posted at Flickr:
Joujou Dufour 32's photosets on Flickr
After the last update, we undertook an effort to rotate the bearing 90º horizontally by continually moving the hammering point around counterclockwise 195º from the previous point. We were trying to expose more uncleaned bearing surface that could be cleaned. It did not work; we think the flanges were large enough to thwart us.
Penetrating oil was of very minor help.
Water ice was ineffective in shrinking the bearing. Only dry ice will do.
So, a decision point was reached: try dry ice again, or, knowing that I could obtain a replacement bearing, proceed with brute force to get the bearing out. I had handy a set of iron chisels, and a Dremel tool with attachments for cutting the bearing.
We started with the chisels. The 3/4" chisel imbedded itself into the flat edge of the bearing easily. At first the bearing was hard to budge, but then it turned more easily as the restraining material's surface diminished. We got near to the 90˚vertical rotation we were seeking. Next we used the chisels as bars to pry out more of the bearing until we could reach in to yank it out by hand.
Peering inside the housing, there was a substantial amount of light-colored, fine, granular powder. Apparently, this is the calcified algae that caused the lock up. The photos show it well. Also, it looks like the white distilled vinegar we used earlier never penetrated between the bearing and the housing.
(1) Clean, buff, and polish the aluminum housing.
(2) Clean the bearing, file down the chisel indentation; keep the bearing as a back-up.
(3) Install a replacement bearing—one is on order.
(4) Give Dufour an earful about this problem.
|08-26-2009 04:20 PM|
There seems to be some confusion about the materials. From the Ertalyte web site, it is most definitely NOT NYLON "Ertalyte® is an unreinforced, semi-crystalline thermoplastic polyester based on polyethylene terephthalate (PET-P)." it is a variation on PET, the material that soda bottles and polyfleece vests are made of.
Instead of packing the bearing with vinegar, pour in alcohol (any kind, highest proof you can) and then add in a slurry of dry ice chips. The alcohol conducts the cold without freezing, so you'll REALLY cold-shrink those parts.
You could so the same thing by applying a CO2 extinguisher--but the dry ice chips will be way cheaper and less fuss.
Usual precautions that dry ice disagress with eyes, flesh, etc. and high test alcohol vapors do all that and catch fire if you're smoking.
You might try calling the folks at Kroil or PBlaster and asking if their products will attack a calcium-aluminum problem, they're not just lubrications, they chemically break corrosion problems.
The whole thing still sounds odd, I'd expect calcified anything to basically act like sand and abrade down any type of plastic bearing material, rather than lock it up. Whatever you rebuild with, you might consider packing the bearing area with Dupont Krytox grease. Kyrtox is expensive, but chemically inert, even in a pure sulpur or chlorine or oxygen environment. It is thermally stable from -70F to 700F, and doesn't migrate. Has no effect on rubber, plastics, or petrochemical seals or parts, so it should lube your new bearings as well or better than anything else on the planet, or at least, longer than anything else. And of course, it will smother any algae that enter the rudder tube.
|08-26-2009 04:07 PM|
Dufour 32 Jammed Rudder--2nd Update
Well, there is progress to report. My latest photos have been added at Flickr:
Joujou Dufour 32's photosets on Flickr
Continuing the tale, after 6 days of soaking in distilled vinegar, we pulled the Shaw plug, placed a piece of hard wood against the bearing, struck it repeatedly with a heavy ball-peen hammer, with no movement of the bearing.
Next we assembled a one foot piece of iron pipe with a short PVC sleeve that fit closely in the hole of the bearing; struck the pipe repeatedly with the hammer, hoping the leverage would be adequate to break the bearing free. Again, no luck.
Out of frustration at this point, I started thinking about destroying the bearing with a reciprocating saw and chisels. BUT I’d risk damaging the aluminum housing.
Called Loughborough Marine Interests, LLC, in Newport, RI, the sole USA distributor of JP3 bearings, and spoke with David. He was very helpful. Found out that the cause of the lockup is calcified algae; he knows of 3 other sailboats currently with the same problem. David explained that JP3 bearing tolerances are too close, allowing the smallest foreign materials to restrict the rudder shaft and movement of the bearing. For 5 years he’s been recommending to the JP3 folks in France that they adjust the tolerances, but they have been unresponsive. David suggested continuing on the chemical route, to avoid damaging the housing. I also ordered a new 60 mm bearing, just in case, though the order can not go in until the French return from their August vacations.
David advised that the bearing is made of a neutral nylon, called “Ertalyte”, which is extremely stable. Full detail is at:
Ertalyte® PET-P & Ertalyte® TX
My friends and I could find no chemical that would attack calcium while being inert to aluminum except for distilled vinegar, which is diluted acetic acid.
A Coast Guard friend suggested shrinking the nylon bearing a bit by placing dry ice inside the opening to chill it, thinking the calcium bond should then be easier to break. We tried it. A 20 minute first attempt produced hairline movement. A 40 minute second chilling, while we had lunch, did the trick. Though still needing the iron pipe and hammer, we could move the bearing fore & aft and starboard to port. We continued to bathe the bearing in vinegar, cleaning surfaces as they were exposed. (See the relevant photos on Flickr.)
At the end the day, we left Joujou with the Shaw plug back in, and the rudder tube filled with distilled vinegar.
Next steps: Return, and continue moving the bearing, and cleaning with vinegar. We need to reach a point where we can flip the bearing 90º so that we can drop it out. After that, more cleaning, and assessing the condition of the bearing and housing.
|08-10-2009 04:52 PM|
The JP3 site seems to indicate those bearings are stainless steel, or have subtantial stainless parts in them. If your rudder stock is aluminum, then the white deposits you see may be the result of dissimilar metal corrosion. Putting aluminum and stainless together in an electroylte (salt water) is generally considered an extremely bad idea. Even with gobs of TefGel or other corrosion-preventive goop.
IF DuFour spec'd it that way...I'd assume "It seemed like a good idea at the time" to someone there. But you might want to check with the factory to find out if that really was their idea, and if they use anything special to prevent problems with it.
And needless to say--if it is not calcium, the cleaners you are using probably won't do anything, you'll have to take a whole other solution to it. (Pun intended.)
|08-10-2009 04:39 PM|
Dufour 32 Jammed Rudder--1st Update
Well, it's a lot less bad than I anticipated. Two sailing companions and I, by removing the restraints on the rudder shaft and twisting the rudder back & forth, managed to get the rudder down to the ground, thereby exposing about half of the shaft (made of aluminum, it turns out). Happily, it was NOT bent. But the lower self-aligning bearing (inside an aluminum housing bonded into the hull) was encrusted with dried marine contamination, and locked in place. We believe there to be some calcium deposits as well, locking the bearing.
Photos are at:
Joujou Dufour 32's photosets on Flickr
The self-aligning bearings are made by JP3 Steering Systems, another French company, and used by Dufour. The JP3 web site:
Which one ?
For a really cool animation of how the self-aligning bearing removes, see:
A few days later I had the sailboat raised two feet higher by the marina’s travel lift, letting us slip the rudder shaft out completely.
Using stiff brushes with metal and soft abrasive cleaners, we removed as much visable dirt from the bearing and housing as possible where we could manage to reach. Next step was to loosen the bearing. We sprayed Oxi-clean solution plus Fantastic cleaner with Oxi-clean up into the rudder tube, trying to get the liquid to loosen the bond between the bearing and the aluminum housing. Then with a stick of wood and a hammer, we tried to nudge the edge of the bearing, hoping it would start to rotate (so we that could eventually remove it). With thirty minutes of effort, it moved a hair. Very frustrating.
Next steps: Order a Shaw plug (Snap-tite 2-3/8" x 1-3/16" Expandable Rubber Plug) to plug the hole in the bearing. Fill the rudder tube with Oxi-clean solution. Then wait a few days. Try again to loosen the bearing. Maybe nudge it with a metal pipe just under the 60mm hole diameter in size. If not successful, try again with distilled vinegar, thinking it may dissolve the calcium that could be locking the bearing.
|07-24-2009 03:39 PM|
|dongreerps||Our boat suffered a rudder failure. The yard recommended hauling the boat, etc, at significant cost. At the suggestion of a friendly marina manager, when the new rudder was available, took the boat into slightly deeper water, put a diver over the side, loosened the retaining gear, had the diver weight the rudder, and pulled it down out of the boat. Then took the new rudder under the boat, and floated it up into place. Much easier than a haul out. Of course we were in warm waters. . . with excellent visibility.|
|07-24-2009 03:13 PM|
Riggers usually do rigging, the wires and cables above deck on a boat.
Rudders are plain old boatyard work. Usually a plain old mechanic does the job. Either you pay the yard to hoist you in the air while they drop the rudder, then you park the boat on jackstands while repairing things, and hoist again to refit, Or you find a yard that will let you dig a pit under your rudder, and you simply park the boat, dig a pit, drop out the rudder, and start work.
Either way you need to look for hull damage and damage to the rudder tube, not just the bearings. And probable damage to the rudder, because even a hairline crack can let in enough water to lead to total failure down the line. You may very well need a total rudder replacement or rebuild, as well as work to the rudder tube and hull, unless it was a very soft grounding and the rudder just pushed down into the bottom. If the shaft was bent, it probably would not turn smoothly. If it turns smoothly, it should still be inspected very closely but the odds are it isn't bent.
Unless the rudder moves freely and normally--odds are there's more repairing needed than you might think.
|07-24-2009 02:18 PM|
Dufour 32 Jammed Rudder
I'm looking for a rigger in the Baltimore, MD area who has some experience with removal & repair of sailboat rudders. My Dufour was buffetted by gale winds in late October 2008 while sitting on the bottom in very low water in my slip at Middle River. Rudder bearings are probably deformed; can't tell if the shaft is bent. Need to remove rudder, then make assessment about what to do.