rudder tube material

gkny

Member
345
26
I am replacing some rudder bearings.  The old rudder tube appears to have been pvc and it slipped into the top of the rudder bearing housing.  The whole housing fits into a socket in the hull which extends 6 or 7" above the inside of the hull.  This makes the top of the socket something like 10" above the waterline.  I had to cut out the old rudder tube to get the bearing housing out.  I can find stock tubes of the right dimensions in polycarbonate, aluminum, anodized aluminum, and fiberglass.  Aluminum would be the least expensive and lightest and fiberglass the most expensive and heavier.  The rudder bearing housing is aluminum.  I am not sure about how much of an issue corrosion would be with the aluminum.  Bonding might be an issue with the polycarbonate.  The rudder tube extends about 16" above the bearing and ends just below the fitting for the rod that goes to the pedestal.  

 

gkny

Member
345
26
A picture would be useful. What kind of bearing? What kind of rudder shaft? The bearing fits in the socket, not in the tube?
The bearing is a jefa bearing.  The roller bearing fits into the bottom of the housing and the tube fits into the top of the housing which has an internal stop that separates the rudder tube from the bearing itself (along with a delrin washer).  The whole bearing assembly fits into a socket in the hull.  The rudder tube stick up through the socket or built up part of the hull and is sealed with 5200 caulk..  The rudder shaft is aluminum.  

 

gkny

Member
345
26
Pics? If it's just there to keep the water at bay if the bellows fails, go with original?
 
I have included a picture of the interior which shows the old PVC tube as it was installed.  The tube is about 11" from where it emerges from the built up socket in the hull.

rudder tube interior of boat 2.jpg

 

gkny

Member
345
26
was there a rudder tube boot of some sort? or was it high enough that water didn't come in?
It is high enough that water did not come in.  There is a fitting that clamps onto the rudder post about 2" above the top of the tube that the steering arm in the picture attaches to.

 

Raz'r

Super Anarchist
60,982
4,980
De Nile
It is high enough that water did not come in.  There is a fitting that clamps onto the rudder post about 2" above the top of the tube that the steering arm in the picture attaches to.
Then if it's not holding anything, pvc would be fine.

Me, I'd put in a glass tube and a rudder boot, but I sail offshore....

 

Coolerking

Member
436
38
LBC
Glass tube, one piece, with a wetsuit boot with hose clamps holding the boot on,  toss the pvc.

But actually there is much more to this whole thing, like Set screws, laminate schedules,  anti corrosion chemicals,  upper bearing alignment.

From and old offshore guy....

 

El Borracho

Sam’s friend
6,438
2,454
Pacific Rim
My tube high enough that water does not come in. However the problem is air rushing out. At speed it makes a horrendous vacuum cleaner noise and can’t be any benefit to steerage, either. So there is a G-10 washer...a doughnut...that rests there. Loose but well-fitted. From your pic I would think adding a rubber boot unnecessary.

 
My tube high enough that water does not come in. However the problem is air rushing out. At speed it makes a horrendous vacuum cleaner noise and can’t be any benefit to steerage, either. So there is a G-10 washer...a doughnut...that rests there. Loose but well-fitted. From your pic I would think adding a rubber boot unnecessary.
I'm not sure, but from my experience that vacuum cleaner noise is the whooshing of the money leaving my wallet. :)

 
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