Dripless Shaft
- Thread starter frmreilly
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What was bad
What went bad on it. Far as I know there are three things possible. The rotor that turns with the shaft, the fixed face thats attached to the the bellows, or the bellows itself loosing it's strength. Let us know, just in case some others have a problem.
What went bad on it. Far as I know there are three things possible. The rotor that turns with the shaft, the fixed face thats attached to the the bellows, or the bellows itself loosing it's strength. Let us know, just in case some others have a problem.
Could have also been the set screws which are a one time use only..
I have a Ruland 316 SS clamp collar behind my rotor as added insurance..
Yup, and the seal, o-ring or otherwise that seals the rotary piece to the shaft, and the seal between the rotary face and its carrier. The one use set screws are mostly labeled as such because they have a thread locker on them from the manufacturer. If ya put some of the removable LockTite on em after inspection, they are OK to use again in a pinch.
It's not necessarily about the Loc-Tite. These screws have a circular volcano cone head with sharp edges. After the first use when it bites into the shaft the sharp points are dulled and may not bite into a shaft a second time.
This is my supply of new PSS set screws I keep on-board. Once tightened onto a shaft I never re-use one even in a pinch and even with my split collar. In a pinch they might hold but in a pinch can often lead to forgetting to replace them once the "pinch" is over..
As Maine Sail points out...the issue isn't the set screw backing out...but it not biting the shaft properly and getting a solid grip. If it doesn't bite securely, the collar it is holding in place can move. That's bad.
Don’t want to start a big Brouhaha but the hardness numbers of those screws are very much different than the hardness of the shafting (on a typical marine application) I agree absolutely one use on a hard steel shaft, like a 4140 or a 400 series stainless, but on 300 series stainless or stuff like Aquamet, or bronze, the screw bite will be sufficient for a couple or three applications IF the fit of the shaft to the collar or face holder is tight (.001-.002”). That said, I don’t have one of these on my boat.
the PO may have just let debris get between the collars when he pulled back on the bellows. happend to me when we installed the new pss on my boat. after the mild panic we flushed it again fully pushing back on the bellows then let it pop forward. no more leak every again. going on year 2 now. on looking.. i saw dead bugs floating in the bleed tube fixed that by bringing the tube below water level and flushing that too. i
Denise
Denise
AQ22 vs. 18/8
The shaft on my own boat is Aqualoy 22 which has a 302 Brinell (hardness) rating. 316 shafting has a Brinell rating of about 150, or less than half that of AQ22. 18/8 or 304 has a Brinell hardness of 160 and type 304L (more carbon added) is 140 Brinell..
With AQ22 being nearly twice as hard as 18/8 you can now see why PYI suggests the set screws only be used once. I have also confirmed this visually with rounded volcano heads after just one use. At one use they do score and set in the shafts surface but I would not presonally try it twice..
Actually those set screws are nothing more than 18/8 stainless which is basically type 304. Aquamet, Aqualoy or Nitronic 50 are harder (using the Brinell hardness scale) than 18/8 or 304...
The shaft on my own boat is Aqualoy 22 which has a 302 Brinell (hardness) rating. 316 shafting has a Brinell rating of about 150, or less than half that of AQ22. 18/8 or 304 has a Brinell hardness of 160 and type 304L (more carbon added) is 140 Brinell..
With AQ22 being nearly twice as hard as 18/8 you can now see why PYI suggests the set screws only be used once. I have also confirmed this visually with rounded volcano heads after just one use. At one use they do score and set in the shafts surface but I would not presonally try it twice..
The little black set screws are probably far more prone to corrosion though...and not likely to be removable after any time spent in the bilge of a sailboat.
Let's get back to the beginning .... what failed on the PSS seal? I have one and am quite curious.The little black set screws are probably far more prone to corrosion though...and not likely to be removable after any time spent in the bilge of a sailboat.
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