r25 1 1/4 prop anode screw

jimbeam

Well-known member
Joined
Aug 21, 2019
Messages
172
Fluid Motion Model
C-248 C
Hull Identification Number
FMLT2545G708
Vessel Name
waite & sea
Checked the prop anode and it was totally gone and the screw that attaches it. Got a new anode but what screw should I get? it is a 1/4 screw but what material should the screw be? Someone said don't use stainless.
jimbeam
R25 1 1/4 shaft
 
There's quite a few posts on this topic so I'll try not to repeat.

Just changed mine using the screw and star washer that comes with the anode as well as a touch of Loctite. I change every 6 months and haven't lost one yet.

Stay Safe
 
1/4-20 stainless steel screw. When screwing into the prop nut confirm the length of the screw to have enough thread contact for full thread engagement but not to long that it will bottom out giving a feel of tightness but not clamping the anode in place. I recommend using this order of installation anode, large fender washer, a small washer, bolt. This will help maintain the clamping force when there is some decay of the anode. A thread locker as Chimo stated will also help retain the bolt. One other item to confirm is the prop nut is clean, all corrosion and marine growth removed so that the anode fits and shoulders properly to the nut. Maintaining good continuity to the nut so it is able to protect the Prop and prop shaft.
 
From my maintenance notes on a 2012 R27 concerning the prop anode:

Prop anode CMPND 1 1/4”
Bolt 5/16”-18 1/4” hex head socket screw. About 2”

The anode and bolt came from boatzincs.com. The bolt is stainless steel with an internal tooth lock washer. I use an aluminum anode because I boat in both fresh and salt water.
 
CaspersCruiser":20fwags2 said:
From my maintenance notes on a 2012 R27 concerning the prop anode:

Prop anode CMPND 1 1/4”
Bolt 5/16”-18 1/4” hex head. About 2”

The anode and bolt came from boatzincs.com. The bolt is stainless steel with an internal tooth lock washer. I use an aluminum anode because I boat in both fresh and salt water.

Bill, you are right, 1/4" hex drive 5/16 /18 bolt
 
An obvious comment about prop nut. It shortens as it corrodes getting loose probably no longer acting its sCrificial role as it makes poor contact. Like Bb marine I use a large stainless washer, then a stainless thrust washer (hard to find) then a smaller washer. Seems to help this not great system of parts from premature failure.
 
I have lost the anode even when using the large stainless fender washer. Last season I used three small stainless washers inside the anode along with the standard hex socket screw and toothed washer (with thread locker) on the outside (under the socket screw head). This worked great! This method is not dependent on the overall length of the anode so as it erodes it does not get loose. The three washers fill the difference between the castle nut length and the anode interior length (they are not the same). The anode is then held firm between the stainless flat washers inside and the toothed washer outside. Those surfaces don’t seem to erode yet still provide electrical contact. After 6 months the anode was as tight as the day I put it on!

Curt
 
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