Tohatsu 18HP anode

[mestrezat]

Not sure if this is the right place to post this question but here goes. I've got a Tohatsu 18hp two stroke outboard. The anode on the bottom near the prop has worn out. While trying to unscrew the bolt, it sheared off. Any suggestions on how to get a salt water encrusted sheared off bolt to unscrew?

[senormechanico]

If you have anything to grab what's left, first soak in WD40 for awhile, then using heat (propane torch) it should come out with vise grips.

If it's broken off flush, you'll need to drill and after the above soak, use an easy out tool.

Good luck.

[mestrezat]

Follow up.
I soaked it in PB Blaster over night and then took my propane torch to it and heated up the stub of the bolt. Put on vice grips and it still won't budge. Tried different vice grips. Chiseled away where the bolt screws into the outboard all with no success. Vice grips are now pealing away the threads on the bolt.
Other than drilling out the bolt(real pain) any other suggestions?

[HopCar]

Is this a stainless stud screwed into aluminum? If so you need to heat the aluminum, not the stainless. Heating the aluminum will enlarge the hole, good. Heating the stud will enlarge the stud, bad.

Another way to go about it is to hit the stud with CRC Freeze-Off. This should chill the stud and make it shrink. I've never tried Freeze Off. If you try it, let us know how it works.

When you put the new stud in, coat the threads with Permatex Three. It will prevent it from happening again. I learned that trick when I hung out in an outboard shop as a teenager.

[mestrezat]

I'll be hauling the engine on deck this afternoon and trying again, this time concentrating on the aluminum instead of the bolt. May have to take off the prop to really get at it. Thanks for the suggestions but being in Curaçao, some things aren't available.

[Simi 60]

Instead of replacing with a small original anode consider a much larger bolt through on the cav plate .

I made a larger permatrim style trim plate for my motor and through that bolted a large circle rudder anode.

[mestrezat]

Had help from a fellow cruiser and hauled the motor on his deck. Tried cuttin slot in the bolt but all that did was break the bit on his impact driver. Time to just drill another hole and put on a different zinc as the last poster wrote. Let's get on with life.