Can not remove trim tab anode

[timschap]

2004 225HP Mercury four stroke. I tried to remove the trim tab anode and I can not budge the bolt. I've tried heat but still will not budge. Looks like someone tried before because the allen head is buggered up (wrench will fit in but with a lot of pressure it jumps). Assume I need to cold chisel it out but want to see if anyone has other ideas

 

[robert graham]

They may have had a problem with bolts coming loose and trim tab falling off...decided to use permanent Loctite on bolt....may have to cut it off....

 

[harringtondav]

Per Robert Graham's reply above, flame heat is often required to loosen Loctite, especially when corrosion is at play. Try a propane soldering torch, map gas + oxy brazing torch, or a good 'ol oxy/acetylene rosebud.

If still a no-go try drilling out the bolt from the underside. My Alpha's flush anode bolt is visible. Don't know about a trim tab anode. Sneak up with at least two consecutively larger drills. The bolt is a Std. SS. If you ruin the anode, replacements aren't terribly expensive.