replacing an anode bolt...

[LeonF]

Trying to replace the hull anode has turned into a major job. The nut refused to come off at the tip, ended up turning the bolt and breaking the seal, so going the whole hog and replacing the bolt. Just wondering what to use to seal it with?? Sika is too adhesive if ever I have need to do the job again...and should I be glueing the squate steel plate on the outside end of the bolt to the hull ? Any advice appreciated.

 

[pvb]

Two nuts next time...

Someone once told me you should always use two nuts on each anode stud. You can then put a spanner on the nut nearer the hull to hold it while you undo the outer nut with a second spanner. This should prevent the stud turning. Undoing the outer nut scrapes off all the nastiness on the thread, making it an easy job to remove the second nut.

And I'd use Sikaflex or similar to seal it.

 

[guernseyman]

Well, I take anode and bolts off every year to clean them up (a good electrical connection is needed) and assess if any part needs replacing.
Sika 292 is the strong adhesive one and not recommended for use below; Sika 291 is ideal.
My bolts are a tight fit through the hull and I use any sealant handy, except 292; never had a drop of water through. I circle the square plate with whatever the day before, treating it as the primary seal, with sealant being forced upwards to fill any void as the nut inside is tightened.

 

[ditchcrawler]

The MG Duff website says "apply a generous amount of marine grade silicone sealant to the shank & collar where the stud touches the hull to ensure a good seal". I use Dow Corning marine silicone which costs about a fiver for a small tube.

 

[LeonF]

Thanks guys. Going to use Purflex Polyurethane sealant/adhesive. The MG Duff website has lots of useful info.