Re: mounting zinc on an aluminium hull
Hi Readytogo,<br /><br />You can get info on the principles of galvanic corrosion from FAQ - 'Dealing With Corrosion ...'<br /><br />Short answer is this: <br /><br />You need to fit a lump of metal to your boat that will get eaten away (sacrificed) at a faster rate than the aluminum. The wider apart on the galvanic table the two metals are, the better this will work. Fitted in proximity is good (like fitting a zinc to an outboard leg, which will protect the hull, prop, boarding ladder, etc also), but fitting it to the hull by direct contact (riveting, bolting, screwing) is better.<br /><br />If your hull is suffering, be generous with anode sizing. The level of protection is dependent on both anode material and size. Keep the anode cleaned of any oxide buildup (furry-looking surface) with a file if needed, and replace it when it's half gone. I don't replace mine when half gone - I just bolt on a new one and let the old one vanish to nothing.<br /><br />One other detail. Always use fixings that are more 'noble' than the anode itself, otherwise they may corrode first and you lose your anode.
