gilloverland Posted February 20, 2011 Share Posted February 20, 2011 Having recently had my 110 resprayed I want to avoid the corrosion spoiling my new paint job. This got me thinking about a sacrifcial anode, you can buy them from a well known auction site and from all chandlers (yacht / boating places). If it would work it would'nt be a lot of money to spend to keep the landy in good condition; As they corroded away you would change them as you would a filter at a service... So my question to anyone on this site with a better knowledge of chemistry than me is would this work? Would I need a zinc anode or a magnesium one ? Should it be connected to the chassis or the body work or both? Presumably I would need one per door too? This brings me to another interesting question - Does the bodywork last longer on a defender that is fitted with a galvanised chassis? - my theory being the chassis IS the anode and saves the body? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 20, 2011 Share Posted February 20, 2011 The sacrificial anode only works when it is fully submerged so it isnt going to work on a LR. Quote Link to comment Share on other sites More sharing options...
plasticbadger Posted February 21, 2011 Share Posted February 21, 2011 The sacrificial anode only works when it is fully submerged so it isnt going to work on a LR. ^^ what he said, but an anode is called a passive galvanic corrosion system, in that all you are doing is providing a metal that is even keener to be involved in the galvanic corrosion process than your aluminium body, as Ross says this only works when all parts are submerged. However some boats do run 'active galvanic protection' by putting a small electrical charge into all the submerged metal work to protect it from being eaten away. This could be replicated on a Landrover, but you would need some way of keeping up with the small current drain of the system. Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 21, 2011 Share Posted February 21, 2011 You can cut out galvanic corrosion by various methods. During my build ive been using neoprene gaskets or washers anywhere steel meets ally. Ive also been using ptfe tape round the threads of bolts that got through the ally bodywork. Anything to stop the small current flowing between the two materials should work. I removed all the steel brackets rivetted on the inside of the ally rear panels, removed any corrosion, applied 3 thick coats of paint between the 2 surfaces, then re-rivetted tham back on. Quote Link to comment Share on other sites More sharing options...
PieEater3142 Posted February 21, 2011 Share Posted February 21, 2011 wow need4speed you have gone to town. On my rebuild at the moment I haven't been quite as meticulous. However I have got a tub of duralac which is supposed to create a barrier between the two different metals and stop the reaction. I am also painting any non ali metal up in hammerite wherever possible to try and reduce the contact. Also Using stainless steel nuts and bolts where I can, just to stop rust showing up. I'm going with diamond white so rust will show up like something crazy. Hinges and missing brackets for my baby arrive this week so it's time to crack out the hammerite paint and then get bolting. Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 21, 2011 Share Posted February 21, 2011 Also Using stainless steel nuts and bolts where I can, just to stop rust showing up... You probably know already, but just in case you dont... Stainless steel reacts with ally even worse than mild steel. That is why i have been careful of wrapping any stainless bolts with ptfe tape where the bolt goes through the ally because wherever stainless is in contact with ally, the galvanic corrosion will be horrendous... Quote Link to comment Share on other sites More sharing options...
PieEater3142 Posted February 22, 2011 Share Posted February 22, 2011 Was planning to use the duralac, it's the modern equivalent of zinc chromate (not allowed it any more due to health and safety I believe - asked for it and got a funny look the other day). Puts a zinc layer between the two metals. But may as well belt and braces and do as you suggest and use ptfe on the bolt threads as well. Can never be sure that the duralac will completely coat... Quote Link to comment Share on other sites More sharing options...
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