S2C Forum Archives
Main Section => Welcome to our virtual Pub Meeting ... => Topic started by: Ken on June 26, 2023, 11:41:49 AM
-
A new problem to me though not to anyone with long term involvement with Land Rover. How to deal with galvanic corrosion.
Having removed what’s left of the steel I have aluminium with heavy white deposits of galvanic corrosion. The obvious next move is to clean it as much as possible and having wire brushed it most has come away. The surface is however pitted with white powder in the pitting. So what next ? Is that good enough, if painted over will that check it or is there something else that needs doing. Any suggestions will be appreciated.
-
I faced this last week on the rear of my tub Ken. As you have, I wire brushed most of it away, added some sanding, then etch primed and top coated. It looks great, but I don't know whether I should have treated as well.
-
My turn to nit pick at pictures... James - isn't your antiluce upside down?
-
Ha! Probably. I'm weeks away from finishing the tailgate, so just bunged them on. Will be right when I get there I promise...
-
That's good - otherwise gravity would take over and your nicely rebuilt tailgate might make a bid for freedom!
-
The late Ken Wheelright (Series One restorer supreme) told me that he used vinegar on his motors to treat the white corrosion.
-
If my memory serves me correctly there are 2 versions of that antiluce and reinforcing.
One like James's where the antiluce is separate and is bolted through the tub
Th other is like mine where the antiluce is welded to the reinforcing - mine cant be fitted upside down
Peter
-
I am quite fussy with white rust pitting in aluminium.
Having rotary wirebrushed the surface vigorously, there is still pitting and those pits are deeper than you think.
I sit with my Dremel and a pointed router bit, and dig them out. It takes ages but as I said, much more comes out than expected and sometimes the pit actually extends all the way through, but is hidden by paint.
When all the pits are shiny rather than dull, I then paint with phosphoric acid and leave to dry overnight. Any holes are filled with JB Weld and sanded.
Then I think about painting......
-
A mild acid such a vinegar should get most of the white powdery deposits out of the corrosion. After that filler and paint I guess. On thicker more structural stuff you’d want to weld up the pitting but that’s easier said than done with land rover panels.
-
Thanks for the advice everyone, JB weld is on the way, I have some phosphoric acid so will use that.
-
Hi,
Dare I ask if this galvanic problem could have anything to do with POSITIVE EARTH?
Probably best if I don't ask, and just get my coat!
602
-
I think you're right about positive earth causing more corrosion. I seem to remember that early vehicles were negative earth then it was changed to positive then back to negative with the introduction of alternators although early alternators were positive earth, mainly on Hillman cars if I remember right,
-
My negative earth later Land Rovers suffer from it badly.
My Series Ones, very little.
Albeit that it might have something to do with the type of bonding, and amount of paint (if any) between the metals.
-
I can remember the "fur" on the earth terminal of positive earth cars which prevented starting and as a "knowledgeable (?)" youngster I was often called to sort it out. I don't remember seeing such a build up on negative earth vehicles.
-
I can remember the "fur" on the earth terminal of positive earth cars which prevented starting and as a "knowledgeable (?)" youngster I was often called to sort it out. I don't remember seeing such a build up on negative earth vehicles.
Still get it, but limited to the battery connections, hot water wash usually gets rid of it followed by a good wash down.
-
Was only ever a problem for me on a positive earth truck, near to where the rear electrics were earthed, but that could just be a coincidence.
-
I was designing at the Austin, Longbridge from 74 to 79. I guess it would be around 76 or 77 that the lab in Cowley conducted tests on the corrosion effect of negative versus positive. They were more than surprised that there was a difference and I can still recall how surprised.
-
I was designing at the Austin, Longbridge from 74 to 79.
Do we blame you for the Austin Allergic?
-
Not me, I always read it as Rustin Allegro. I could tell you what I did but it would involve a lengthy explanation!