Stainless Steel and Aluminium?

[side-show-bob]

Hi all

I will be re-building my 67 series 2 landy soon and as i had to cut 90% of the fixings off i will need to replace them. I was going to use A2 Stainless steel fixing but i am sure i read somewhere that stainless and aluminium don't go well together? Can anyone help clear this up for me.

Cheers

Rob

 

[john224]

If you look at some of the landrover sights you will see they sell stainless steel nuts/bolts/screws- sete for these series landrovers,,,

 

[pedrobedro]

Electrolytic reaction or galvanic corrosion, try google. It's something you get between any dissimilar metals.

 

[SwissTony]

Quick look found this

 

[hotrodder]

http://www.bssa.org.uk/topics.php?article=89

 

[voipio]

I saw an interesting situation at work the other day. An antivibration table with stainless steel top had an (approx) 25 x 150 x 150 aluminium plate attached to it with four M6 stainless steel bolts. The plate was in turn the foundation for an extruded aluminium column of about 80mm aquare section. The column was supposed to be vertical but, for some reason, had developed a tilt rather like the leaning tower of Pisa. The reason turned out to be corrosion, produced by a seepage of saline solution between steel and aluminium, which had lifted the ali plate and, in the process, snapped two of the holding bolts! The stainless steel antivibration table looked OK, apart from a slight dullness but the aluminium plate was deeply corroded in several places.

Seawater would have a similar effect.

 

[Endacy]

I've just used stainless on the front of mine. It will react more than the mild steel ones that were on there so I have made plastic spacers to separate the stainless washers from the aluminium, it's the washers that have the greatest surface area and cause most of the problems. I have also earthed everything with wires rather than through the bodywork to keep electrical currents down between parts.

 

[TechnicAl]

Aluminium readily oxidises so it wont be Aluminium in contact with the SS (or whatever) it will be Aluminium Oxide (Al2O3) which is not that reactive.
Mild Steel will sacrifice in preference to Al2O3
Stainless......Im not sure about
However you need to look up Al2O3 and not Aluminium and it will depend on the atmosphere / environment.

 

[graffian]

My lightweight front wing had been bolted on with stainless bolts, the paint covering them was intact and looked fine. I went to take the wing off and when I chipped the paint off there was a corroded mess, when the corrosion was cleaned off the wing had holes the size of the stainless washers. Seen it with floor bolts a few times, never seen it with steel floor bolts.

 

[Dune]

You find this alot on motorbikes. The ally rearsets are often bolted on with SS bolts on to the alloy frame. These can be a bit of a pain to get out after an english summer. Ive found that a good wipe with coppa slip before assembly helps to prevent/reduce the reaction.

 

[syborg]

refering back to my college days it either causes anodic or cathodic corrosion, something to do with the electolitic properties of each metal on each other. its like the tinfoil on dental filllings situation, lol

 

[brookie456]

refering back to my college days it either causes anodic or cathodic corrosion, something to do with the electolitic properties of each metal on each other. its like the tinfoil on dental filllings situation, lol

As syborg pointed out, galvanic reactions between dissimilar metals do give the odd problem, accelerated by the "road salt" used over here. Would rather use a plain mild steel coated (cadmium?) insert and avoid the "galling" between stainless and aluminium-impossible to shift without damage in most circumstances. With normal steel, one rusts, the other rots - gives you at least half a chance.