V8_Disco
New Member
if you mean alluminium and steel, when put together they tend to turn to white powder instead of rusting?
i was going to get some nuts and bolts to re attach the front bumper with and some flange nuts for the exhaust mani. if they just turn to white powder then that isn't a problem i just don't want the bumper mounts to rust like mad
when "mild" steel and "stainless" are used together, then corrosion will cross the molecular boundary from the "mild" steel to the "stainless", causing the "stainless" to corrode - to a greater or lesser extent depending on what the two varieties of steel are. The "stainless" will, however corrode at a much reduced rate.
It is only Aluminium Alloy which turns to white powder (Al Oxide), in the same method that iron returns to its Natural red powder (Fe Oxide).
The only way to reduce this is to
remove oxygen from the surfaces ( a barrier)
stop an electrolyte from being present ( a barrier).
It is only Aluminium Alloy which turns to white powder (Al Oxide), in the same method that iron returns to its Natural red powder (Fe Oxide).
The only way to reduce this is to
remove oxygen from the surfaces ( a barrier)
stop an electrolyte from being present ( a barrier).
so i shouldnt use them on the landy? i take it that the exhaust mani and the chassis are mild steel? if i used them to mount the front bumper would hammerite act as a barrier? the only reason i'm using stainless is that the landy place round here wants 1.45 per nut for the mani and i'm thinking thats a but much just for some nuts and i can get stainless cheeper then that so i thought i'd order them for the bumper at the same time
Use stainless on normal bodywork, with a barrier (paint/waxoil/schultz/oil/grease etc) but on a manifold use brass nuts and plenty of Coppergrease or Turmopast TAS WT (page 8)
Last edited:
on a Manifold, Turmopast is better than Coppergrease as it is rated to 1400C
