Word to the wise - Aluminum

[Meph]

*EDIT This actaully applys to Tin not Aluminum, Aluminum is the opposit, and will be coroded by the steel. Theorticaly, a tin modification would cause the steel to rust out. Has been fixed to read correctly


Hey,

Ive been reading through some threads about front and rear air dams, underbody pans ext. Some of you are saying you'd like to make them out of aluminum instead of sheetmatel, but beware, steen is more reactive that aluminum, and by putting a sheet of aluminum ontop of steel it will cause the Aluminum to oxidise at an accelerated rate!

This info came to me from a Science Prof. who was into cars, and use to pop rivit aluminum onto steel for cheap/fast/easy repairs. Within a year the entire area around the aluminum pannel would rust away.

It dosnt make a ton of sence unless you study metal and chemestry for a while, so just be aware. If you still plan to do it, at the very leaving rubberize the metals surfaces before you do.

Good Luck

[Ryland]

that is why it's best to glue it, not screw it together, and if you are installing it under your vehicle make sure you have good thick under coating, if you do pop rivet it, you can find plastic pop rivets for plastic bumpers.

[tasdrouille]

You are referring to galvanic corrosion, which is not a huge problem between aluminium and steel. And in any way, the aluminium will be the metal corroding faster, not the steel, as it's the least noble of the two.

You should always apply/reapply a good protective layer over metals anyway to prevent corrosion from happenning.

[Meph]

hum, maybe it was Tin he was riviting on as that is ranked higher, must have got it confused. The moral of the story is, dont try to be a smart ass. :P

[Duffman]

Originally Posted by tasdrouille

You are referring to galvanic corrosion, which is not a huge problem between aluminium and steel. And in any way, the aluminium will be the metal corroding faster, not the steel, as it's the least noble of the two.

You should always apply/reapply a good protective layer over metals anyway to prevent corrosion from happenning.

+1
Aluminum is the one which will corrode and protect the steel.

[trebuchet03]

Use a penny as a washer They're still zinc cores right? Or anodize the Al


Sheet aluminum is pretty damn expensive compared to many lightweight alternatives

[Meph]

On a side note, is there a way to make sacraficial zinc anodes on steel body cars?

[tasdrouille]

Oh you sure can make them, but they won't work much unless you immerse your car in salt water.

Personally, I like Loctite Cold Galvanizing Compound

[Duffman]

Originally Posted by tasdrouille

Oh you sure can make them, but they won't work much unless you immerse your car in salt water.

Personally, I like Loctite Cold Galvanizing Compound

Good find!
All the other sprayable galvanizing products I have seen before always say, not to be painted over.

[brucepick]

Originally Posted by Duffman

Good find!
All the other sprayable galvanizing products I have seen before always say, not to be painted over.

Dunno if they say that because most metal primers don't work worth a darn on galvanized surfaces - or for some other reason (liability re.???)

Anyway, I found some acrylic-based primer intended for aluminum and galvanized surfaces. Not too expensive really. I used it on stainless trim on my car with excellent results - about two years later and the topcoat is still there, with the primer hidden below. Probably available in your local stores. It's white.