[swhitevt]

Hi folks,

I'm new to the list, and I'm interested in getting an Insight. One of the questions I haven't seen answered in looking at old posts is about the durability of the Insight's aluminum construction.

I have heard comments (from my local Honda dealer, as well as a comment within a post on this forum) that the aluminum won't deteriorate like a steel-constructed car. I wonder, though, looking at my aluminum cookware: there is definitely corrosion and pitting in the surfaces of the older items. These pots are subjected to temperatures and pressures that most parts of a car wouldn't be subjected to (pressure canners), but it does tell me that aluminum can corrode.

I drive about 10,000 mi/yr, so here in Vermont with a steel-based car, rust ruins the vehicle long before the engine wears out.

Does anyone know what kind of wear and corrosion (if any) to expect with aluminum on salted roads?

Thanks!

Sara

 

[Aaron Cake]

Southwestern Ontario (where London is located) is known locally as the "rust belt". We severely oversalt the roads, for some unknown reason. After about two years on the road, most cars are starting to show rust underneath (mostly on fasteners and components near exhaust heat). I've driven my Insight through two winters, and not made any effort to clean the underside. I honestly can't find corrosion anywhere, except some surface rust on some of the exposed steel components. Since all the fasteners are coated to prevent reaction with the aluminium, they aren't showing any signs of corrosion either. That said, I have noticed some corrosion between the engine and transmission, and other seams in that area that seem to trap moisture. But it doesn't worry me.

One of the great things about aluminium (and metals like stainless steel) is that they form a thin oxide layer over any exposed surfaces, thus going a long way to preventing further corrosion.

Cookware is also subjected to amazingly harsh conditions. Many of the foods we eat are suprisingly hostile chemically. Tomatos are very reactive with aluminium (ever noticed how tomato sauce dissolves aluminium foil?).

 

[Tim Maddux]

A lot of the pitting in aluminum cookware comes from the oxide layer being constantly removed through use and/or cleaning in the dishwasher. That in turn makes it much easier for food or salt (or dishwasher detergent) to repeatedly attack the underlying metal.

My Insight spent 2 years on New England salted roads and 2 years before that driving daily through Southern California sea spray. I saw no signs of corrosion or pitting.

 

[b1shmu63]

Honda also makes the NSX (120 thousand dillars) out of aluminum. I saw one at the Accura dealer. It was old enough that the leather seats were showing their age, but the body looked new. Come to think of it my brothers 22 year old VW has plenty of rust , but the front and rear bumpers are made of extruded aluminum and they still look new. Same goes for the aluminum wheels on my 14 year old CRX, which have some surface chalking corrosion but nothing significant. A few of the parts on the Insight engine and tranny are Magnesium castings which will certainly corrode and at least one small part is cast iron. Fortunately these are relatively thick pieces.

The old cookwear was cast and castings have voids that encourage corrosion.

 

[Rick]

Alluminum will last much longer. The way I understand it alluminum over time exposed to air will form an alluminum oxide coating. This shell is ever harder than the alluminum underneath. This will tend to chip off some if struck, but in general is way better off than steel which forms iron oxide (rust) which is water soluable. Rust then tends to flake off also, alluminum oxide holds stronger to itself than unoxidized alluminum.

In short, yeah it will last much longer than steel.

 

[b1shmu63]

Ruby, Sapphire, and corrundum are jem stones composed principally of Aluminum oxide, and are second only to diamond in hardness. Annodizing aluminum produces a thin transparent layer of corrundum on the surface of the aluminum. Any problems with aluminum will generally occur as the result of elecrtical contact with other metals in the presence of an electrolyte. That is why the steel bolts are treated.

What a bizare world this would be if all cars were aluminum. The roads would be filled with old cars! :roll: