Anodized vs. Powdercoated

First off, I know this has been discussed in a few other threads, but I figured it was a good idea to consolidate the topic to one thread.

So I have been looking into the subframe braces from AVO and Cusco. AVO claims that their steel braces undergo a "Salt treatment" then are powdercoated.

Cusco's braces are made from anodized aluminum.

The topic up for discussion is: Which treatment do you feel would hold up better to the elements, salty roads and long winters of the Northeast or similar areas?

I vote neither.

I would think that the anodized aluminum would pit in the weather. It may not look horrible because it would likely maintain its colour .... but would take a beating that could not be fixed.

The AVO might take some of that same pounding but you could "fix" it.If you had an issue after a winter or 2 you could simply have the brace blasted and repainted.

Yeah, that's kinda the direction I was leaning, but was curious to see others opinions.

Thanks Greg.

Yeah, that's kinda the direction I was leaning, but was curious to see others opinions.

 

Thanks Greg.

It doesn't matter what everybody else has to say.

I know all.

If the AVO braces are stainless steel, then they will last longer than the rest of your car

Are you sure they are SS ?

My mistake, they are just steel, not stainless.

Latest and greatest from the R&D group is our underbody suspension brace for the 05+ Legacy, 08+ WRX, and 09+ Forester. Constructed from strong, yet light steel, it offers a rigidity edge over other underbody braces constructed from aluminum. The additional strength also allows for us to make adequete space for fitting, or working on, your downpipe.

Interesting description, what do they do to steel to make it "light" as opposed to "heavy".

Steel has a density of 7.85 , not much you can do to it to change that

Seriously though, I doubt that there is any noticeable difference in the strength of them, it will come down to personal preference and price.

I have both the cusco swaybars and the cusco braces.

The swaybars are steel and needed repainting after just two years, the braces are aluminum and the coatings are still ok after one year.

If they do need painting again, it's not a big deal to do it though.

Interesting description, what do they do to steel to make it "light" as opposed to "heavy".

 

Steel has a density of 7.85 , not much you can do to it to change that

That is correct. But, it is possible to use a combination of a harder steel and processes that leave a compressive residual stress on the surface of the part, like shot peening or roller burnishing, which will allow one to make the part with less material - thus "lighter".

I have no idea if this is the "light" steel they are using or not though

For the ultimate in protection and looks, you could clear coat your anodized aluminum pieces, which would give an additional surface to wear or chip away before there is cosmetic damage to the part underneath (please cue the plastic slip cover jokes).

On another note, one of the beneficial things about aluminum corrosion is that the oxide formed has nearly the same volume as the underlying alloy (Pillings-Bedworth ratio of near unity), which can allow it to stay intact and provide protection to the metal underneath, as opposed to rust (which is also known as corrosion) which has a different ratio and does not maintain its integrity, as it expands when formed and displaces itself (think of the bubbling of the quarter panel of most any GM truck without galvanized panels).

Of course you could find a car dealer more than happy to spray the undersurface of your car with a protective coating that they would like you to believe is "rust-proofing".

As far as "regular" steel and stainless steel, most tubular alloy structural steels in use today (at least in the aerospace industry) are highly corrosion resistant. Stainless steel, for all of its anti-corrosion properties, though stronger than aluminum, is not in league with the high-strength alloy steels, and IMO is not the ideal steel for this application. It would be nice to know the actual composition of steel used for the AVO brace and the type of welding as well, ideally 4340 chrome moly or better, TIG welded, for high strength (including fatigue strength), corrosion resistance and affordability.

I would opt for the latter construct (painted high strength alloy steel), as the minimal increased weight from the use of steel is offset by the superior strength, which in this application should be paramount. When calculating the weight difference between the steel and aluminum, note that it is located is well below the cars center of gravity.

As far as plain old appearance, the bottom line is that unless you regularly display the under surface of your car with a mirror (after you have spent hours hand cleaning everything), no one can see the difference between powder coating and a can of rustoleum.

For the ultimate in protection and looks, you could clear coat your anodized aluminum pieces, which would give an additional surface to wear or chip away before there is cosmetic damage to the part underneath (please cue the plastic slip cover jokes).

 

On another note, one of the beneficial things about aluminum corrosion is that the oxide formed has nearly the same volume as the underlying alloy (Pillings-Bedworth ratio of near unity), which can allow it to stay intact and provide protection to the metal underneath, as opposed to rust (which is also known as corrosion) which has a different ratio and does not maintain its integrity, as it expands when formed and displaces itself (think of the bubbling of the quarter panel of most any GM truck without galvanized panels).

 

Of course you could find a car dealer more than happy to spray the undersurface of your car with a protective coating that they would like you to believe is "rust-proofing".

 

As far as "regular" steel and stainless steel, most tubular alloy structural steels in use today (at least in the aerospace industry) are highly corrosion resistant. Stainless steel, for all of its anti-corrosion properties, though stronger than aluminum, is not in league with the high-strength alloy steels, and IMO is not the ideal steel for this application. It would be nice to know the actual composition of steel used for the AVO brace and the type of welding as well, ideally 4340 chrome moly or better, TIG welded, for high strength (including fatigue strength), corrosion resistance and affordability.

 

I would opt for the latter construct (painted high strength alloy steel), as the minimal increased weight from the use of steel is offset by the superior strength, which in this application should be paramount. When calculating the weight difference between the steel and aluminum, note that it is located is well below the cars center of gravity.

 

As far as plain old appearance, the bottom line is that unless you regularly display the under surface of your car with a mirror (after you have spent hours hand cleaning everything), no one can see the difference between powder coating and a can of rustoleum.

Great post! Thanks for the info.