aluminum siding corrosion

[jjones2]

has anyone seen blistering on aluminums siding like this? it seems to be localized to the north wall which happens to have dense shrubs. chemical spray treatment possibly? galvanized nails? Any ideas?

Thanks, John

[Joe Funderburk, CMI]

Looks like a paint defect more than corrosion. How much was there?

[jjones2]

quite a bit, it looks like what happens to your car from the rust causing the paint to bubble.

[jjones2]

here is another shot

[rdimmerling]

I can't really tell from the photo but did it look like it was recently painted (not the orginal factory coating)?

[iniquette]

To me it looks like the owner tried to touch up some spots on the siding and the touch up stuff blistered.

[Jeffery L. Haynes]

owner probably used latex paint......which will do exactly what is shown in your pictures (because of ammonia in the latex)...............aluminum siding can be painted but it must have a oil based primer first.....other wise one is wasting their time.

regards

Jeff

[Kenton H. Shepard, CMI]

If it's a paint issue, it will be a failure of the bond and may feel hollow.
If it's corrosion, popping a little section should show corrosion.

Aluminum doesn't really corrode, but there are similar alloys that will. Are you sure this wasn't a steel-core product coated with aluminum?

[Larry D. Kage]

Originally Posted by kshepard

Aluminum doesn't really corrode, but there are similar alloys that will.

I think you mean it doesn't rust, which is for iron and steel corrosion, but aluminum does corrode. I believe the corrosion is aluminum oxide which protects the aluminum some from further corrosion, as I understand it.

[Kenton H. Shepard, CMI]

Aluminum is a high-energy metal, meaning it takes a lot of energy to mine, refine, combine and manufacture it. This also means that it should corrode fairly easily, since high-energy metals naturally break down until they reach their lowest energy state, which is usually an oxide, as you said, Larry. Oxides are the raw materials used to manufacture aluminum and other metals. They're what's taken out of the ground.

I've asked about aluminum corrosion but never really gotten a satisfactory answer. Anyway... I sure would like to know the real answer to this one.