well water on aluminum

[jgoral76 14]

I have a sweet old aunt and she wants me to pw her aluminum that has what looks like rust on it. This was caused by well water from her sprinkler, the siding is lite blue and alittle oxidizied and may need painting. please advise on the proper way to right this, without breaking her heart.

[Dan Stapleton 14]

You could clean it as a normal wash with as light a chem application as needed and treat the rust areas with oxalic acid. Or you could two step it which should get the rust and oxidation. Test how the paint holds up in small areas first.

[jgoral76 14]

pardon my stupidity but what is 2 step it and how?

[Doug T 19]

Jeff,

"2 step" refers to a process of applying 2 different Ph levels of chemicals and then rinsing. Most common is to apply an acid and then an alkaline and then rinse. The acid and alkaline react on the surface to give a "better" cleaning action.

Doug

[PressurePros 248]

This is a good test bed to try the technique. That blue siding is always badly oxidized.

[PLD 14]

Search for my previous thread on well water. I have flash rusted an entire side of a house in 30 seconds with iron rich well water. Oxalic and an x-jet saved my behind.

[jgoral76 14]

Ok a few ?'s what type of acid( i assume oxalic ) should be used and what alkaline would be recommened also what can be xpected, a bright blue sidingjust looking to see what type of results i can be xpecting. do i need hot water? since the well water did this i assume i have to tote water?

I searched for that prev thread and unlessi did something wrong i can't find it.

[Dan Stapleton 14]

Some people use Hydroflouric. It's ly stuff. I'm no expert but Phosphoric and Oxalic will work. No rinse then spray on housewash (alkaline). Be careful with windows.