What chemical cleaner for white residue on glass?

[Chris34]

Got a job that has an exposed metal lintel above black framed bi-folds. The metal has become corroded and chalky white residue trickle lines are all over the frames and the glass. The above is a balcony so the lintel is sheltered from rain but previous window cleaning must have resulted in all the white residue. It's quite thick, it's not like the leaded residue marks you get, it's more chalky.

Just wondering what's best to use on it if anyone has any experience with it? Would something like Viakal work on it? The metal is corroded and is showing signs of rust.

If I can get it clean then future cleans I'd avoid the lintel and clean the rest of it, it is pretty bad though so needs a fair bit of work to get it right.

Just to add, I've tried barkeepers cream that usually removes the leaded type residue, it didn't make a difference on this stuff.

 

[RickyG]

Sounds like zinc oxide/ white rust try a bit of vinegar or oxalyic acid on the glass & a good splash over the lintle should calm it down

 

[AW Services]

Got a job that has an exposed metal lintel above black framed bi-folds. The metal has become corroded and chalky white residue trickle lines are all over the frames and the glass. The above is a balcony so the lintel is sheltered from rain but previous window cleaning must have resulted in all the white residue. It's quite thick, it's not like the leaded residue marks you get, it's more chalky.

Just wondering what's best to use on it if anyone has any experience with it? Would something like Viakal work on it? The metal is corroded and is showing signs of rust.

If I can get it clean then future cleans I'd avoid the lintel and clean the rest of it, it is pretty bad though so needs a fair bit of work to get it right.

Just to add, I've tried barkeepers cream that usually removes the leaded type residue, it didn't make a difference on this stuff.

Concentrate White vinegar is my go to chemical. Food standard and cleans well.
Just wear gloves as it will find any cuts and you'll be dancing like James brown