Black metal guttering with white build up

[DeLaCruz]

Something on a clean I have to do I haven’t seen before looks like a heavy white stain on the black metal guttering - gonna be using the usual virosol mix but wondered if others had seen this kinda staining ? When I glanced okay it my gut feeling was this could be a substance that degreaser won’t work on 

 

[Deleted member 7446]

Something on a clean I have to do I haven’t seen before looks like a heavy white stain on the black metal guttering - gonna be using the usual virosol mix but wondered if others had seen this kinda staining ? When I glanced okay it my gut feeling was this could be a substance that degreaser won’t work on 

View attachment 24248

View attachment 24249

Would that be salt deposits or Galvanic corrosion from dissimilar metals for example cast iron gutter and galvanised nuts and bolts if so you may struggle to clear the staining 

 

[DeLaCruz]

Would that be salt deposits or Galvanic corrosion from dissimilar metals for example cast iron gutter and galvanised nuts and bolts if so you may struggle to clear the staining 

Doesn’t feel like it would be salt as I clean plenty of black plastic gutter nearby with no salt deposits - gut tells me it’s something to do with the metals reaction to the surrounding environment 

 

[Part Timer]

All I do with jobs like these is say I don't know how well it will clean, manage customers expectations. Then if it cleans up well job done, if it doesn't you've covered yourself.