So had two high school friends call and ask to come look at a couple projects. One I found out is limestone block building with algae and some resistant tough grey blackish stains and other is weird colored brick I don’t think I’ve ever seen before. From reading lots of back n forth on if sh mix will do anything on limestone if not an acid? And I’d say sh if it didn’t look like it has paint on it not sure except to try a small mix on an area? Thoughts?
What’s that last picture of? Looks like concrete.
You should be fine using SH on that first brick. Many use SH on limestone too. The second picture will take multiple applications.
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Looks like corrugated aluminum like on a overhang of a eave
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Yeah, you’re right. It does. SH should take care of it.
Ya didn’t mean to put it in there but ya it’s an aluminum awning. Wasn’t sure if an aluminum cleaner would be route for it or sh would work for it. Never saw brick like that so wasn’t sure if sh would discolor. Thanks for help guys!
When in doubt always do a test spot in an inconspicuous area.
Done a test spot on the limestone building. It cleaned up but not exactly how I thought. That was 5% mix and decent pressure. Stronger mix??image|375x500
Pic doesnt work for me.
It’s the bottom right block
Those spots on the aluminum look like corrosion pitting to me. You’ve worked with aluminum a lot more than I have, am I off base here? And if it is pitting, is there anything that can actually be done about it?
i havent done much aluminum work. I was gonna try aluminum cleaner after sh mix. More concerned on how to really get that limestone block to flash white again.
