IndyExterior
New member
I and a couple of others have posted about SH possibly damaging copper flashing and roofs etc. We have a lot of homes around here with bay window copper roofs and we still find older homes with copper gutters and flashing. I never seemed to get a clear yes or no. We used what may have been extreme caution around them, which means time. So I got some solid copper flashing and did my own test. Not very scientific but just an FYI of what I found. They all were cut from the same piece and started out looking like B.
Piece A was immersed in 12.5% for 10 minutes and allowed to air dry with no rinse.
Piece B was immersed in 12.5% for 24 hours and rinsed completely immediately.
Piece C was immersed in roof mix 65% water and 35% of 12.5% SH for 10 minutes and air dry
As you can see it only appears to discolor and form copper oxide when allowed to air dry. So those of us that do not rinse may want to consider rinsing when copper is present. I know no one is going to immerse copper in 12.5% but wanted to create an extreme example.
It also occurred to me that someone mentioned that they thought allowing chemical pumps to dry out caused more damage than keeping the chemical in them. This shows there may be something to that also.
Piece A was immersed in 12.5% for 10 minutes and allowed to air dry with no rinse.
Piece B was immersed in 12.5% for 24 hours and rinsed completely immediately.
Piece C was immersed in roof mix 65% water and 35% of 12.5% SH for 10 minutes and air dry
As you can see it only appears to discolor and form copper oxide when allowed to air dry. So those of us that do not rinse may want to consider rinsing when copper is present. I know no one is going to immerse copper in 12.5% but wanted to create an extreme example.
It also occurred to me that someone mentioned that they thought allowing chemical pumps to dry out caused more damage than keeping the chemical in them. This shows there may be something to that also.
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