I think I have caused my self a significant problem. I cleaned an AC overflow rust stain using Rust Remover Plus. It did what I have oxalic do which is leave a white haze on the shingles in place of the rust. I did rinse the heck out of it but, no matter at this point. Any idea how to get that off the shingles without destroying them? Thanks for any help.
Can of roof matching spray paint.
Gosh I wanted to say that earlier but didn’t for fear of being laughed out of here and banned for eternity.
Well Rust Remover Plus is primarily oxalic acid. It’s for cleaning rust off concrete and other hard surfaces. Have no idea why Mark would use on roof. Painting or replacing shingles probably only choices. Could try , respraying that area with SH and see if that would neutralize the OX thus lightening the effect, but that’s probably wishful thinking.
F9 is great for rust removal on shingles. Takes about 15 min.
So its calcium oxalate? Maybe apple cider vinegar.
@MDA1775 How big of an area is affected? If it’s reasonably small I’d go with the spray paint idea. If it’s larger then I’d imagine you’ll need to look into some of the other options offered here.
I would imagine the haze would get better as time goes by. Just don’t have any idea how long.
Where to start. I was treating the painted wall above it and I have used it on shingles before without a problem. Looked great when I was done, not when it dried. I thought about the roof paint idea (i did that several years ago when a knucklehead working for me didn’t properly mask a pergola), unfortunately it is a high end property with multi colored shingles so I am not sure it will work. I am going to try the vinegar idea and do some tests with some of the Eacho chem products since it is a calcium issue. Thanks for the replies and suggestions. Happy Mother’s Day to your Mom’s and your wives.
There is a strong version of vinegar available at local grocery stores, its like 9% acidity white pickling vinegar and usuallly only sold in gallon sizes. All others youll see there are likely only 5% acidity.