How to remove these stains

[Rustyiron]

TSP mixture. It's a hardware store item.

TSP - Trisodium Phosphate: The Painter's Degreasing Choice

A quality of a paint job depends on using a powerful degreaser, like TSP Trisodium Phosphate, to clean and etch the surface.

www.house-painting-info.com

There are other "recipes" for cleaning only. Just search TSP mixture for aluminum siding.

 

[Alan46]

I’m a 40 year retired painting contractor. What I would do is just mix a very small amount of bleach and water ( 4 water 1 bleach) try that on the lowest part of gutter. Just use rubber gloves and a rag, if it’s mildew it will disappear in a few minutes!

If you have any questions p m me!

 

[Williy]

I would try the 9% vinegar mixed with some water
as vinegar kills mildew/mold and its a great cleaner

willy

 

[Thomas]

I use bleach mix with dish soap works well.

 

[LS Tractor Owner]

Another product that will work is "RV black streak remover". Works great on aluminum and painted metal.

 

[Spike56]

I use bleach mix with dish soap works well.

Thomas, No doubt the bleach works. I used that initially. In my case, the bleach slightly changed the color shade and required me to re-paint. Guess it depends on several factors (color for example). Mine were an off white that matched the facia boards and after wiping the gutters using bleach, I could tell enough difference that it looked odd to my eye. At least for me, I would not use bleach again on a painted surface. So, not against you on this, just a word of caution here.

 

[tstex]

Ok, I mixed 1/4 12.5% bleach to 3/4 water w 1 tablespoon of liquid soap. I agitated and applied w a paint brush and moved brush back and forth 3-4 times. It barely lightened it. Then came back dish scrub pad, dipped in solution and scrubbed back and forth. Then hosed down w the strongest pressure setting from hose bib.

The first pic is what it looks like now; second pic I have done nothing. To me, the first pic is a slight improvement, but not much.

Any suggestions since i have all the supplies out? Should i strengthen the bleach %? Skip the soap? Anything else?

Thanks

 

[Alan46]

“I’m a 40 year retired painting contractor. What I would do is just mix a very small amount of bleach and water ( 4 water 1 bleach) try that on the lowest part of gutter. Just use rubber gloves and a rag, if it’s mildew it will disappear in a few minutes!”

I would say if the above didn’t work, it’s not mildew!
Maybe call a gutter company and ask for a recommendation! Sorry that’s the best I can offer!

 

[tstex]

“I’m a 40 year retired painting contractor. What I would do is just mix a very small amount of bleach and water ( 4 water 1 bleach) try that on the lowest part of gutter. Just use rubber gloves and a rag, if it’s mildew it will disappear in a few minutes!”

I would say if the above didn’t work, it’s not mildew!
Maybe call a gutter company and ask for a recommendation! Sorry that’s the best I can offer!

Thank you Alan - First, I corrected my mixtures above...used 25% bleach to 75% water, 1 TBSpoon of liquid soap [before i said bleach but corrected].

Would it be best to apply w sun on it or not? It's almost perfect weather here at 68 degrees and RH of 35%...I can wait later if no sun, but it is pretty windy too...10-15MPH...Thanks again.

 

[Alan46]

I would try a small easy to reach section in the shade first, before doing too much just to see if it works! Keep me posted! If it does work and you spray with a pump up garden sprayer make sure you wet down any plants & things you don’t want to bleach also wear eye protection!