Black streaks?

[JeffW 14]

I have been washing houses for ten years now,.....yet I am still uncertain what causes the perfectly spaced black streaks on rain gutters.Could someone enlighten me.I have seen this on gutters that are only a year old or less.I can clean them easily(as long as it's warm enough),... but would still like to know what causes them.Thanks for any and all positive responses.

[Beth n Rod 1,279]

There has been a great deal of grey matter churning in this one!

Ryan, your theory is related to the electrostatic bonding. I have heard it explained somewhere at a previous convention before while trying to keep more than one conversation going (you know') and caught the main parts of it and stored it in my brain next to the category "gutters suck because I hate working on ladders to clean them!" and just remembered other parts of the conversation that referred to gutter zap and gutter brite as cleaners suggested to do the job.

But since there is an electromagnetic field associated with each homes wiring, this along with the natural phenomenon of acid rain..........who knows....I need to get some more caffeine.

You guys let me know when you've figured it out. :lol:

Rod~

[Atlantic Power Washing 14]

Have you ever polished aluminum before? then you know when aluminum breaks down it turns black. Anywhere there is aluminum you will find black steaks. Crown molding under windows where they used aluminum flashing on top, the aluminum breaks down and bleeds on to the painted wood below. Water flowing down aluminum couses fricktion that breaks down the aluminum and then you have a black streak. When it rains the outside of the gutter get wet too and the water puddles up on the top ledge of the gutter (it actually goes behind the pores of the paint and breaks down the aluminum) and then rolls down the front side of the gutter. So the black streaks are actually the broken down aluminum particals itself.

[tunatussle 14]

I get black streaks on the surface of my fiberglass boat interior that look the same as the zebra lines on gutters. I think it is the result of acid rain from our Canadian brothers coal fired energy plants coming down wiht the weather fronts. The rain water runs down the vinyl coated coaming boards and drops onto the bulkheads where it eventually dries leaving streaks. I usually get them off with Softscrub and a soft brush.

[PLD 14]

Have you ever polished aluminum before? then you know when aluminum breaks down it turns black. Anywhere there is aluminum you will find black steaks. Crown molding under windows where they used aluminum flashing on top, the aluminum breaks down and bleeds on to the painted wood below. Water flowing down aluminum couses fricktion that breaks down the aluminum and then you have a black streak. When it rains the outside of the gutter get wet too and the water puddles up on the top ledge of the gutter (it actually goes behind the pores of the paint and breaks down the aluminum) and then rolls down the front side of the gutter. So the black streaks are actually the broken down aluminum particals itself.

Finely divided aluminum does appear grey\black. Polishing creates finely divided aluminum. Aluminum Oxide on the other hand is clear. And it is one of the hardest substances on the planet. That's why it is used for sandpaper.

Ever wonder why aluminum cans do not rust? Or teh insides of aluminum gutters? Actually they do. A very thin layer of clear aluminum oxide forms and prevents further decomposition.

This is a great thread. Obviously, painted aluminum appears to streak regardless of proximity to oils. Atmospheric dirt seems plausible, but gutters and downspouts should be just as suceptible. Obviously they are not as succeptible. Overflows do increase the effect, but blackness is not directly coupled to overflow as some overflows do nothing, while others make very visible black patches. And gutter bottom spouts which see the most water have the least streaking. Yet, the top of the downspouts which should not see much water streak badly and in clear flowing patterns.

All that said, I'm not sure what compounds form the streak, but I do believe ES bonding keeps it there. And there are unknown situational circumstances which increase or decrease the streaking significantly.

Philip

[MMI Enterprises 289]

Read this whole thread through and through and am dismayed that no one really came up with the answer as to where black streaks on guttes come from... Well I finally figured out what causes streaked gutters....

It's bird toe jamm... :)

[jakobe 14]

I encountered some of the worst "streaky" gutters today

it was in a narrow corridor along a roofline that meets a porch

it has this little tiny alley full of bushes

the house was brick and the only heavy black streaks on gutters were in the damp corridor

on the gutters there is an aluminum or tin piece of flashing that sticks up near the corner

no streaks under it..?

but streak just a few inches from it.

it is so strange that these streaks are only on this one section of gutter.

Im going back tom to take a second look and snap a few pics.

I cleaned with a shc,based housewash mixture first and killed all the mold

then hit it with a butyl cleaner and let it dwell

then reached up there and tried to scrub by hand..nothing

then hit it with chemical again and attacked it with a turbo nozzle..no change

it was a 50% improvement

customer not real thrilled, neither was I

I have always had a problem with gutters

this was the worst section I have ever seen

My suggestion was to have the builder paint the gutters

considering this house is only 2 years old.

suggestions?

explanations?

.......solutions?

[Kory 14]

Airplanes! Thats my story and im sticking to it. Jet fuel that burns and falls to the ground. Gutters are worse the closer to flight paths.

[814jeffw 71]

Epoxy coated gutters is what we need. I always blamed the paint. But then again they get on other things than just gutters. RV's and boats come to mind.

Jeff