Hey Ken,..hanks for posting,.that reassures my experiences with F-13.
In the warmer temps (75 and Sunny) the PP can be cut in half, on typical gutter streaks,..and is actually the better choice,..especially on gutters where the paint is failing. If it is really warm like 85+ it can be cut into thirds. With that said,..we try and get our house washing done in the morning hours before the heat sets in on the hot Summer days.
*Gutter streaks vary greatly in degree of "toughness",..after almost 20 years I can look at them and tell if they're gonna be a B***h or not. I don't know if inferior products are more prone to the bad ones or not, but I hate seeing the ones that are gonna be tough,..You have to arrange your schedule around them in accordance with the weather. Last year we did a few that I told the customer,.."We'll be here when the temps start getting into the 90's, Ha,Ha,..
*It was very cool yesterday, and the job we were on was one with bad gutter streaks,..I actually forgot about them because I forgot to note it when I looked at the work about 3 weeks ago,...PP wouldn't touch them ,.even when scrubbed with Magic Eraser,..which will in many times make them doable,..and I HATE telling a customer we couldn't get the gutters clean,.. especially considering if I chose a better day they would have,..so I was contemplating finishing the house wash and coming back to do the gutters,..PITA,...
So we used an unconventional cleaner and added it to the Magic Eraser,..and the very tough gutter streaks wiped right off and didn't damage the paint at all,..we kind of laughed at how well it worked,..and left the customer with bright white gutters. And is definitely a new "tool" in the gutter cleaning kit,..especially in the cool periods. It could have been sprayed but we chose not to in this test case,Ha,Ha,..
*Although the results were professional the product was not,..it didn't hurt anything, (Probably less damaging than the PP),... and we will be doing it again if the need arises. It is a two step process.
**I am not gonna disclose this to the general forum, because too many un-professionals read here,..in reality I think if you use your imagination you will figure it out,Ha,Ha,..
***I will tell anyone who wants to know through PM,..and if I'm familiar with you.
Jeff