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I've bought some 15% from one of the local distributors and it was so weak it would not even stain my shirt if applied straight. 

WeWashWindows wrote:

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I've bought some 15% from one of the local distributors and it was so weak it would not even stain my shirt if applied straight. 

If that supplier is telling people to apply straight solution to the roof, I wonder how that will affect his product liability insurance. If homeowners follow his directions, burning their landscaping will be the least of their worries.

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 I had SH leftover over the winter and I did the finger test and threw an old shirt on the ground an threw some SH on it to test. It still worked as far as bleaching the shirt. I used more of it in the mix.

What is the best way to test the strength of SH ?

I tell you after all these years its still a puzzle any comments would be helpful...

You can do this test yourself. You have to buy a kit that is between $55 & $60 and it will perform about 100 tests.

Most kits that test available SH/chlorine levels will not test the strength that we are looking to test. Most will not even cover the levels in store bought bleach.

Here is an SH test kit that will test up to 150grams/liter of SH or the equivalent to 15% SH. You have to go back to chemistry 101 and use beakers, flasks, reagent chemicals and then do some math. It is used by paper companies to test their SH. They apparently have to have the SH level controlled very closely.

I'm going to order one just play around with it. I'm curious just how fast my SH breaks down. I get it delivered in bulk. My tanks sit outside with no cover over them. They fill up 3 to 4 dark blue 55 gallon drums depending on my needs. I would like to test the strength when it gets there and after a few weeks. I go through between 100 and 200 gallons per week so it never really sits that long, but I may have them fill up a dark blue 5 gallon carboy and just let it sit to see what happens.

Anyhow, if anyone is interested in ordering a kit, they are not that expensive and you don't have to send it out to a lab.

Brian

Markus,
     I have seen a lot of those degradation charts. Believe it or not, quite a few of them have varying results. The Grime Scene has a link posted on there for a similar chart that shows the effective % of SH in three different control groups. They have a refrigerated one, a clear barrel and a dark barrel (if I remember correctly) and they show the effective % after months of sitting. Most people would be surprised how long the SH will really last according to that chart.

I had 35 gallons left over from 2009 that I used in my house wash mixes at the start of this year and they worked great.

The way I do my cleaning, I try to make sure that I have a certain percentage solution hitting the roof or house when I am cleaning.

I try to have 4.5% to 5% active SH mix hitting the roof (40 gallons of 12% SH in 100 gallons of mix equals about 4.5%) and a 1.2% to 1.5% mix hitting the house for a house wash.

Trust me when I tell you that this is WAY over analyzing something that is pretty simple, but I tend to do that. I know how long it should take for my mixes to clean the surface that they are cleaning. If it is taking too long, I add more. If it is cleaning too fast, I increase the water.

I would never spend the time to figure out what % SH I had before I started working. That would be a rediculous waste of time. It is more of a curiosity for me than anything. I read posts everywhere about how fast SH is breaking down. I would like to perform my own study so that I have real world results as to the speed at which MY SH breaks down.

Brian

Pat,
     As I said in the previous post, they don't make the "easy, quick" test strips for checking the concentration that we are talking about. Those strips are made to check much, much lower percentages of available chlorine. Most test strips don't read higher than a 1% available chlorine. That is why you need a test kit similar to what I posted above. Hardly anyone has a need to check for 12% SH and that is why they don't mass produce test kits for them.

Brian