Hi Guys, im back on this one and yes Avo could be right (Acid) i talked to a guy who had been using a wfp system for years but got out of window cleaning and is now back doing carpentry work, he reckons using pure water used to affect his skin and cause damage to customers window frames,soffit and fascia,UPVC doors, and paintwork, and eventually just became afraid of using his system, he is gone from window cleaning over 4 years now so maybe the technology has changed today, at the time he went to a local company who do water testing and they told him that when water is purified it can turn it into an acidic cleaning solution which would be capable of causing damage to surfaces, he did say that after six months his skin problems cleared up, again guys i have no knowledge or experience of working with wfp systems so if there was problems in the past im sure with todays technology they would have them ironed out, at that time he said the water testing company tested the water from his system and it was reading 5 on the ph scale which would of made it very acidic, he also said that it was probably his own fault because he never got to grips with using and trying out different types of resins so decided that he had enough, so as i say i dont know how these systems work but maybe if the water is to pure it might also be more acidic, best to check this out with experts on the subject.
The plot thickens...........................
The thing is on paper pure water is supposed to be 7 ph, which would make it neutral and neither acidic or alkali.
However I do understand that perhaps it doesn't always come out at 7 ph.
I've never tested mine to be honest so couldn't tell you if it is 7 ph or above or below.
Besides that I still believe there is a possibility that there are quality problems with the door manufacturing process unless a harsh cleaning chemical has been used previously on the door.
Because if the pure water we use was that acidic it would be stripping paint off of wooden window frames, and in my experience that just does not happen.