[kevinc]

 :)hi i need to understand the difference between hydrophilic and hydrophobic glass as i can't get my head round it all, why some glass will "sheet" and others won't-also whats the best techniche for these?to me the hydrophobic part doesn't seem to be down to say toughened or laminated glass could it be glass from the middle east which does this?or is it just me

[Slash]

If you use fan jets they are better for rinseing on beaded glass.

[macmac]

I'm don't know the science behind it, although i think there is a lot of rubbish spoke about it on here but, I have houses with identical looking windows i.e. manufactured by the same place & fitted all at the same time. Some sheet & some bead? : :  I find this not to be uncommon either.

Tony

[ftp]

I thought maybe it was something to do with a polishing process. However the hydrophillic properties can be changed to hydrophobic with acid based substances like limescale remover. I have a bottle of mineral deposit remover that will make the glass bead forever after use.
In the print industry metal printing plates are made more water receptive by the use of a gum arabic solution which desensitises the plate. Maybe the same could be used on glass. Possibly acids work as an etch on glass removing something which then renders it hydrophillic. Different types of acid might produce different results?
Need to find an egg head on a scientific site.  

[NWH]

It`s the polishing process and the fact that some glass has tiny tiny holes in it and don`t retain so much therefore they sheet,some glass has the opposite ie larger holes that can obviously not be seen with the naked eye causing them to bead or so i`ve read.

[chris@c.m.s]

It`s the polishing process and the fact that some glass has tiny tiny holes in it and don`t retain so much therefore they sheet,some glass has the opposite ie larger holes that can obviously not be seen with the naked eye causing them to bead or so i`ve read.

Why do some sheet in the middle and not on the edges then ? 

[ftp]

and how come the characteristics can be changed? Has to be some chemical answer i think. Old glass always seems to be hydrophilic.

[ftp]

It`s the polishing process and the fact that some glass has tiny tiny holes in it and don`t retain so much therefore they sheet,some glass has the opposite ie larger holes that can obviously not be seen with the naked eye causing them to bead or so i`ve read.

I think my house is fitted with holey glass 'cos it's freezing tonight!

Do churches have holy glass fitted? 

[kevinc]

don't know why some sheet in the middle but will try to find out,does everyone find find the beading is confined to doors,patios or low level ie below 800mm from the ground (usally testicle height)i,m trying to"find"a common ground just so i can work this thing out-it just nags me me why it happens

[jouk45]

have you ever clean the same windows and next time it does not sheet??  or if you do a window and it half sheets? you clean regular and its never happened before,  usualy couse, is the customer has cleaned in between cleans, with some  miracle never need a window cleaner again spray  i get the truth out of them lol

[kevinc]

old glass is usually drawn or is classed as sheet glass so will be "polished"so to speak anything glazed befofore the mid sixties should be sheet glass after that i don't know,found a site called thewindowman although can't at the moment seem to join the forum to ask this question-seems a good forum more glass and window orientated(double glazing site)but hey worth looking at,maybe the eggheads there would know the answer?

[chris@c.m.s]

Another one I've found is where there is one large window and 2 top openers most of the window will sheet apart from the middle between the openers.

[kevinc]

yeh i've found that-is it just a visual thing ie big brush small area on the openers,could it be the brush?thought of that one/changed the brush no real difference i've gotta get to the bottom of this!

[tomy jackson]

go on window cleaning resources it all no ther for the looking

[karygate]

you tend to find different glass on same houses because some windows will be toughened glass like opening ones on conservatories and these will be beading type and the others might all run because they do not have to be of the higher specification glass.

[macmac]

I also find that there is two types of "beading" glass.
One that beads immediately & one that sheets to start with then beads after rinsing

Tony

[dai]

Mr Muscle window spray makes the glass bead, and maybe other sprays do too.
I do one house where all the window sheet bar two, these two windows are the worst for beading on my round, I asked the owner if he had used any spray, he said that he hadn't, but he had run the hose pipe over them a few times when he was washing his car.
The TDS in this area is in the low 40's, but that must be enough to leave deposits on the glass, and it can only be these deposits that cause them to bead so badly.
There is nothing to be seen on the glass when the windows are dry.