Advice needed on hydrophobic coatings.

Hi all. I was wondering if anyone could help me in the right direction. I sacked the local window cleaner for a really poor quality jobs and attitude to pointing out bird poo still there after 3 visits and have now decided to do it myself. I have decided to use a wfp as I have horrible leaded windows and a 5 stage water filter in the garage already. I have decided that they need a deep clean first as the sills are grey or green. My problem is do I put a hydrophobic coating on after as I have lots of product left from car detailing that I know would last at least 12 months. Would this and a rinse bar on the pole work well on these dirt traps? 

I would say not to the hydrophobic coating. Hydrophillic glass remains cleaner for longer as water, including rain water sheeting down the glass and tends to remove dirt with it.

Hydrophobic glass tends to cause the water droplets on the glass to bubble. Dirt in the bubble is left behind on the glass when the water dries and looks awful.

Agree with spruce, a hydrophobic finish like wax is good on cars to repel mud, flies, dirty water, salt etc. On house windows hydrophilic glass is much better.

What TDS do your filters get the water down to?

I haven’t brought a tester yet. The company said it should be zero for 6 months even with my hard water. It’s a 150 gpd 5 filters with di resin as the final stage which I have as filter water into my fridge and then onto a adjustable pressure pressure washer. It leaves no spots even on black cars in direct sun, so I’ve took his word that it as zero out of the box. On downstairs windows I’ve just sprayed car soap foam on them. Agitated them with a soft brush then rinsed and they sparkle. The sio2 silicons in the soap leaves them with semi waxed but only for a couple of weeks. I’ve read that with wfp you shouldn’t use soap. I don’t know how you’d get dirty windows clean with just water though. Is it just the case that it takes time to rinse all the soap through and off the brush and window? Would I have to wash them every week to have them easy to clean. It’s not as straight forward as I thought. Still don’t regret cancelling the last guy as I’m still sat looking as bird poo now but I have £20 a month extra in my pocket. Thanks for your help. 

The water sounds ok then. It's right you only use pure water, but that's on regular cleans (<3-6mths). First cleans, deep cleans and irregular cleans often need something to help shift the dirt and grime. I use Screwfix no nonsense degreaser, some use ubik, virosol, tfr etc. Any detergent will be ok though- the only thing is after you have used a product you have to remove every trace of it from the window or it will leave spots. That's why it's not practical for regular window cleaning as it can take many times longer. For your own house it's fine though, just brush and rinse very very well after.

Thanx for the advice. Off to order a pole now to get cracking. It’s seems hydrophilic coatings are a lot harder to find than the hydrophobic ceramic coatings. Cheers ??