WFP left hundreds of white spots after drying (0 TDS, French panes, coastal home) — what am I missing?
Hey everyone,
Had my biggest residential job so far today and ran into a problem I’ve never seen this bad before.
The house has a ton of French-pane windows and is located near the ocean on Long Island. I’m running a WFP setup with a DI tank. Feed water is around 110–150 TDS and I was reading 0 TDS from the DI tank all day.
The windows looked great while wet, but after drying they developed hundreds of small white spots and some hazy/cloudy areas. I ended up having to redo a lot of the glass traditionally. Some of the spots seemed to come off with 0000 steel wool.
A few details:
0 TDS water
Rinse bar
Moderate pressure
French-pane windows with lots of dividers/muntins
House is near the ocean
Spots appeared after drying, not while wet
Didn’t seem to be happening on every window equally
Some windows required steel wool to fully remove the spotting
My questions:
Could a DI tank somehow be causing this even with a 0 TDS reading?
Does this look more like existing hard water/mineral contamination being revealed by the pure water?
Could dirty frames/muntins be bleeding contamination back onto the glass after rinsing?
Is there something specific about French panes that changes how you should rinse them with a WFP?
Any ideas would be appreciated. I’m heading back tomorrow to finish the job and would love to figure out what happened before I do the remaining windows. Thanks.