Morning all. I just wanted to share my experience with all of you on how to remove mortar from windows as there isn’t a lot out there.
Please reference Pics as well - For this job Mortar was on the Windows for 6 months. I informed the client of the scratches, they really didn’t care. After a thorough inspection, I was finding scratches on the windows before I even touched them.
Quite the process and this is something you want to be paid hourly for. You also want to sign a waiver or something similar if possible. I used a product called Cement Off from Titan Laboratories, which I purchased from Detroit Sponge and Chamois here in Wixom, MI. About $50 a gal including tax.
Technique -
Get the window wet with water ( you want a garden hose with nozzle) and the surrounding areas where the runoff will be. Squirt Cement Off on window and reapply Cement Off if it starts to dry out. Consistently spray surrounding areas for runoff. Let Cement Off work for 15 - 20 mins. I was doing about 4 - 5 panes every hour. After 15 - 20 minutes garden hose all windows and drive run off into the ground. Safely nudge/ push removing mortar off of window. Clean window as necessary.
Products:
Cement Off
Rubber Gloves
Safety Glasses
Plastic/Metal Razor
Garden Hose
Whenever I have used cement off, I put in on a sponge and dab it on the cement. Seems pretty wasteful to me to “squirt” it on the cement. I have only found it by the pint.
I also dab off the cement, not rubbing it around with a scraper, which IMO, could cause scratches.
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Great name. Must be from Indiana?
Yes, I would squirt it on the cement then “catch” it with a sponge to not be wasteful. Dabbing off the cement did not work, quite frankly it was very tough. The mortar was on the windows for 6+ months and through a Michigan winter. Scratches may have been inevitable.
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wet for 15-20 mins lol
it would dry in my climate in 15 seconds
might be able to pressure wash mortar off if this technique wouldnt work in your climate.
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Looks like you did a nice job. Not sure they had this product back when I was doing most of my glass work. If so I never got around to trying it.
In the old days a razor was one of the better ways to cut concrete off glass. Kind of a conundrum though having to resort to using a razor to clean tempered glass - and of course a lot of sliders get concrete on them when the concrete guy pours a slab under them. What I ended up using was vinegar. The higher acetic acid the better. On dry concrete. Don’t clean it at all. Let it soak and then brush off as much debris as possible with flowing water and soap - using a brush so you don’t lodge particulates in your t-bar. Whatever’s left I’d carefully use a blade on - never cutting upwards - I cut side to side holding the blade diagonally, small strokes only what’s necessary. If there’s a lot of debris rinse & soap as you go so you don’t lodge particulates in the blade. If you wool it be careful you don’t pick up debris in your wool by getting to close to the edges. Wool won’t scratch glass but a chunk of concrete you embed in your pad from scrubbing the bottom edge sure will.
Goes without saying I’d explain it all to the customer before hand and make sure they understood how problematic removing concrete can be. If all you do is cut concrete off glass you run the chance of creating a permanent ‘shadow’ where the surface is destroyed by physicality breaking the bonds on a molecular level. As I recall Portland cement can bond to glass in as little as three to seven days. How often is the glass guy called immediately after concrete gets on the windows?
Vinegar seemed to help break the bonds and minimize damage from my experience, and in a pinch way better than just cutting it off with soap, but if cement off works like you say seems like that’s the best way to go to me. Almost makes me want to find some windows with cement on them to see if it actually works. Almost…
