Any way to repair pitting from a welder?

Hi guys, I haven’t been cleaning windows very long, but this is the second time I have encountered pitting left behind from someone welding. The first time was on a historical building that had a new metal awning put up to cover the front entrance. The second time was on a new home. The builder hired someone to build a metal screen to block the AC unit from street view. Unfortunately both were within inches of the glass. First one was a transom style window, second was a normal 3’ x 5’ window.
At first I thought it was just dirt. When I used my scraper to try and remove the stuff it made that horrible scraping sound that sends fear into your blood! When I touch the spots, they are indentions into the glass (pits). But they also have tiny mounds of glass that seem to be melted onto the window glass? I brought them to the attention of the property manager, and told them I could not remove them. But I could clean over them using a wet rag, and a dry towel. Was not about to tear up my squeegee on these.
Would you guys have tried to do anything different?
I know it wasn’t cement, I’ve run into that (no problem).
My guess is that replacement is the only option??

I use GlassRenue, and have been successful with welding slag. I will tell you that it takes hours to do, so price accordingly

I second Glassrenu


That looks awesome!

[MENTION=171]bumblebee[/MENTION] Will cerium oxide and a car polisher do the same thing as glass renue? And about how long did that take you?

Cerium is not enough. The glass needs to be resurfaced. You need to get down past the damage and then polish it up

Not unless you have days to stand there. The repair I posted was a demo to show the contractor that the damage could be repaired. I used several of the most aggressive red pads GlassRenue has. If you look closely around the X, there are pits deep enough to fill with match heads. I ended up grinding the entire window to get the distortion out. That demo took about 3 hours, the panel took one long day.

Recently, the same contractor had another issue with welding slag. They had to replace the panel because the pits were so deep, I didn’t have enough width to feather out the distortion. GlassRenue is a very valuable tool, but you have to be dedicated to learning how to use it

[MENTION=171]bumblebee[/MENTION] I’ll have to add that to my wish list along with water fed poles!
Thank you for responding and the pictures.

[MENTION=5152]wws[/MENTION] Wow…not sure if that will work on the historic property. The glass is pretty wavy and very thin towards the top of the frame.
Thanks Tim, you guys are awesome!