Probably the most annoying of all damage to glass is Weld or Grind Spatter. Not only because it takes twice as long to repair as any other form of scratch or mineral damage, but because there is no reason for it to happen in the first place. If contractors were grinding or welding close to a wooden floor, they would take measures to protect it, so why not glass.
When using a grinder on metal, sparks fly off the metal with considerable force. These sparks contain tiny particles of metal that have been removed from the object being worked on. It is very hot (that's why it is red and yellow in colour) and hits the glass at speed. Because of the heat and force, the metal particles stick to and burn into the glass, sometimes upto 0.7 / 0.8 mm deep. In glass terms, that is very deep.
Weld Spatter is a little different, although the effect is pretty much the same. The weld slag (gas or mig) is much hotter than grind spatter and although it does not hit the glass with the same force as grind spatter, it still burns itself into the glass, again to about the same depth as grind spatter.
Grind spatter is by far the more common of the two. Due to the time it takes to remove from glass, repairing either weld or grind spatter really only becomes cost effective for for large externally glazed or bespoke units.
Repair Solutions: for large areas or multiple units
If you have a large area or multiple units to repair, our advice would be to call a professional glass polisher. As they say, time is money and this includes your time.
It would be misleading to try and give a general cost of repair on a website as each scratched glass situation is different, but for large areas of scratched glass or for multiple units, services of a qualified glass polisher offer genuine savings, often in excess of 80%, on the cost of replacing scratched windows and doors.
For areas greater than 50 sheets of A4 we would recommend you ask for a senior technician to visit your site to assess the works required and provide a written quote.
The Cost Effective Option. On paper, professional glass polishers are not the cheapest glass polishers on the market, but the reality is that a Guild qualified glass polisher will repair a least twice the area than that advertised by most others othering scratched glass repair services. This makes our members extremely cost effective and our members are still the only glass polishers able to guarantee distortion free repairs.
Repair Solutions: for small areas or single units
For smaller areas or for single unit repairs, employing a professional glass polisher may not be the most cost effective option. You might find that a D.I.Y Scratched Glass Repair Kit would be a more cost effective option for you.
A quick note about D.I.Y Kits. There are a number of kits on the internet that claim to remove scratches from glass. Please be careful. Kits with just a felt pad and polishing compound will not remove anything other than very, very fine hairline scratches. The same can be said for kits containing 'Jewlers Rouge', polishing powder, usually pink, which you mix with water.