Polishing Compounds for Glass

[aesmith]

Hi,
I hope this is the right place for this question.
The background here is that a dishwasher fault has damaged some glasses, creating areas or bands that are very slightly abraded, looking almost like frosted glass. I was having a try to see if this can be polished off and was having some success using green chromium oxide compound. But that's not quite aggressive enough, although it dulls the abraded areas they are still visible. So I'm looking for recommendations, what is the correct stuff to use on glass? I guess I'd need two grades at least, one to remove the damaged surface and one to restore the final finish.

Any comments appreciated, thanks Tony S

 

[Bm101]

Sure it's not your salt levels that need addressing? Worked here and washing glasses on their own.
There is a product called micro mesh that was developed for repairing scratches on aeroplane windows (plastics obvs.). Its cloth backed and lasts really well and works on metal and wood and plastic etc. Its about the only thing I'd put near glass and expect not get a scratch pattern at less than the very finest grades.
I'd research chemical solutions first. Try bathing an old glass in bicarbonate of soda or vinegar and go from there.
Just a suggestion mind.

 

[lurker]

I have no experience, but I would give autosol a try.
purely as I have a tube for stropping.

 

[lurker]

I think BM is onto something.
Maybe you have a deposit rather than abrasion.

 

[Trevanion]

Once upon a time in Wales, we picked up some 10mm toughened plate glass for a staircase and obviously hadn't strapped it into the van too well and went around a sharpish bend and all you could hear was a "CLANGSHWIIING" in the back as the strap let loose and the glass fell over onto the toolboxes followed by a collective "Oh Sh*t"... Went to have a look expecting to find millions of pieces of glass scattered everywhere but fortunately, everything was in one piece!

Strapped it up properly and took it back to the workshop to inspect the damage, there was a scratch about 4" long that you could visibly see in the raking light and could feel with the touch of a fingernail and there was a cloudy patch where it had scraped against something about an inch wide and again 4" long which just sorta felt slightly gritty compared to the rest of the glass. Got the orbital sander out starting with 320 grit, sanded out the deep scratch and went over the cloudiness and then worked my way up to 1200 with the orbital sander, then moved onto 2000 and 6000 wet hand sanding which still looked cloudy but much better, went over it with autosol and a rag which improved it dramatically and then a touch of Brasso on a kitchen cloth finished it off as it came out of the factory... Sorta...

Alright, it had a bit of waviness to the glass but it was better than buying a new pane!

 

[Droogs]

If it is scratches rather than a build up then the best thing would be the stuff they use these days to repair windshield scratches as the alternative is a lot more steps than 2 polishing compounds. is about 12 with finer and finer lapidary pastes, dremel and lots of pads and water and a week of evenings

 

[aesmith]

Thanks for the comments. BM is correct it was caused by incorrect salt levels, but "she" assures me that's all sorted out and no further damage has been happening. So I would just like to see if I can deal with the existing damage. The green chromate paste almost does it, the damage goes from glaringly obvious to only visible if you look quite closely. Unfortunately it's impossible to see in photos.

 

[--Tom--]

Cerium oxide is the polish for glass

 

[aesmith]

Thanks, I'll follow that up. I've a few other things I can try as well.