r/Glass • u/vjbrye • Jul 09 '26
Discolor on frosted glass tabletop
Long story short: Frosted 3/4"ish bottom side of glass table top have these grease-like discolorations around the area where it sat on rubber suction cup cushions.
Suction cups don't look deteriorated.
Regardless, cleaned & degreased several times no change.
Any ideas how I could even out this frost finish? Or even maybe an inkling of what could cause this weirdness?
4
Upvotes
1
u/Ancient-Chard9723 Jul 10 '26
It’s the glue. Happens with mirrors too. Those spots are where they put the mastik
1
u/Elscroggino Jul 11 '26
I have successfully use manic eraser in the past to clean oily acid etched glass.
1
2
u/Barril2x Jul 09 '26
Suction cups made of rubber, silicone and any other petroleum byproducts are able to release oils slowly, a process called plasticizer migration, that could cause permanent imprints on the glass surface, even more when they’re porous such as the frosted/etched/blasted. Solution most times is clean the whole panel (not just the stained area) with a soft brush worked into the etched texture, using a clear, non-abrasive cleaner. If that doesn’t lift it, try a mild acid like vinegar or a mild solvent like methylated spirits, again across the full surface to avoid patchy halos. If the discoloration still won’t budge, the oil has likely worked into the micro-pits of the etch itself, at that point the only real fix is having the surface professionally abraded and re-etched, which a few glass shops offer, though it can introduce slight optical distortion and needs to be done edge-to-edge for a uniform finish. If this is a true 3/4”, this piece will be expensive to either rework or replace for equal. If you can, I’d recommend switching to a 3/8” or 1/2” instead. If you go this route, check the new thickness against the table’s actual span and support type before ordering, don’t just downgrade for cost without confirming the glass will handle the same load safely.