Hard Water Spots On Glass Block

I had to remove a glass block wall so I can rebuild a damaged shower pan.
The blocks have what looks like hard water spots. I tried cleaning with vinegar, scum-away (purchased at trade show), Spot-x, goof off, even tried oven cleaner. There wasn't even any improvement. These are 4 x 8 Wick blocks. I would like to save them as there is another wall in the same bathroom with same block. Wick no longer makes 4 x 8 end blocks, only 8 x 8.
Thanks

You try CLR?

Yes. CLR produced the same results. = 0

How about muriatic acid & 0000# steel wool. If you have not used this before BE CAREFUL. Well vented, gloves, goggles etc. Also commercial glass shops have a polishing compound they use. A friend at the shop gives me some when I need it.

Thanks for the tip with muratic acid. I was concerned that the acid might etch the block. would soaking in a 50/50 solution be advisable or just apply the liquid and clean with cloth.

Soaked a block in a 70% Meritac acid / 30% water. Scrubbed with an bathroom scrubbing pad. Let dry and washed with soap and water. nothing doing looks the same. Next tried buffing in Turtle wax cleaning compound. Same results.

I now think the hard water (after 7 years) has etched the block beyond repair.

Yes, that is what has happened. As a last resort, since you can't ruin them, is the polishing compound. Good Luck.

Do you think I can give them to some one for target practice

Ya, if they use a big enough gun

Try a glass scratch removing polishing kit. With a powered polisher it could take less than 20-30 mins for a normal size shower.

Great, I'll try that.

Where would you purchase this polishing kit?

Well, dumb as it sounds, try WD-40. Sure seems to work on alot of stuff to remove stains, etc.

I just happen to have some WD 40 in the garage, so I jumped up, sprayed the block and rubbed like crazy. I didn,t work but I now smell like a can of sewing machine oil.

Thanks for the tip

HCL won't dissolve glass, so you're fine. The only one I can think of that will is Hydrofluoric, however while there are other acids that will as well, they aren't available at your local hardware store

I've read that sometimes the metals in hard water deposits bond with glass leaving permanent stains, so you might be screwed. Best bet is to sand the block down and repolish, but that's a ton of work.

Use a product called Zaino, it's there clear-view glass polish. I had the worst water spots from acid rain on a truck I bought and was about to get new glass for it. I got this product from there website about $15 and WOW, it now looks like a new piece of glass.

We had a Glass block partician that had "Permanent" waster spots on them.
I used toothpaste and a dremel with the cloth buffing wheels to get them out.
Before we finished, we broke out the 4 1/2 in angle grinder with a buffing wheel to quickly finish the job.
If you do this, you will have to do them all so they all look the same.
Another friend tried this in Portland after i told him about it. He said in his case, the glass block had a slight haze. But, he said, it was way better than the Obvious water spot look.

Try it in a small area and see if it polishes it out for you.

Try "Nothin's Better" located via auto parts stores. Works incredibly.

Got one of these yet?