removing hard water spots

[Tripplett]

I've bought my first panels, nine used 545w bifacials, and one or two have these marks on them which I'm assuming is hard water spots from being stored. The panels don't look like they were ever installed, no tooling marks or screw scuffs. Just some rash on the frames from being moved around, some mud, and a few scuffs on the glass that I hope I can polish off. I cleaned the spot in the middle left of the image with CLR lightly but it didn't make a difference. Before I try vinegar, automotive rubbing compound, or anything else I figured I would ask here first. Thanks for any help you can offer. This is the worst one of the 9 and will probably just be my spare. All panels are putting out full power. Thanks for any advice...

 

[green mountain boys]

Sprayaway or vinegar is what I would use. I have had good luck with both.

 

[MidnightKool]

Those hard water spots can be a pain, but you're on the right track by trying different cleaning methods. Before you go all out with vinegar or rubbing compound, have you considered using a gentle abrasive like baking soda paste? It's less harsh and might do the trick without risking damage to the glass. If that doesn't work, you could also try a specialized solar panel cleaner. And hey, speaking from experience, when water wreaked havoc on my place, alldryus.com really saved the day. They might have some tips for dealing with those stubborn spots too.

 

[seneysolar]

Glass cooktop cleaner might work, its a paste cleaner but does not scratch. Most hardware stores have it.

 

[Checkthisout]

Clay bar like they use on cars.

 

[Lt.Dan]

Careful as the glass has a special coating on it for reflection and ease of cleaning. Any harsh chemicals will remove it.

 

[Tripplett]

I tried diluted vinegar and it didn’t even touch it. Nothing I’ve tried worked. But I have Sprayway, glass cook top cleaner, and a clay bar - so I’ll try a little spot with those.

 

[bluespur]

toothpaste

 

[HarryN]

Try hot full strength vinegar. Same thing that I use to clean my coffee pot.

 

[Nobodybusiness]

I've bought my first panels, nine used 545w bifacials, and one or two have these marks on them which I'm assuming is hard water spots from being stored. The panels don't look like they were ever installed, no tooling marks or screw scuffs. Just some rash on the frames from being moved around, some mud, and a few scuffs on the glass that I hope I can polish off. I cleaned the spot in the middle left of the image with CLR lightly but it didn't make a difference. Before I try vinegar, automotive rubbing compound, or anything else I figured I would ask here first. Thanks for any help you can offer. This is the worst one of the 9 and will probably just be my spare. All panels are putting out full power. Thanks for any advice...

View attachment 182308

I assume it would depend on the composition of the water.
Isn’t it the dissolved minerals that leave the spot?
CLR or something you would use to clean glass on showers.
Not sure if you would want to use anything abrasive because of the coating..

 

[Tripplett]

I assume it would depend on the composition of the water.
Isn’t it the dissolved minerals that leave the spot?
CLR or something you would use to clean glass on showers.
Not sure if you would want to use anything abrasive because of the coating..

This is the way the panels came to me, I'm assuming water spots. But now I'm beginning to wonder as nothing I've tried has worked. The guy I bought them from may have tried to 'clean' off some light spots with something stronger and made it worse.

 

[Nobodybusiness]

This is the way the panels came to me, I'm assuming water spots. But now I'm beginning to wonder as nothing I've tried has worked. The guy I bought them from may have tried to 'clean' off some light spots with something stronger and made it

Have you set them out in the sun to see what kind of output they get?
Might just be cosmetic.

 

[Checkthisout]

This is the way the panels came to me, I'm assuming water spots. But now I'm beginning to wonder as nothing I've tried has worked. The guy I bought them from may have tried to 'clean' off some light spots with something stronger and made it worse.

If nothing else works just use glass abrasive polish. Comes with a little wheel and compound for polishing scratches out of glass. If nothing else works that will.

 

[Brett V]

Mr Clean magic eraser

 

[HalfBaked]

This looks like the same issue I have with some of my windows from being stacked flat horizontally outdoors for 2 years.
I tried all the same things mentioned here before I came to realize they aren't mineral deposits. They are chemically etched. No cure. At least my windows were free. I hope your panels work.

 

[Tripplett]

This looks like the same issue I have with some of my windows from being stacked flat horizontally outdoors for 2 years.
I tried all the same things mentioned here before I came to realize they aren't mineral deposits. They are chemically etched. No cure. At least my windows were free. I hope your panels work.

Yea they work very well. Over rated actually. But then again they’re bifacial. They just don’t look as good as I’d prefer.