Hello,

I have a very cloudy exterior film on my Aquatica glass megadome. Possibly salt etching? or the exterior coating is done? Most of the time you cannot see it in my video when underwater, especially when using my lights but when trying to film ambient or at the higher base ISO of my camera (12800) it's very noticeable.

Any ideas on how to correct this? I have a couple trips coming up this next week, but after I am back I may just send it to Aquatica to have new glass put in. This dome is only 2 years old. I did try a claybar for auto detailing, that did nothing. I've tried vinegar/water that also did nothing. I have ordered some cerium oxide powder and will try that. I know Aquatica uses BK-7 mineral glass but I am unsure if they have an external coating on the dome. I did some searching but couldn't find a solid "how to" to repair this. I do rinse my gear after every dive but my rinse water is from my well, so this may be an issue too.

Thoughts?

You might try this:

And get yourself a supply of distilled water for soaking your camera. That hard well water is depositing minerals like calcium which is causing the spots on your glass.

12 minutes ago, Dave_Hicks said:

And get yourself a supply of distilled water for soaking your camera. That hard well water is depositing minerals like calcium which is causing the spots on your glass.

Yes, I need to make a dunk tank with some distilled water for sure. The well water doesn't help.

There’s been loads of posts on this issue. Definitely worth a search.

Some options;

• 50/50 solution white vinegar and water

• Coke

• Mothers windscreen cleaner

• Brasso

• Cerium Oxide powder (as Dave suggests)

Good luck with them. My own experience is that once the film has been on for a while it’s extremely difficult to shift it. Re-glassing has been my experience.

With new ports now, I follow the Chris Ross routine: good soak and do not let the ports (and viewfinder optics) air dry. Wipe them dry with microfibre cloth as they come out the rinse tank.

5 minutes ago, TimG said:

There’s been loads of posts on this issue. Definitely worth a search.

Some options;

• 50/50 solution white vinegar and water

• Coke

• Mothers windscreen cleaner

• Brasso

• Cerium Oxide powder (as Dave suggests)

Good luck with them. My own experience is that once the film has been on for a while it’s extremely difficult to shift it. Re-glassing has been my experience.

With new ports now, I follow the Chris Ross routine: good soak and do not let the ports (and viewfinder optics) air dry. Wipe them dry with microfibre cloth as they come out the rinse tank.

Roger, I did do some searching but couldn't find anyone that was able to solve it, lol. I tried the 50/50 water/vinegar and that didn't work. Coke is an interesting one, might try that! I am getting some cerium oxide powder tomorrow so will give that a try.

5 minutes ago, TimG said:

Good luck with them. My own experience is that once the film has been on for a while it’s extremely difficult to shift it. Re-glassing has been my experience.

With new ports now, I follow the Chris Ross routine: good soak and do not let the ports (and viewfinder optics) air dry. Wipe them dry with microfibre cloth as they come out the rinse tank.

I now blow the water droplets off my port, I purchased a mini blower designed for computer equipment and similar and it blows the droplets off, follow by a soft microfibre cloth to leave the surface clean and bright. The slats concentrate up as the water evaporates and particularly if the salts in the water are alkaline the can etch glass.

By all means try out the cerium oxide, but if that does not work, I have heard the costs for new glass are not that high.

8 minutes ago, Chris Ross said:

I now blow the water droplets off my port, I purchased a mini blower designed for computer equipment and similar and it blows the droplets off, follow by a soft microfibre cloth to leave the surface clean and bright. The slats concentrate up as the water evaporates and particularly if the salts in the water are alkaline the can etch glass.

By all means try out the cerium oxide, but if that does not work, I have heard the costs for new glass are not that high.

If the cerium oxide works it will remove the coating applied to the glass from factory, I assume? Does the factory coating really even matter optically? I know some domes don't even have coatings or only an internal coating.

I don't know of any domes which are coated on the outside, it would be attacked far too easily.

5 hours ago, ScubaBC said:

If the cerium oxide works it will remove the coating applied to the glass from factory, I assume? Does the factory coating really even matter optically? I know some domes don't even have coatings or only an internal coating.

I have seen it written multiple times and people have enquired and confirmed the coating is on the inside only. The coating won't be doing much for you if it is etched like that anyway.

5 hours ago, Grantmac said:

I don't know of any domes which are coated on the outside, it would be attacked far too easily.

It's mentioned in some of Aquatica's marketing material, but Aquatica's own site says nothing.
It’s coated with a superior Silicon Oxide coating (SiO2) on the convex surface and with a Broad Band Anti Reflective (BBAR) coating on the concave surface.

Coatings are not good for much if the dome is unusable due to mineral staining. Go ahead and do the polishing job.

7 minutes ago, Dave_Hicks said:

Coatings are not good for much if the dome is unusable due to mineral staining. Go ahead and do the polishing job.

Makes sense! I will send it and see what happens, lol. Worse case I re-glass the dome which I was planning on anyway. I will report back for science.

Ok, just FYI for anyone who may stumble upon this thread. The cerium oxide powder works like a hot damn. It's taken me an hour and I have 1/2 the dome done. Scale is completely gone and the dome looks like new. I haven't tested the optical quality underwater but if it's truly not-coated on the outside then we're good. I'll post some photos of the dome once it's fully done too.

For those wondering what product I used, it was a 99% pure cerium oxide powder (photo attached), I added a little bit of powder into a bowl, mixed in some water to get a paste like consistency and then worked it into the dome using a Costco kirkland microfiber cloth (yellow ones) in small circles and then back and forth and then small circles over and over, lol... It takes a TON of elbow grease but it definitely takes off the scale, I am pretty impressed.

Edited September 23Sep 23 by ScubaBC

Hi,

I have been using cerium oxide for years to polish and clean my port glasses. In my opinion, it works perfectly. I use the red ones. This is fine for glass polishing and is widely used in the glass industry. You can buy purer (yellow) more expensive one, but the quality of the red one is good enough polishing portglass. You can also have a look at link:

https://waterpixels.net/forums/topic/3620-nauticam-wet-lens-cleaning/page/2/#comments

The problem regarding polishing/coatings was discussed there already.

Br Markus