Diamonte vs. Starfire - why is it pitting?
- Thread starter Greg Hiller
- Start date
Greg Hiller
New member
I have spoke to AFY, they are concerned, but don't know what to make of it. I sent them the following photos as well.
Astraea snail in this one for scale:
Astraea snail in this one for scale:
john rochon
New member
I'm wondering if those pits were already there but just showing up now as algea grows in them. I have a scratch that wasn't visible at first until algea started to grow in the crevise. it almost dissappearse when I clean the glass.
I also believe that these ultra clear glasses are softer [scratch easier]. I have tempered STARPHIRE and its the only pane that is scratched.
I also believe that these ultra clear glasses are softer [scratch easier]. I have tempered STARPHIRE and its the only pane that is scratched.
Greg Hiller
New member
The pits actually show up because they catch the light, not because algae is in them.
>Can you actually feel the indentation on the inside of the glass?
Was there nothing there before?<
You cannot feel the indentation with your finger nail, too small, you can however feel it with the point of a razor blade as you run over it.
>Can you actually feel the indentation on the inside of the glass?
Was there nothing there before?<
You cannot feel the indentation with your finger nail, too small, you can however feel it with the point of a razor blade as you run over it.
Large Polyp Dave
New member
nreefer who made your tank?
I don't know, the tank construction is top notch and I am very happy with everything Will did for me. I am not sure if this is a Diamante problem or if the glass is just softer than what I am used to so it scratches easier. Either way I take extra care when cleaning the glass now.
bond007069
New member
After reading this thread, i checked out my 120 All Glass Aquarium 48x24x24 and noticed 2 small marks simillar to the pics.
Tank was purchases in May 2005. I have no sand in the tank.
I tried to feel the mark from the inside and outside, but it just felt smooth.
Any word on what it is?
Tank was purchases in May 2005. I have no sand in the tank.
I tried to feel the mark from the inside and outside, but it just felt smooth.
Any word on what it is?
I have some ideas, but nothing conclusive. If there was a preexisting defect in the glass surface, such as small inclusions/voids from the manufacturing process, these defects would serve to raise the local stress in the glass. The urchin/ scraping might be enough to chip the glass like that, as it passed over the preexisting defect. Otherwise, the bow in the tank could do it. What leads me to suspect a manufacturing defect is that the chips are all aligned in the same way. You could have introduced the defects by scratching the glass with the scraper to begin with.
To clarify, brittle ceramic materials, like this glass, fail mechanically in a catastrophic manner. Cracks have no ability to blunt their tips like they do in metals, so once they get to a critical size, they propagate at the speed of sound in the material. Cracks form where the stress overcomes a critical stress of the material, which in glass happens at defects (there's always defects). So fracture in ceramics is statistical... what is the chance that there is a defect in the highest stress region? In fact, thicker ceramics in tensile structural situations will often fail under less load than thinner specimens. This is because with more volume, there are more defects. If you tested many ceramic samples, you'd find a large spread in the loads under which they failed. With metals, there is a much smaller window in which they always fail. Metals can plastically deform (yield) to lower stesses at crack tips. Defect free, a sheet of glass is much stronger than acrylic. Glass and other ceramics are terrible engineering materials for tensile situations, as defects are very unpredictable.
To this end, if this low iron glass is softer than other types, it is less likely to chip.
Again, are there any differences in the distribution of the chips across the panel? We should really be calling these things chips, not pits. Assuming the panel is not tempered, then the inside is under compression and the outside under tension. Tempering introduces a compressive stress on the outside thickness of the panel, so some deflection is required to reach a tensile situation, and in essence the panel is stronger. Chips like that on the outside would have me much more worried, as tensile stresses tend to widen/open cracks, where compressive stresses tend to close them.
It's really important to know if any new chips are forming, and if they are, if there is any correlation with scraping the algae off. If you get any new information, let us know...
G1
To clarify, brittle ceramic materials, like this glass, fail mechanically in a catastrophic manner. Cracks have no ability to blunt their tips like they do in metals, so once they get to a critical size, they propagate at the speed of sound in the material. Cracks form where the stress overcomes a critical stress of the material, which in glass happens at defects (there's always defects). So fracture in ceramics is statistical... what is the chance that there is a defect in the highest stress region? In fact, thicker ceramics in tensile structural situations will often fail under less load than thinner specimens. This is because with more volume, there are more defects. If you tested many ceramic samples, you'd find a large spread in the loads under which they failed. With metals, there is a much smaller window in which they always fail. Metals can plastically deform (yield) to lower stesses at crack tips. Defect free, a sheet of glass is much stronger than acrylic. Glass and other ceramics are terrible engineering materials for tensile situations, as defects are very unpredictable.
To this end, if this low iron glass is softer than other types, it is less likely to chip.
Again, are there any differences in the distribution of the chips across the panel? We should really be calling these things chips, not pits. Assuming the panel is not tempered, then the inside is under compression and the outside under tension. Tempering introduces a compressive stress on the outside thickness of the panel, so some deflection is required to reach a tensile situation, and in essence the panel is stronger. Chips like that on the outside would have me much more worried, as tensile stresses tend to widen/open cracks, where compressive stresses tend to close them.
It's really important to know if any new chips are forming, and if they are, if there is any correlation with scraping the algae off. If you get any new information, let us know...
G1
Greg Hiller
New member
Goby1,
>If there was a preexisting defect in the glass surface, such as small inclusions/voids from the manufacturing process, these defects would serve to raise the local stress in the glass.<
I spoke to an aquarium manufacturer, not the maker of this tank. He said that when glass is made there is an 'air' side and a ? (cannot remember what he called the other) side. When you build a tank you are supposed to put the 'air' side inside the tank so that it is exposed to water. This is because the 'air' side is less likely to have defects. When the defects contact the salt water over time, the pits or chips form. My tank probably has the air side on the outside of the tank. The good news is that he made it sound like most of this would occur in a span of a few months, so with any luck the chipping is done on my tank. One thing he was a bit surprised about was that the chips did not seem to occur in a pattern. He said that usually a pattern would be visable, like wherever the glass sat on rollers, or something. After speaking with him I went back and looked at the tank, and there does seems to be a bit of a pattern to it. Unfortunately for me, the largest band is right down the centerpoint of the tank.
I will continue to monitor the chips.....I sure hope they don't get worse. :mad2:
>If there was a preexisting defect in the glass surface, such as small inclusions/voids from the manufacturing process, these defects would serve to raise the local stress in the glass.<
I spoke to an aquarium manufacturer, not the maker of this tank. He said that when glass is made there is an 'air' side and a ? (cannot remember what he called the other) side. When you build a tank you are supposed to put the 'air' side inside the tank so that it is exposed to water. This is because the 'air' side is less likely to have defects. When the defects contact the salt water over time, the pits or chips form. My tank probably has the air side on the outside of the tank. The good news is that he made it sound like most of this would occur in a span of a few months, so with any luck the chipping is done on my tank. One thing he was a bit surprised about was that the chips did not seem to occur in a pattern. He said that usually a pattern would be visable, like wherever the glass sat on rollers, or something. After speaking with him I went back and looked at the tank, and there does seems to be a bit of a pattern to it. Unfortunately for me, the largest band is right down the centerpoint of the tank.
I will continue to monitor the chips.....I sure hope they don't get worse. :mad2:
Ocean Image
Premium Member
Greg,
The other side is called the tin side. Glass floats on a bed of molten Tin as it is made into sheets. The aquarium manufacturer you spoke with is correct. The air side should always be in. Shame because it's not as smooth as the tin side...algae can more easily stick IMO.
If you have access to a short wave UV lamp you can determine the tin side of the glass. The tin side will have a fluorescence under the lamp. (Follow UV safety precautions). This is due to the tin oxide residue from the manufacturing process of the glass.
The other side is called the tin side. Glass floats on a bed of molten Tin as it is made into sheets. The aquarium manufacturer you spoke with is correct. The air side should always be in. Shame because it's not as smooth as the tin side...algae can more easily stick IMO.
If you have access to a short wave UV lamp you can determine the tin side of the glass. The tin side will have a fluorescence under the lamp. (Follow UV safety precautions). This is due to the tin oxide residue from the manufacturing process of the glass.
bond007069
New member
Could they be from tiny snail shells projectiled at the glass from the return pump?
Flatlander
Premium Member
I just purchased a new 180 cube style tank. I have a starfire front.
First, {if I may Greg},
, does starfire still have some green tinge when looking down the end or is it absolutely clear. Mine still has some green, albeit lighter than the side panels?
Now talk about pitting and scratching. As it was still dirty from the build, we wet it down and wiped it with a soft cloth. Something I have always done. The sides and back are fine but the starfire has many scratches now. "LOVELY".
Most seem to be on the outside. Is there a polish to help with them? Or am I crap out of luck.
First, {if I may Greg},
, does starfire still have some green tinge when looking down the end or is it absolutely clear. Mine still has some green, albeit lighter than the side panels? Now talk about pitting and scratching. As it was still dirty from the build, we wet it down and wiped it with a soft cloth. Something I have always done. The sides and back are fine but the starfire has many scratches now. "LOVELY".
Most seem to be on the outside. Is there a polish to help with them? Or am I crap out of luck.
