Crazing and Stress on Acrylic tanks

kritterG

New member
Hey sea creature traders. this is in response to my disgruntled customer/friend as "Bad tank Builder". =(-
That situation went bad only because the other side of the argument has gone hostile. I can only warrant the tank in this case if the buyer is understanding of the equality in bartering. Give some to get some rule. Asking nicely helps too.
Anyway, I have noticed that some of the tanks I built before (2+ years) have crazed on the edges -2" from sides). Crazing is when the 1/32" surface of the acrylic cracks and has the appearance of cracked ice. This is not due to what material or brand it is as long as it is G --cast acrylic. not extruded.
Most production based tanks are flame polished, polished with heat in order to melt the material and make a nice edge. The material is chemically changed after it is flame polished and when exposed to long periods of pressure, UV light (halides), Heating and cooling, the material stretches and creates crazing. Crazing is not dangerous because it is only the 1/32" surface of the material. It aesthetically looks bad though.
Over the years, I have learned a great deal about acrylic fabrication. Custom tanks with an added charge$ are polished using a buffing pad. This method takes longer then flame polishing but the results are nicer.
Mechanically polishing with a buffing pad does not alter the chemical make up of the material. In theory, this will reduce crazing, time will tell.
 
Adding to Post: The high wattage halides you crazy=) reefers are using cause extra stretchingand UV light on the top of tanks. This affects the front and back of the tanks if the tank has a center brace. This wreaks havoc on the bond between braced top , front and back. Open top Euro tanks dont have this problem, yet are expensive due to material thickness cost. Those people that do have center braces are not cursed though. They probably need to keep the light far enough away from the brace and cool the lamp at its hottest point. I have seen hydroponic halide lights with reflectors that have fan tubes attached directly to them in order to vent the bulb and get the heat away from the plants or tank. These are just suggestions, I have never experimented because a test would take years. Have any thoughts about this? Got to go!
 
gen.....it's over with. for your info there was only 2 MH and 2 vho inside the canopy and they are 18" off the tank. their was also 4 icecap fan on a reefkeeper and it would turn on when temp. would hit 78.0 deg. as for the hairline crack, it started at the joint of one of the corners. it might just be me having bad luck with this tank or the product itself.
 
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