I bought two fiberglass-with-acrylic-window 4500 gal tanks from Dolphin Fiberglass, Homestead, FL. I had to fiberglass them together as they came in 4 pieces each. What I've learned is that once the finish (colored) resin cures, one cannot simply brush new resin over it and hope it sticks. It won't.
The finish resin has wax in it, which migrates to the resin-air surface during the curing and thus forms that hard, glossy finish to the cured resin. To apply more resin over it, one must sand down the wax layer, which is quite laborious. Otherwise, it will start flaking off sooner or later. I know this because I've gone beyond the sanded areas when I seamed my 4500's together.
So, if I had to guess, this may be what happened when they were making your tanks. The crookedness of the window on 600 gal is obvious and does not help trusting their workmanship.
Even if this is what happened, this may not lead to a leak because the pigment-and-wax containing finish resin is the last layer applied (and it does not contain any glass fiber or cloth). The main wall is made with the same resin but lacking the wax and the pigment. It's kind of brownish, semi-opaque in color. So chances are, that resin must be good - hard to imagine them misformulating or misapplying both resin kinds.
So I think you should not get a leak and structurally these should be fine. The aesthetics may take a hit however small or significant.
The finish resin with the pigment and wax does add to the overall watertightness of the wall, I was told by the Dolphin FG.
You can read about all this in my thread I had linked above and it is found in my signature, first link. Just skim through the pages until you see huge blue tubs being fiberglassed together in the photos.
The finish resin has wax in it, which migrates to the resin-air surface during the curing and thus forms that hard, glossy finish to the cured resin. To apply more resin over it, one must sand down the wax layer, which is quite laborious. Otherwise, it will start flaking off sooner or later. I know this because I've gone beyond the sanded areas when I seamed my 4500's together.
So, if I had to guess, this may be what happened when they were making your tanks. The crookedness of the window on 600 gal is obvious and does not help trusting their workmanship.
Even if this is what happened, this may not lead to a leak because the pigment-and-wax containing finish resin is the last layer applied (and it does not contain any glass fiber or cloth). The main wall is made with the same resin but lacking the wax and the pigment. It's kind of brownish, semi-opaque in color. So chances are, that resin must be good - hard to imagine them misformulating or misapplying both resin kinds.
So I think you should not get a leak and structurally these should be fine. The aesthetics may take a hit however small or significant.
The finish resin with the pigment and wax does add to the overall watertightness of the wall, I was told by the Dolphin FG.
You can read about all this in my thread I had linked above and it is found in my signature, first link. Just skim through the pages until you see huge blue tubs being fiberglassed together in the photos.
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