Idea for Faux sand bed. Envirotex Lite high gloss finish.
- Thread starter mattjk
- Start date
I missed it if he said the bottom was tempered glass. If so, then I agree that the heat would have been an unlikely cause for the failure. I know, though, that with my custom 6'x2'x2' eurobraced glass tank a tempered bottom was an upgrade. I upgraded to a tempered bottom because of the added strength and the fact that I have a lot of holes for a closed loop.spamin76 said:
Keep in mind, folks, that epoxy is what the most durable surfboards are coated with. Polyester skinned surfboards are more common, but the really bulletproof boards are skinned with a reasonably thin membrane of epoxy over urethane foam and take a serious beating before they crack. A surfboard can go from the hot sun on top of a car rack to the brisk water of Northern California without any fear of cracking.
LOLLefty said:
Sounds like a good plan, though. I'd think that a final layer of epoxy and sand over the joints, once the three pieces are in place, would make for a safe and attractive gameplan. The part that I can't decide is whether I'm concerned enough about trapping ugly and harmful detritus between the FSB and the glass to cast in place instead of making it a drop in bottom. The cast in place method is bound to look better and be less maintenence, but it is a pretty big commitment in a new $2k tank! Ah, the quandries of being at the bleeding edge of progress.
Thales
Active member
I think the risk of trapping detritus is less with pre cast FSB sections, that it is with Starboard - the Starboard bends while the epoxy won't. Also, I just cant see it trapping any significant amount of detritus.
I am also concerned about weight of a cast in place FSB in regards to moving the tank!
Now...on to the bleeding edge of circulation!
hdtvguy
New member
My tanks bottom was not tempered. I really think it was from the very cold tap water that I put in the tank. Winters get very cold here and the cold water supply makes the water even colder.
The thing is I heard cracking all over the tank. I could see the cracking of the epoxy pulling away from the tanks edges.
The thing is it only cracked on the right side of the tank. Was this the weak spot of the glass? I would have to say yes because glass will crack in the weakest spot and then spread.
I posted this in hopes that nobody else has to go through what I did and loose a tank of this size.
The thing is I heard cracking all over the tank. I could see the cracking of the epoxy pulling away from the tanks edges.
The thing is it only cracked on the right side of the tank. Was this the weak spot of the glass? I would have to say yes because glass will crack in the weakest spot and then spread.
I posted this in hopes that nobody else has to go through what I did and loose a tank of this size.
hdtvguy
New member
Well I moved the tank out of the house tonight got someone to haul it away
I took some pictures of the bottom before we got it out of the house.
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00002.jpg">
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00001.jpg">
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00006.jpg">
I took some pictures of the bottom before we got it out of the house.
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00002.jpg">
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00001.jpg">
<img src="http://img.photobucket.com/albums/v248/240FOWLR/DSC00006.jpg">
FastUno
New member
Holy crackling fish tanks Batman!
Just finished mine & got everything in place this weekend & now you guys got me worried!!!!
Method to my madness:
Step1: Cut eggrate to size of fish tank bottom. Hopefully this will provide relief of pressure points & less chances of cracking. Used 2 pieces for this...that meet in the center. I had eggcrate around, what could be cheaper?
Step2: Fill in eggcrates with crushed coral. This allows for a lighter piece, not all of the spaces in there are filled, there is some room to breathe. Not every square mm of expoxy/crushed coral touches the glass (hopefully helps in the prevention of cracking.....heck I could be fooling myself). The partitions of plastic allow a little further resilience. Plus I had a ton of CC waiting to be used for something...finally!
Step 3 Let CC to slightly dry, enough not to disturb it & apply a coat of epoxy/fine sand. Apply sand sifting method at end. By this time too drunk to worry about pictures!
Step4
-let cure for 4 days
-pour in COLD water, yea I just realized this now. Didn't really think about the cold water, but actually was listening for cracking sounds. Remove cold water & pour in more & let sit over 2 days.
I only filled the tank about 4" high, maybe this was the trick? Maybe it was the crate/cc?
-fill up your tank & PRAY!
Just finished mine & got everything in place this weekend & now you guys got me worried!!!!
Method to my madness:
Step1: Cut eggrate to size of fish tank bottom. Hopefully this will provide relief of pressure points & less chances of cracking. Used 2 pieces for this...that meet in the center. I had eggcrate around, what could be cheaper?
Step2: Fill in eggcrates with crushed coral. This allows for a lighter piece, not all of the spaces in there are filled, there is some room to breathe. Not every square mm of expoxy/crushed coral touches the glass (hopefully helps in the prevention of cracking.....heck I could be fooling myself). The partitions of plastic allow a little further resilience. Plus I had a ton of CC waiting to be used for something...finally!
Step 3 Let CC to slightly dry, enough not to disturb it & apply a coat of epoxy/fine sand. Apply sand sifting method at end. By this time too drunk to worry about pictures!
Step4
-let cure for 4 days
-pour in COLD water, yea I just realized this now. Didn't really think about the cold water, but actually was listening for cracking sounds. Remove cold water & pour in more & let sit over 2 days.
I only filled the tank about 4" high, maybe this was the trick? Maybe it was the crate/cc?
-fill up your tank & PRAY!
Wow. Those are mind blowing cracks. I've never seen a crack in glass quite like the serpentine one in the bottom of your second photo.
It looks like the resin separated from the glass around the edges. Perhaps it was just the shock of the cold water causing the epoxy to contract that pulled on the glass and induced the stress? I think others may have speculated about that, but these pictures seem to show that something pulled the two apart. I can't imagine the density of the resin and sand would be light enough for it's own bouyancy to pull it upwards enough to lift from the glass, so something caused this. The fact that there are multiple unconnected cracks means that there was distrubuted stress, too, not just in an isolated area.
hdtvguy: Thanks for posting the pictures. I know it must be pretty painful to dwell on.
FastUno: Yours looks like it turned out well (knock on wood). How much depth do you think there is above the eggcrate?
It looks like the resin separated from the glass around the edges. Perhaps it was just the shock of the cold water causing the epoxy to contract that pulled on the glass and induced the stress? I think others may have speculated about that, but these pictures seem to show that something pulled the two apart. I can't imagine the density of the resin and sand would be light enough for it's own bouyancy to pull it upwards enough to lift from the glass, so something caused this. The fact that there are multiple unconnected cracks means that there was distrubuted stress, too, not just in an isolated area.
hdtvguy: Thanks for posting the pictures. I know it must be pretty painful to dwell on.
FastUno: Yours looks like it turned out well (knock on wood). How much depth do you think there is above the eggcrate?
spamin76
Premium Member
I am thinking about doing a drop in acrylic bottom - this makes me a tad nervous. I might make a mold of the tank. Not sure yet. This whole deal with HDTV guy makes me a bit nervous - I hope it's some consolation HD that you may have saved other peoples tanks from the same fate Sorry you had to be the one to have it go bad.
Sorry you had to be the one to have it go bad.
