sfsuphysics
Active member
Ok, I finally did it, I made my external overflow. I went the brave but stupid route too and did all the cutting and stuff with a nearly full tank of water. Removing everything was not an option, so what I did is I used a couple 2x4s to brace the tank to prevent (flatten) any bulges, that and a 5 foot long external overflow ends up being a brace anyways so now I probably have less bulging atleast along the back.
Now I made the overflow from tap plastics scrap material, got 2 pieces for about $10, and managed to chop one into three 4" x 20" , and the other into two 4" x 30" pieces. I then glued them together to make 2 long pieces around 5 feet long each. I reenforced the bottom on with a small piece. Weld on #16 is my friend, none of that liquid crap! I'm unsure if it's as strong, but man it's forgiving for mistakes. Now ordinarily you probably wouldn't want to make a long piece from multiple smaller pieces since all the joints are going to be weak points but I figured there wouldn't be more than a couple inches of water at any one time in there so shouldn't be an issue
Here's the outerflow finished
Then I went to the issue of cutting the slots in the back of a tank, I was thinking about cutting one long slit along the entire back but decided against that because I figured there might be a strength issue with the top. I had my girlfriend with a net to scoop out all the acrylic shavings that went into the tank (luckily it floats) and she did a bang up job of keeping the junk out! While this can be a one person job, it's way easier with two.
I used a rotozip to cut the slots, and used the 2x4 brace as a level for keeping my cuts more or less straight. One problem I realized is I cut a bit too much away (I really expected the water to come in much faster but man if those overflow slots didn't just suck water out! So what I did so my waterlevel wasn't too low I glued some smokey acrylic along the back so now there's a much smaller slot, but the semi-transparent nature lets me see through if water is flowing nicely.
Here's the overflow itself, I drilled for 2 1.5" bulkheads, although 1 bulkhead is more than sufficient to keep up with the water flow, but I left the second one I stuck in there and capped off (white pipe) incase I feel like adding the plumbing at a later date (incase I add a surge system or a larger return pump).
And inside the tank, the slots really suck the entire surface down into the sump
right side
center
left side
Now I made the overflow from tap plastics scrap material, got 2 pieces for about $10, and managed to chop one into three 4" x 20" , and the other into two 4" x 30" pieces. I then glued them together to make 2 long pieces around 5 feet long each. I reenforced the bottom on with a small piece. Weld on #16 is my friend, none of that liquid crap! I'm unsure if it's as strong, but man it's forgiving for mistakes. Now ordinarily you probably wouldn't want to make a long piece from multiple smaller pieces since all the joints are going to be weak points but I figured there wouldn't be more than a couple inches of water at any one time in there so shouldn't be an issue
Here's the outerflow finished
Then I went to the issue of cutting the slots in the back of a tank, I was thinking about cutting one long slit along the entire back but decided against that because I figured there might be a strength issue with the top. I had my girlfriend with a net to scoop out all the acrylic shavings that went into the tank (luckily it floats) and she did a bang up job of keeping the junk out! While this can be a one person job, it's way easier with two.
I used a rotozip to cut the slots, and used the 2x4 brace as a level for keeping my cuts more or less straight. One problem I realized is I cut a bit too much away (I really expected the water to come in much faster but man if those overflow slots didn't just suck water out! So what I did so my waterlevel wasn't too low I glued some smokey acrylic along the back so now there's a much smaller slot, but the semi-transparent nature lets me see through if water is flowing nicely.
Here's the overflow itself, I drilled for 2 1.5" bulkheads, although 1 bulkhead is more than sufficient to keep up with the water flow, but I left the second one I stuck in there and capped off (white pipe) incase I feel like adding the plumbing at a later date (incase I add a surge system or a larger return pump).
And inside the tank, the slots really suck the entire surface down into the sump
right side
center
left side
