DIY Corner Overflow Box

[BillyHalloween]

Thought I might pass this on just in case someone out there was thinking of building their own corner overflow box. I should have taken some pics, but I forgot. I just finished my second one for my second 55 gallon tank. These overflows are positioned in the back left corners of my tanks. I thought I would mention that, because if build one for the right, the holes would be in different places.

I bought a 4' x 4' sheet of 1/8" thick black acrylic and a tube of aquarium sealant. I cut a section of the sheet off with a jig saw. The section that I cut off was 12" x 19.5". I left the protective film on before I cut. I was very careful and slow with the saw so that it would not break the acrylic.

After I cut it, I measured down 1" on one of the 12" sides and I drilled a whole every inch, but I skipped the spot where the 8th hole should be (this is where the bend would be). I measured over 1" from the side, drilled a whole every 1", skipped the 8th hole spot, then drilled 3 more holes. I drilled 10 holes total. I used a grinding bit on my dremel that was about 1/2" in diameter. This works much better than a drill bit. No risks in cracking or breaking it. After that, I measured my tank to see exactly where I wanted my water level to be. I then drilled 3 more holes above those holes to act as a surface skimmer.

I could have drilled all of the holes on the water line, but I wasn't sure how fragile the acrylic would have been. Also, I could have drilled the 10 holes then cut the acrylic down from the top to make slots, but again, I wasn't sure how fragile it would have been. I would probably have had to drill smaller holes to keep wondering bodies out of the overflow.

After drilling, I removed the protective film from both sides of the acrylic and clamped it down on my work bench. I clamped the larger side down and used a heat gun to heat the acrylic sheet up along the line where the 8th hole should have been. When the acrylic heated up, it started to bend. When the smaller section was pointing straight down (90 degrees from the larger section), I removed the clamps and held it in place at the 90 degree angle until it cooled down.

I placed the box in the tank and lined it up exactly where I wanted it to be. I drew on the outside of the tank with a sharpie so that I would know where to put the sealant. I cleaned the inside of the tank (along those lines) with denatured alcohol. I then placed masking tape inside the tank about 1/2" away from the lines on both sides. I also did thins 1/2" away from the sides of the overflow. I did this inside and out. I made sure not to get tape anywhere that would be sealed to the tank. This will keep your seals looking nice and neat. I didn't put tape on the bottom of the tank because I hefty sand bed and it would be hidden from view. After taping, I ran a healthy bead of sealant along the sides and bottom of the tank where the lines that I drew were. I then put the overflow box in place and pushed it firmly. I put on a pair of disposable rubber gloves and used my index finger to smooth the sealant out (inside and out). I was careful not to move the box at all. After smoothing, I pulled the tape off. Taking it off of the box was a little tricky because the box wanted to move with the tape. I just held it in place as I pulled the tape off.

After curing for 72 hours, I filled the overflow up to the holes and made sure there were no leaks. Good to go! I hope this makes sense. If anyone is interested, I don't mind to explain in more detail or give some pointers. I attached the original drawing so that everyone could get an idea as to what I am talking about.

[scubba.steve]

Great write up Billy !!! I may need you help on building one of these in the future if i ever do a sump, or fuge!!! Wait wait..... I COULD use you help building an internal fuge but we would have to do it out of clear acrylic.

[EvilMel]

Thanks!

[BillyHalloween]

Originally Posted by scubba.steve

Great write up Billy !!! I may need you help on building one of these in the future if i ever do a sump, or fuge!!! Wait wait..... I COULD use you help building an internal fuge but we would have to do it out of clear acrylic.

I know of a place downtown that sells acrylic. Not too expensive either. Let me know man!

[scubba.steve]

These overflow boxes are great for someone with a non drilled tank running a pvc overflow :P