Help with a custom-cut lid

[Mikyll1969]

I want to do a DIY custom lid for my Aquarium, since I have wonky placements for the filter and other items... I'm thinking of doing polycarbonate or something... but I'm seeing possible issues with warping and/or bowing due to temp.
Would a 1/4 inch thick piece of poly hold up decent on a 24 x 12 format?
What other issues do I need to know or worry about?

 

[Mikyll1969]

I've seen some comments, in internet searches for the project, that they experienced a lot of warping/bowing with the combination of the light systems and water temp compared to that of the room. I would do glass, but I'm concerned with having trouble getting the various cutouts to work right, or possibly end up cracking the plate while trying to do them.

 

[Brookster123]

The poly will warp, you can use eggcrate or get a sheet of 1/2" acrylic and it to fit. You could use thinner acrylic but you'll need clips to keep it from lifting.

 

[Mikyll1969]

I'm not sure if I have the stuff to cut a sheet that thick, and have it turn out decent; any other thoughts on lid ideas? Due to the tank location, I have to do a custom cut option, of some type, since my filter and other components cannot sit on the back edge (there isn't the needed space available) so I have them on the sidesbut toward the back.

 

[Brookster123]

Do you have a jig saw?

 

[Mikyll1969]

Do you have a jig saw?

Yes, I would need to work out a good place to USE it, but I have one, I'd also probably need to go get some new finer toothed blades, since I bet the ones I have are not ideal.

 

[Mikyll1969]

The poly will warp, you can use eggcrate or get a sheet of 1/2" acrylic and it to fit. You could use thinner acrylic but you'll need clips to keep it from lifting.

OK, I've done some quick looking for acrylic sheets, the 1/2" is tough to find in the right size(looking at 12x24 so I can just trim it down and it's close to the right size for the tank; I'll need to cut off about a half inch in each dimension), and seems a little pricey.

Would 3/8" thick be workable to hold shape? It seems a fair bit easier to get hold of, and much nicer on the cost end as well.

 

[Brookster123]

You can use 3/8", you can get clips to.pin corners and prevent bowing/distorting.

 

[Slappy Kincaid]

You can also get a jigsaw blade specifically made for plexiglass. I'd recommend putting a strip of painter's tape top and bottom where you are going to cut to minimize chipping. Still, they don't work the best.

Other, best option is to use a table saw with a piece of plywood on top of the plexi when you cut it.

 

[Cria]

Most glass lids have a plastic piece that covers the last two inches or so of the whole length of the tank. These plastic strips can be cut to allow filter intake/output, air tubing, heater wires etc. Do you need more than that two inches? If you only have one piece that is more than the 2 inches you might consider what I did:



I have a 75 G that I've been slowly getting ready for my turtle, and I needed an area where there was no glass so that his UVB lamp could shine down without the glass blocking the UVB rays. I got a glass lid off of Amazon that was designed to fit my tank. It came with four pieces of glass, two hinges and two plastic pieces for the back (There is a support brace in the middle from front to back, so each set goes on one side).



I then ordered a custom piece of tempered glass that was the same thickness as the others, but ~8 inches shorter (side to side). I replaced the original piece of glass in the back with the shorter piece pushed to the "middle" end and I have a nice ~8 x 8 inch area for the UVB lamp to shine down. I have the full length back plastic piece on the short piece of glass, so between that and being attached by the hinge to the front piece of glass, it is pretty stable. See pic below.



All that being said, tempered glass is not super cheap (but neither is thick acrylic/plexiglass/lexan (and I'd guess there might be a little bit of a shortage given the amount that has been turned into screens at retail check out counters!). Unfortunately, for all intense purposes, tempered glass cannot be cut, so you can't trim down the pieces that come with the lid. And I would NOT recommend using non tempered glass as it is not nearly as strong, and if it breaks it breaks into shards instead of chunks.

 

[fearlessfisch]

Cria, this is a great response, and I love your setup. I recently built an aquabridge to connect two tanks, and I have debated about how to fit lids when there is a big, glass bridge end going down into each tank. I appreciated seeing how you worked this.

I did want to add to your comment about cutting lids. You wrote, "Unfortunately, for all intense purposes, tempered glass cannot be cut, so you can't trim down the pieces that come with the lid."

Of note, Versa tops for aquariums are made of non-tempered glass, and I think many people do cut them and use them on the aquarium. In fact, one of the youtube videos I consulted while building my aquabridge recommended using a hand-held glass cutter to cut down aquarium lid pieces to use as bridge parts. You're right that the risk of problems if they break is greater than when using tempered glass--but given that untempered glass is routinely used for some of the most widely used commercial lids, I consider the odds low enough to be comfortable using regular glass for both my bridge and my lids.

 

[Cria]

Fearless,
Glad that you found my solution helpful. This is the lid that I have on my tank:
https://smile.amazon.com/dp/B07GFWYLMM/ref=emc_b_5_i


And it is tempered. I also have a cat that occasionally jumps on top of the tank, and I'm not always as careful as I could be, so I erred on the side of caution and got tempered for my custom cut piece.


I didn't want anyone with tempered glass to try and cut it and end up ruining the whole piece, so I figured it was important information to share.


Thanks for letting me know that most lids aren't tempered, that was news to me.



for your bridge, I'd guess the shape of the structure in and of itself is going to lend some strength to the glass.


I saw a post by someone who made a bridge, but it kept leaking. I'm pretty sure they were using acrylic and silicone, which I've heard is a combo that doesn't work. I suggested they chemically weld the acrylic pieces together.

 

[fearlessfisch]

Yikes! I never considered the cat factor. What a disaster that could be!

What you've done here would be perfect for my tanks, so thank you for the template. I was slightly uneasy during the brief time the bridge was on my tanks, because in order to make it fit, I took off the entire back half of the hinged, glass aquarium lids on both tanks. As a result, my lights were positioned a little precariously above the single remaining strips of glass, and a good portion of both tanks was uncovered. That wouldn't be a good long-term solution. Add a jumping cat, and everyone could be electrocuted as well as cut to pieces.

If money weren't an object, I would definitely have used tempered glass ordered to size, or acrylic. I actually didn't even use aquarium lids as recommended by the video I mentioned here, because they would have been too expensive. I paid about 20 or 25 bucks total for a large, single sheet of glass at the hardware store, and the nice man there cut my 12 pieces for me, for free.

You're right--the glass bridge actually FEELS quite solid/structurally sound when put together. That was actually me with the leak, though--in my bridge made of glass. My problem was that I sealed the pieces in the wrong order. I built the bridge on a tabletop with the legs sticking up (U-shape), and the most important, water-bearing seam (the floor of the bridge when inverted and installed) was sealed last. By the time I got to sealing it, I could no longer reach far enough inside the bridge to spread the silicone for a water-tight finish. I was getting tiny drips coming from the middle of the floor of the bridge. I am reassembling from scratch now in a different order and hopefully will have learned from experience.