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First 3d background help

2432 Views 16 Replies 6 Participants Last post by  Chunkanese
Hello this is my first post! i am planning on making a 3d background for my 20 gal tank. i have a bigger tank that i plan on doing too but start small ya know. I am just doing a rock wall type background greyish coloring.

So i have some questions,

as far as foam what kind of foam do people prefer? the kind from appliance boxes or the harder stuff you can get at craft stores or like home depot?

What works best to shape? i.e. knife, razors?

what kind of glue to use to put the pieces together?

how to make work with hang on back filter? i want to seal to the glass so what have other people used to make the intake fit but not show much

what kind of cement to use?

what kind of paints to use?

what kind of sealant\silicone?

can someone explain the curing process for cement and paint.

anything else i should watch out for, tips?
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A 20 gallon is a bit small and limits you to your design. Simply it will take away a lot of space and you will really only have 15 or so gallons of swimming space. Anyway to incorporate a hob filter you can either hide it or somewhat build around. Get some thin strofoam sheets from home depot. Cut it to the size of your tank. Draw on where you want your rock pattern then take a steak knife and carve out the rocks. Once you finish that you can either use a hair dryer to smooth out the cuts you have made or if your happy skip this step. Now if you feel you want to hide your filter intake you can cut out a channel on the back with an intake hole on the bottom. Do this by adding second layer pieces on the back. These pieces you will be siliconing to your tank so keep that in mind. Then you will need some cement. Make a thin mix, so make it watery close to milk or water thickness. Do an entire layer of that. Let dry 24 hours. Once it's dry make a thicker mix this time. Apply a layer of that mix. Let dry 24 hours. You can use colored drylock to basically paint your background or add cement colouring to your mix. You won't need paints but krylon latex paint is safe. To silicone go to Rona or home depot get Ge silicone I. It's safe once you let it cure for a couple days. I'm about to make my next background. Will post pics.
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thanks for the suggestions, i know it will take up space, i dont plan on making it super elaborate, its a barb tank. How long does the cement need to cure for? will there be toxins or anything from the cement?
Skip the whole cement process and use Drylok. Much much easier. There are many links to BG's using this process. Good Luck!
+ 1 , skip the cement and use drylok instead. Faster, easier, and no leaching or PH spikes.
what is drylok and how do i use it on the styrofoam?
Drylok is masonry waterproofer. It has the look and consistency of white latex paint - but it's safe for fish. Mix with various cement tints (black, brown, rust) in different containers to achieve a palette of different rock-looking colors. Then, just paint it onto the styrofoam.

The tank in my sig video has a background using Drylok.
oh sweet what is the curing period for that? any special process involved to cure it?
Give it a few days to dry. It'll take the silicone longer to cure, and by the time that's done, the drylok will be hardened and ready.
have you had any specific success with colors when using the cement colors? Like mixing certain amounts of each creates this look? or no any examples? im going for like a riverbed pebble look with brown blacks and greys
It takes some experimentation to get the shades and colors you want. With black, brown, and rust tints, you could do just about any shade of gray, brown, etc. I got a piece of cardboard and tried different mixes and combinations to see what looked good. You can also brush very lightly with water to get some interesting effects. Just experiment and see.
A good glue to hold styro to styro is gorilla glue. Dries fast and holds great. Way faster than siliconing pieces together. It also accepts the drylok better than silicone.Good Luck!
DIY Background build threads here.
Here are some pictures of my background, i think it turned out alright for my first attempt and good news 24 hrs in the tank and it hasnt rocketed out of the tank!

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That looks pretty good, love what you did with the plants :thumb:
Thanks, if you use wooden kabob sticks that are for BBQ it makes the perfect size hole to silicone plants onto
yes i like it alot, those plants add a nice color contrast. Well done.
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