In this article you will learn how to build a 3d corner background for your aquarium out of styrofoam and fiberglass.

Supplies needed:

• 2 Paint brushes
• 3 cans of spray paint(black,grey,brown)
• 1 tupperware container
• Spoon
• 3 liters of fiberglass resin and 70ml of hardener
• Fiberglass cloth….. not mat
• Box of rubber gloves
• 1 sheet of styrofoam
• 1 liter of acetone
• 1 tube of GE I silicone
• 1 can of “great stuff” foam
• Blow dryer

Since i have a corner bow front tank, i wanted it to go into the corner. I also decided i wanted it to be a tree trunk with its roots extending out.

So on with the carving. I used just a basic knife with a serrated edge for all of the carving. First the trunk, which as i carved it, I kept changing my mind on the outcome so i did just a basic half cylinder and figured I’d do the rest once i see how the roots look. I also used the great stuff foam to hold all of the styrofoam together and it does a great job at that. After I did the trunk I cut up a few pieces of styrofoam and glued them together, then set them in front of the trunk to get a better idea og how it all was going to look.

I forget to take pics of some of the steps and progress, but i got most of them(Click To Enlarge)

After the carving and sanding was complete I fitted the background into a corner of my house to insure a snug fit. The carving and gluing took 3-4 hours over 2 days to complete and was the most labor intensive part of the whole build, however, its not all that bad.

So on with the fiberglass. I used fiberglass cloth, which is suppose to be a lot easier to work with than other methods. The directions say to use 10ml of hardener for every liter and it will cure within 3-4 hours. I used double that and it hardened in one hour. I would not use anymore than that though since it produces a lot of heat and may harden too fast and become brittle. Directions also say to apply the mixture to the part your fiber glassing over, then put the fiberglass over that and paint or smooth more resin over it. That seemed like overkill so i just dipped my strips of cloth into the mixture and put it directly onto the styrofoam by hand while smoothing it and shaping it. I did find that cutting the cloth into strips rather than trying to do it in big pieces was a lot easier. I cut mine into 3X8 inch pieces. I also made sure to where rubber gloves, which is a must.

After getting it all covered, I waited until it was almost fully cured and did it all over again.

This is after the first layer:

I then waited a couple of days to remove the styrofoam since I planned to use acetone to remove a lot of it. This stuff also stinks, but, it’s not as bad as the fiberglass resin. I removed most of the styfofoam by hand and with a knife, and then used the acetone.

Most of the styrofoam gone:

For the paint I used krylon fusion. I done the first coat in black, and then the second in brown. I then combined them both for a more mixed color before adding a light mist over grey over top of that. After painting it all, i sealed the whole thing in one more coat of fiberglass resin and used the blow dryer on a low setting to help with curing.

Upon placing it into the aquarium I felt it was far too shiny so out it came. I had to wait for the silicone to dry before giving it a light sanding to take the shine away. Once completed I siliconed the background into the tank.

Thanks to joey020283