Making our own
aquarium PU background
Report of a ABCV DIY
event performed by Frans Druyts and Johan Thijssen.
|Question: What looks
duller than a bare aquarium with all technical equipment visible? You've
indeed guessed it right, nothing! A setup like this just fails to inspire
the real enthusiast and what's worse, the cichlids won't like it either!
What can we do then to build our own decently
aquascaped tank? We could make a small effort and paint the back (of course
on the outside) of the aquarium light blue, what could make the cichlids
feel a bit more comfortable. The disadvantage is that this makes the tank
look like an ordinary commercial shop tank. Dark (grey-brown) paint is one
step further in the good direction. Prefab PU foam sheets will look even
better and enable you to create comfortable dark hiding spots in the back of
the aquarium, but although the ugly technical equipment don't attract
attention against such a dark background, it still remains visible! Of
course a huge setup of large rocks can be used to hide the most disturbing
elements, but there is a better solution: Non-toxic 2-component PU foam!!!
Non-toxic 2-component PU foam is a very good material
to build a 3D background. Although it doesn't look as neat & real as the "Back
to nature" background, it does a fantastic job at a very reasonable price,
and it can be custom fit in all existing aquariums. With your own
imagination as a guide, you can create a very nice looking background with
all filtration, hiding and heating elements built in! Also wood branches can
be attached in the background, what gives a very realistic effect in new
world cichlid tanks. BTW this material is also marine proof!
The principle is rather simple: The chemical reaction
will produce heat that will cause a specific (3rd) chemical to cook. The
tiny gas bubbles that arise causes the mass to swell. When the chemical
reaction is complete a closed-celled foam is formed.
There is one WARNING
though: Clumsy persons are advised not to try this DIY project, as the 2
components are very sticky when they're finally mixed together, and the
project could end up in a gaint mess!
A background built-in in an existing plywood tank
What PU do we need to make a
background like this?
Probably the biggest problem is the
worldwide availability and the difference in commercial names (Hmmm sounds
familiar, ain't it?) , but we simply need the 2 separate components, and not
the product out of a spray can because we must add dyes during the mixing.
Straight out of a spray can the PU looks pale yellow, what's not exactly a
natural color. Make sure to search after NON-TOXIC 2-component PU. Here in
Belgium this product (resinol270 and urestyl10) is available in a
specialized polyester shop.
What else do we need?
Very important: A second person
( to help with the mixing).
Solid plastic mixing (about 250ml) cups
that can be deformed without breaking.
Small plastic measuring cups for dosing
equal quantities of product (the containers from 35mm photo film are ideal)
Wooden mixing sticks (for mixing of
Oil paint & syringe (to add drops of
colouring matters to the PU mixture - can also be mixed with one of the
components before mixing; what gives a uniform coloured background = less
Top coat (epoxy paint) & Paint brush (to
apply the epoxy paint)
Acetone (for cleaning)
Gloves (to protect your hands)
Pieces of glass (to keep the background
Large PVC tubes, pieces of polystyrene
foam, wooden branches. (they can be moulded in to create caves and 3D
Large plastic foil (to protect the
worktable from spills)
|Where will we make the background?
Before we rush into the mixing of the PU, we will
choose where we want to make the background. It seems logical that it's
moulded into the tank, but sometimes this isn't possible. When a tank can't
be moved, it's wise to mould the background in a similar sized wooden frame
with a plastic bottom. When the construction is ready, it can be cut out of
the frame (the plastic is easy removable), cut in 2 and glued in it's place
in the tank with silicones. The joints can be finished with a fresh amount
of PU mixture. When we mould the background straight into the tank, it's
advisable to glue T-shaped glass pieces to the back window to prevent the
structure from breaking loose.
The back of the tank ready: the surface sanded & degreased
and the T-shaped glass pieces glued with silicones will ensure a good
attachment of the background!
How will we work?
To avoid mistakes all recipients are marked with
coloured tape or a felt-tip. After all we wouldn't want the chemical
reaction already starting in the measuring cups. Take 1 cup of both
components, add some drops of the oil paint, mix very well and pour out the
mass in it's place. The mass will expand and will cover all protrusions.
When adding several layers you can hide filter compartments, air tubes tubes.
Also PVC pipes can be moulded in to create caves. Take care not to create
traps where cichlids can get locked in with a waterchange! Wooden branches
can be fastened in the stiffening mass. As you see there are a lot of
options and your own imagination will be the only limit to creaty a
magnificently looking 3D background
The 2 cans ready for use & Johan measuring a certain
Johan pouring the 2 components together & mixing the
The finishing touch
After the background got ready
we will add a protective layer. In this project the transparant G4 (some
kind of epoxy paint) is applied with a brush. A small bit of green paint can
be added to imitate algue growth.
Frans pouring the mixture in it's place & modelling the
Frans standing in front of his creation! This will become
one of the many show tanks on the next ABCV show
Enjoying the result!
Hopefully everything became a
succes, and after some waterchanges to be absolutely sure no chemicals will
be left in the water, we can start cycling the tank and finally adding our
first fish, so we can start enjoying our own creation!