styrofoam and concrete backdrop

I figure its you reading this tI'm ;D you seem to be the man in this section of the forum. well I was lookin at this webpage and this guy made this on a major scale that I want to tone down a little bit. my question is about the concrete. will just everyday concrete work? and can I use just concrete and leave out the styrofoam. and what about ceramic? ive got a kiln and can fire it myself. is there a specific paint for underwater? would it be better to use concrete in the molds for my ceramics? and what should I seal it with or do I need to seal it? okay that's all I can think of to pick your brain about right now. b.t.w. i'm tryin to build my own vacuum for my tank but i'm goin on intuition so I'll tell you how it turns out. thanks Lee

 

Ok, from the top:

will just everyday concrete work?

I see no reason why it shouldn't, so long as you don't use any additives like plasticizers or Unibond in the mix. Most ponds and outside water features are made from normal concrete without any problems. However, my feeling is that he is actually using plaster of paris or something like small crack filler, not concrete. The mix doesn't look like normal cement, and I would think that you would have issues with it not bonding very well, due the the courseness of the structure of cement. He also says to mix according to the instructions on the packet, something that concrete/cement doesn't normally have!

Plaster of paris will give much better results but would need to be waterproofed inside and out to avoid it breaking up in water. This could be achieved using a fiberglass resin, (But beware, this will eat into the styrofoam), or clear varnish on the final two coats, something like a Yaught varnish would work well and can be gloss or matt finish. You could also kiln dry the Plaster of Paris, as you would with clay to seal it.

One other thing that he doesn't explain very well, is whether he actually leaves the styrofoam in the finished mould or not. I would be inclined to remove it when the mould has been completed, giving you hollow, lightweight pieces that could be glued to the tank without any problems. Leaving the styrofoam in may make securing more difficult, as the silicone would stick to the styrofoam better than the outer shell, and time might separate the two!

can I use just concrete and leave out the styrofoam.

My guess is that he used styrofoam to cut down on weight. Concrete is heavy, styrofoam isn't. Don't forget that this is putting weight onto the back and bottom of the tank, so it might make sense to use this. It also forms a shell, rather than a solid lump, and supplies the texture to the final piece.

and what about ceramic?

Even better, if you are able to create the shapes and fire them. The paints could be fired at the same time sealing them in. Again, many ornaments are made from ceramics or fibreglass, so no problem there.

is there a specific paint for underwater?

Unknown. Not used any paints for ornaments or creations myself. My suggestion would be enamel, as this seals with a solid hard coat, that shouldn't leach anything into the water, and that is what I would use in the first instance, should I need to. If you are looking to make the shapes out of ceramics, the colouring would not be any problem, and it would be fired with the shapes in the kiln. Again, he used powder colour with his mix. This takes me back to infants school, when we used powder paints for colouring. This type of paint would be perfect, as it goes into the mix, has to be safe, (how many kids of 4 and 5 try to drink the paint? lol) and the cement would seal it in.

i'm tryin to build my own vacuum for my tank

Is this for evacuating something like the water column? I tried various methods before I came up with a fairly foolproof one. standard air pumps will work, but you need a fairly powerful one and they are not waterproof between the air intake and the electrics. One of the problems I had using these was that condensation will form inside the pump and eventually short out the coil. My final pump worked on a car tyre pump, which I put inside a sealed box with an inlet connector to take standard 6mm airpipe and the outlet being the hose that connects to the tyre with the valve removed and all sealed into the side wall of the box with silicone. This works really well and is very fast, but cannot give you an airstream on a long-term basis as it's too noisy! I am still looking for an alternative that will give me a permanent air-feature inside the column, just haven't found one yet that will do the trick.

 

I did a search here
and found some instructions clearer than the one you have
OR
If your not set on concrete here is a cork background
OR


Carol

 

wow thanks everybody I'm really diggin this website ppl actually answer your questions woo hoooo I'm only dealing with ten gallons so I'm tryin to keep the pieces small but I am trying to make an extra layer thru the center of my tank. tryin to double the floorspace the crayfish has to walk around in I'm thinkin of using some pieces of styrofoam to cut a lattice style floor into (nothing intricate) then jsut pop it out and attach it to to pillars made the same way. anyway I think I'm goin to try to make some molds then fill them with concrete. I just need to see what I can do to strengthen them id hate to wake up one morning and fich a collapsed aquascape adnd a dead crayfish crushed underneath any ideas on what I can reinforce it with (i.e. internal skeleton or a coating to strengthen)? ive got a lot of low-tech ideas but never enuff to time to start one. I bought a microcam the other day and I'm thinkin of waterproofing it and puttin it in the bottom of my tank too. but I don't know if I can focus it to a close enuff p.o.v. to see clearly in the tank. this is my first aquarium since I was 14 so I'm tryin to put some ingenuity into it. give my living room a splash of interest. and my wife can't understand how I spend so much time lookin at my tank. I'm goin with artificial plants for now and have finally gotten the procedure down for attaching them to some of the stones I have in the tank. ive got some arcing platforms that I made for the crayfish to have a multilevel environment and now I'm goin to start attaching plants to them. its ok if I have a veritable forest in my tank, huh? its all artificial so far. guess it can't hurt, but I have to ask. ive also given thought to blacklight paints on the outside of my tank (across the back) as a hand painted background but that's just an idea rollin around in the back of my head.

 

Could you cut a thin sheet of styrofoam maybe slanted with small craters/bumps and grow moss and ferns and some other plants on it for the backdrop? I think I heard that idea a while ago but passed over it because I didn't have a light. My mom got one for me while I was away this summer, so now I am looking at planting my tank. It is a 10 gallon with lights, heater, filter, air, and a small water pump. Currently I have 5 danios and a tiny snail (But I don't know where he is haven't seen him in a while), but I want to get a small algae eater pleco or corycat. Would either of them eat plants? I already have a couple dying Java ferns can somebody tell me how to bring them back to life? They are just kind of attached to some decorations. Thanks
~Hannah

 

Neat idea and I wouldn't consider it a problem either. The plants would get a good hold in the foam, but may, in time, break it up if it's too thin. If you use a couple of ceiling tiles back to back with silicon, they should work fine. You could cut the hollows in the front one, with the back one holding it all together.