fishy_t Posted April 30, 2006 Report Share Posted April 30, 2006 Hi there I'm going to be making a face rock face (with small caves etc) for a 550l tank and was just wondering if anyone on here has done anything similar - I've been looking online and I think the best way to go about it will be to carve out the structure in polystyrene and then apply several thin layers of concrete... any idea's/comments?! Hopefully I'll get sterted this week so I'll let you all know how it goes! Quote Link to comment Share on other sites More sharing options...
Caryl Posted April 30, 2006 Report Share Posted April 30, 2006 Yes others have done it. Easiest is to cut out polystyrene to shape using a hot wire, apply thin coat of silicone then sprinkle sand or gravel over it. Careful of the fumes though and remember it will be heavy when finished but still want to float so you need to anchor it under bracing and maybe make it in 2 pieces for easier handling. Quote Link to comment Share on other sites More sharing options...
Faran Posted May 1, 2006 Report Share Posted May 1, 2006 Hey Thomas, Not sure if I've mentioned this but I have a rock background here made of poly and concrete that you can examine for ideas. It was made with individual "rocks" and then siliconed together and 'creted. The concrete gives it just enough weight to defeat the bouyant properties of poly. Quote Link to comment Share on other sites More sharing options...
Lurch Posted May 1, 2006 Report Share Posted May 1, 2006 you could use acetone to melt the polystyrene away after the concrete has set Quote Link to comment Share on other sites More sharing options...
WEKA Posted May 1, 2006 Report Share Posted May 1, 2006 Hi Fishy I am doing the same thing at the moment for my 550litre cold marine. I plan on keeping some crayfish in the tank so have carved out a couple of caves and a swim thru in the middle. I have made mine out of two 100mm sheets of polystyrene using a hot wire to shape the face and caves. I held the two sheets together with kebab skewers to start with as it helped to be able to separate the two sheets to make the caves and swimthru. I have cut large volumes off the face but it is good to have the depth in places. My plan is to coat the face with a strong cement based product of some kind and then to melt most of the poly out of the back with a hot air gun and then coat the back as well. This will get rid of the buoyancy problem and will create a large cavity in the back were I plan on bringing my return from the sump (approx 5000l/hr) I will make some screened holes in various places for the return water to exit thru the wall. Have done some testing of this method and it is looking good. Hope this helps WEKA Quote Link to comment Share on other sites More sharing options...
fishy_t Posted May 2, 2006 Author Report Share Posted May 2, 2006 I've found this site: http://www.cichlid-forum.com/articles/diy_aquarium_background3.php and think its what I'm going to try, I was thinking About siliconing the background into the tank - I know this might seem a bit of an overkill just to hold it in place but it will mean I don't have to worry so much about the integrity of the structure or about any fish/debris getting stuck behind. (As I will be making the rock surface for my tank background which will be over 1.5m^2 total and about 75cm high I think the polystyrene strength will be good to hold it all in place) I got hold of some polystyrene which is about 15cm deep which gives me plenty of depth to carve out some nice caves... WEKA - when you say you used a hot wire - what kind of wire did you use?! - How did you keep it/make it hot?! I'm probably going to try to make a more sedimentary looking pile with the rocks being more layered with cracks/caves rather than rounded river rocks, but if I could use a wire it would give much cleaner lines than a knife and not a messy I guess! Thanks people Quote Link to comment Share on other sites More sharing options...
WEKA Posted May 2, 2006 Report Share Posted May 2, 2006 That was a great site Fishy I liked the large rock style the guy used - makes me want to start again. I have gone for more the sharp broken rock look. The hot wire is the way to go if you can, there is no mess at all. I am an electrician so it was not a big deal. I got some nichrome wire from an element manufacturer. It is about 200mm long and 1.25mm dia. I connected it to a 12volt 120va transformer - but the transformer needs to be controlled on the input. In my case I used what is called a variac tranformer which allows me to control the input voltage to the transformer otherwise the wire would quickly overheat and burn out. I mounted the hot wire onto a couple of bolts thru one end of a short piece of broom handle and connected the 12v wires on. You can shape the hot wire to suit ie pointed or rounded etc Hope you can make sense of all this - good luck with your project. Maybe we can get some pics later on. WEKA Quote Link to comment Share on other sites More sharing options...
fishy_t Posted May 2, 2006 Author Report Share Posted May 2, 2006 OK, Well I have had a few tonight but I can tell you now that there is no way I'm going to be able to get the whole hot wire thing set up! I think that I'll have to stick with the knife The guy who sold me the polystyrene said that I can use sand paper on it as it’s quite a dense form of polystyrene so its going to get messy but at least I can get some rounded edges on my rocks! I'll stick up some photos as I go.... Quote Link to comment Share on other sites More sharing options...
stompa Posted May 2, 2006 Report Share Posted May 2, 2006 hi fishy .... another way is to use a heat gun or better still get one of those little blow touches use it with care as if you get to close it will melt very fast but with a bit of practice you can get a very good finish and no mess at all..... this is just my way to do it..... it wont work for every one but theres no mess just a bit of smell.. Quote Link to comment Share on other sites More sharing options...
Ira Posted May 2, 2006 Report Share Posted May 2, 2006 hey, Weka, what kind of wattage are you getting from your transformer? I've had someone suggest that an electric blanket transformer would work well, but there are a lot of cheap 25ish watt 12v electric light transformers but that might be a bit weak? I want to set up a hot wire cutter but I'm not sure what kind of wattage I should look for. Quote Link to comment Share on other sites More sharing options...
fishy_t Posted May 2, 2006 Author Report Share Posted May 2, 2006 Thanks Stompa - the melting away suggestion does sound good but I don't think its going to be as precise as I need (Keeping in mind the crevices and caves are for small tang. cichlids) But I might use it to get the overall rock surface and then carve out the cracks... Quote Link to comment Share on other sites More sharing options...
WEKA Posted May 3, 2006 Report Share Posted May 3, 2006 Hi Ira The blanket transformer would probably be too small. My 120 watt transformer started to get fairly hot after a while. I think the blanket one would only be about half the size. I used a hot air gun to try a bit of sculpting and it worked quite well. Cheers WEKA Quote Link to comment Share on other sites More sharing options...
Ira Posted May 3, 2006 Report Share Posted May 3, 2006 How long of a wire and how hot were you using? I'd only need something to get a wire maybe 6" long nice and hot. I think though when I get around to it I'll give the electric blanket transformer a try. Seems the cheapest place to get a transformer. Quote Link to comment Share on other sites More sharing options...
WEKA Posted May 3, 2006 Report Share Posted May 3, 2006 Hi Ira My piece of wire is not much more than 6 inches. I have full control on the heat and set it so it cuts fast without too many fumes. I use the 1.25mm dia wire to give it strenght so it does not bend when in use. Cheers WEKA Quote Link to comment Share on other sites More sharing options...
Faran Posted May 3, 2006 Report Share Posted May 3, 2006 As I'm a bit of a neanderthal you'd probably find me with a knife and a coat hanger with a wood handle sitting next to a fire barrel to shape the poly. While I admire the ingenuity of it all, it's a lot of work for a one-time project. Anyone know if those little carbon face masks are enough to protect the lungs from poly fumes? That stuff stinks like nothing else. The neighbours sometimes chuck in poly and plastic when burning wood. Ugh. Quote Link to comment Share on other sites More sharing options...
WEKA Posted May 4, 2006 Report Share Posted May 4, 2006 I suggest you do what I did and sit outside in the breeze. Even with my temperature controlled system there were still enough fumes to do your lungs some serious harm - not worth the risk of trying to do it in a space without good ventilation WEKA Quote Link to comment Share on other sites More sharing options...
Ira Posted May 4, 2006 Report Share Posted May 4, 2006 Hmm, Most of the suggestions I've seen suggested using pretty low heat on the wire and making slow cuts. That way you get less overburn(Foam around the wire melted instead of just what's in contact with it) But I've been looking mroe for cutting out parts for RC planes and I'd imagine precision is a lot more important than speed. Quote Link to comment Share on other sites More sharing options...
2manytanks Posted August 26, 2006 Report Share Posted August 26, 2006 tried something similar but it did not turn out because i concreted the whole thing did a PH test after soaking it in water for a couple of days and could not get the PH back below 8 i carved out the cervices in the rock face by hand with a very sharp stanley Knife and didnt slip once (yeah me!!) i will be following this thread with great intrest to see how you get on. and see where i could do better next time i try Quote Link to comment Share on other sites More sharing options...
fishy_t Posted August 26, 2006 Author Report Share Posted August 26, 2006 Well done for trying! This is my attempt - my plans changed a bit but I'm happy with the results: The agae is just starting to grow so its starting to look better - the pH is 8.2 but thats what I want and I've got limestone in there anyway! Quote Link to comment Share on other sites More sharing options...
TM Posted August 26, 2006 Report Share Posted August 26, 2006 you can also use plaster of paris and make a mould at the beech on some rocks, then fill with concrete Quote Link to comment Share on other sites More sharing options...
malawi_man Posted August 26, 2006 Report Share Posted August 26, 2006 AWESOME! Quote Link to comment Share on other sites More sharing options...
ryanjury Posted August 26, 2006 Report Share Posted August 26, 2006 Yeah man it looks awesome Quote Link to comment Share on other sites More sharing options...
Tiden Posted August 26, 2006 Report Share Posted August 26, 2006 Soooooooooo have to agree with kk and ryanjury. That looks freak'n unreal man good effort :bounce: Fronts gotta love the room to grow. Quote Link to comment Share on other sites More sharing options...
ryanjury Posted August 26, 2006 Report Share Posted August 26, 2006 Yeah is there any more details on your tank? Im curious as to how big it is.. It looks like an intesting design being a corner tank and all.. Quote Link to comment Share on other sites More sharing options...
fishy_t Posted August 26, 2006 Author Report Share Posted August 26, 2006 Thanks guys! :oops: Just to warn you - if you are thinking of giving this sort of thing a try it is MUCH harder than you can possibly imagine and takes at least 3 times longer than you plan for!!! Yeah the fronts have plenty of room to grow! there are only 6 of them in there with my featherfin and they have 500l to live in! The tank is 1mx1m L shape, its 50cm wide and 75cm deep if that makes sence?! Thats why I wanted to make the rocks could stacking them wouldn't get very high and so it would look quite stupid in such a deep tank - although I'll have to give the fronts a new tank anyway when they grow up! Hope that answers any qeustions?! Quote Link to comment Share on other sites More sharing options...
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