Rockwall background

[Mogo]

Well, I pretty much finished carving out all the styrofoam, and was not happy with the results, somehow it just didn't look anything like a natural rock formation . I sat and thought about a better way about going about it and devised another plan. So off to the local hardware store I went.

Here is the thread with my initial attempt:

This didn't work

The first problem I ran into was the run of the mill white styrofoam would come off in chunks and I couldn't get the desired look. This time I picked up the extruded polysterene type, which is much stronger and denser. The reason why I had intially bought the regular white kind was because the extruded type was more than twice the price for the same size slab. Anyways, I found this stuff is much easier to work with.

In my initial plan I had cut out two sections on either side for my filter intake and heater. The problem I ran into with this was all the rocks along those edges ended up the same thickness and stacked up in a straight line. How natural is that? So this time, I just marked out where the heater and intake would eventually go, you can't see the markings in the photo, you'll have to excuse the quality as I'm using a cheap web cam (brother took back the digital for the time being)

 

[Mogo]

The biggest issue I had was the whole thing just didn't look right. Although I carved from top to bottom, no matter how hard I tried, I just couldn't get the "rocks" to look like they had naturally fallen onto each other. To solve this problem, I decided to actually carve the general shape and size of each rock from the excess foam board first (keeping in mind the base rocks need to be larger and thicker as I plan to hollow them out later and fill the cavities with cement to counteract the bouyancy of the styrofoam) I then siliconed the pieces and used wooded dowels to hold them in place.

The advantage of doing it this way is that it allows for better use of depth, angles, and it allows you to take chunks and let them kind of fall onto each other and see how they would naturally come together. Play around with different sizes and shapes until you get the look you want.

 

[Mogo]

Another advantage I've found, is this is much, much faster I've worked on it twice now, and this is how far I've gotten. Another thing I've found is that before I was trying to carve caves and tunnels into the styrofoam structure, and it just wasn't working. This way you can strategically place your rocks to form caves and tunnels. It's also easier to see how the three seperate pieces (like the original plan, to make it easier to fit into the tank, and to get around the crossbar on larger tanks) will fit together like a puzzle. Once the basic structure is complete, I will begin carving the details and shapes into the rocks

 

[KnuckleHead]

Sorry to tell you this Mogo but your going to have to make another one. Your going to have to make it FOR ME . Your project is looking great so far. I envy your imagination. One other thing, I thought I saw a pair of handcuffs under the bed .

 

[Ob1]

I like it - please keep posting inages - I.ve just glue a jewel background to my tank - Doh!!

 

[Mogo]

Yeah, sure KH, I'll make one for you for sure. I don't mind the extra practice. I'm sure once I get the thing in the tank, I'll see things I would do differently, and will probably end up making a few before I'm happy with one. As long as you're willing to pay for the supplies and shipping costs, and don't mind being patient Oh yeah, and for a picture of you riding your pink...wearing the pink...

Thanks Ob1, I will definately keep posting up my progress, which reminds me, I have some more updates.

 

[Mogo]

These are going to be long updates, but whatever, it's been an interesting experience.

The good thing is, I can finally take some better photos, I managed to steal my brothers digi cam back. The conditions we're not the greatest this time though. After having to have my car towed to the mechanics (locked brake cables I couldn't un-jam, or any of my big manly neighboors couldn't either), I had to drive 45 minutes away to not only pick up the camera, but also pick up my brother and drive him another 45 minutes away to water his girlfriends plants, who's away on vacation. Then I have to drive him home...and yes, it get's worse. Not only do I have to drop him off, but I have to help him drag the bulk supply of TP and paper towels my MOM bought him through the elevator and to his apartment. You would think a 30 year old man living on his own in the big city could buy his own toiletries? To top the whole situation off, I got stuck in rush hour traffic, and that 45 minute drive I did in the morning, now took me close to two hours!!!

Anyways....so here is the structure a couple days ago. The positioning of the styrofoam and glueing (siliconing) is all done. On to the next step...CARVING!!! Yay, finally on to the next step!

 

[freshmike]

Coming along great!!! Can't wait to see it when is finished!!!

 

[Mogo]

So I finally finish carving some general shapes to the rocks. At this point, detailing your rocks is not important, as that will be done in the cementing stage.
The important thing in this step is to give your rocks some nooks and crannies, remembering that you will be applying about an inch of cement on top, so make things slightly exaggerated. Another thing to keep in mind is the total length of your rockwall. You'll want to keep in mind the thickness of the cement, last thing you want is to finish it and not be able to fit it into the tank. I used a sanding bit on a Dremel and a small kitchen knife to carve into the structure. But please wear protective eye goggles and mask if using a powertool, as tiny bits of the foam go everywhere. It's a messy job. I know the spaces between the rocks look big now, but remember, these gaps are quite exaggerated in this phase. There are a few minor changes that will be made in the cementing process, and as you can see by the photo, I went a little crazy with the Dremel and ripped off a couple pieces, or wasn't happy with the look of a couple.

The next step is to heat the structure. This does shrink it a bit, but it makes it into a nice smooth surface. I tried using a high powered hair dryer, but it did nothing. Perhaps a hair dryer would work on the white non-extruded styrofoam, but it didn't work on this type. I did this step outside, wearing my googles, and one of those fume/chemical/paint mask things, and used a heat gun.

I'll be beginning the cementing tomorrow. I went yesterday to pick up some Portland Type 1 or Type 2 cement, only to discover it wasn't available anywhere, all the places I went to only had Type 10. I spoke to the head of the department in one of those big box type locations, not mentioning any names here. I asked him what the difference was, and asked if they carried anything comparable to the Type 1. His answer was no way, and that they could special order the Type 1 for me, but I would have to buy a minimum of one skid, which works out to 40 bags! He then proceeded to give me a couple locations names, one of which was their distributor that I could get it from. After spending some time searching for these companies on the internet and in the phone book to no avail, I phoned a few other places. This is where it gets funny. The man I ended up on the phone with, proved to be invaluable and a great help. By the way, for those Canadians who have done their research or spoken to people in the States about DIY rockwalls, Type 1 = Type 10, Type 2 = Type 20...etc....for some unkown reason, us silly Canadians decided to add a little zero at the end

After speaking to the gentleman on the phone for quite some time, I was recommended Sakrete or Quikrete Sand mixes. These are premixed bags of Portland cement and sand, and all you need to add is water. I will not go into all the reasons here why he recommended these, but I went to a local hardware store and picked up the Sakrete Sand Mix this afternoon. I also picked up a mixing bucket and 5 of the cheapest paint brushes I could find. Gloves would be something else to pick up if you don't have any usable ones lying around...

To be continued....

 

[freshmike]

That looks awesome!!!!!!

 

[Mogo]

Thanks Mike I can't wait to start cementing the whole thing. I'll get some more pics up as soon as I get some more work done on it.

 

[Lithril]

Gotta say its looking absolutely amazing. Won't styofoam decompose? And isn't cement partly limestone which will effect water parameters. Actually bugger the water parameters I want to see the final product...

 

[Mogo]

Hi Lithril,

No I don't think the styrofoam will decompose. Styrofoam repels water, and from what I've found out from my research, it should be okay. As for the cement issue, yeah it will raise the pH in the first few weeks or so. When the cement is all nice and cured, I will be soaking it in the tub for about 6 weeks, changing the water out every day or two. The tank this is going into is maintained at a pH of 8.1, so it will be okay. I don't know what the lowest pH will be with the cement (I read somewhere where someone soaked it for 8 weeks and the water went back down to a pH of 7.6) but I am going to make a small test piece that I can leave in a bucket for even longer to see if the water will eventually drop back to the original pH of the tap water. Wait till I reveal what I am going to use to colour my rocks

 

[Mogo]

Well, I managed to get the next step done on two of the three sections. Using advice I read on other peoples projects, I made the first coat of cement quite runny and used a paint brush to apply it. This will apply a very thin layer of the cement, and is supposed to help the next layer "stick". One thing I wish I had done was buy a smaller brush. I bought a bag of five cheap brushes, but all of them were two inches and it was kind of difficult to apply the cement into my caves. Oh yeah, before you begin this step make sure to measure, and measure again, making sure you leave tolerance for the thickness of the cement. And enough tolerance for your hardware.

I didn't coat the back or bottom yet at this point, as I want to see if I'll need to make cavities in the base rocks or back of some of the other rocks and fill them with cement. I don't want to silicone the structure into the tank, which I've read other people have done, so I'll need to figure out how much cement will be enough to compensate for the bouyancy of the foam, to keep the whole thing down. Well, here it is....I hope I've covered everything, any questions, just ask

Oh yeah, and that's my sig other being a big goof

 

[Mogo]

Oh, yeah, I forgot to mention, the pic was taken after letting the cement dry for about 24 hours. I've now started the next step on one of my sections. I've left the third section still styro pink, and will begin to work on cementing it when I've completed the other two sections. I'm doing this just incase my cement is a little thicker than I've allowed for. This way, I'll be able to cut it a little smaller so the thing will fit properly into the tank. I think I've left enough clearance, but better to be safe than sorry.

Now this part is really fun. You'll have to play around with the consistancy of the cement to get it to we're it's easy to work with. I found that a nice soupy mixture works the best. I wore gloves and spread it around with my hands. I got most of it done with it laying flat on it's back, and will reach other area's after letting it set for a couple hours. The thickness of this coat is about 1/4 inch. Once again, I've left the back and bottom as is. One more coat will be going on top when I've let it sit for 24 hours.