DIY Rock Tutorial/Info Thread (Rocks, walls, floors, etc.)

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Joining a new forum is kinda like starting fresh for me, and I definitely love to contribute when I can. I've casually scanned the threads in this area and haven't seen much in the way of DIY rocks and rock projects.

Since making DIY rock is my business, I'd like to think of myself as somewhat well-knowing of the subject. I've definitely tried a whole lotta methods, ingredients, and have failed many, many times before I got to where I am today. I am constantly learning new things and am always open minded to new ideas.

Why am I doing this if this is my business? Truth be told making rock takes a lot of time (Major patience), learning, skill, sometimes luck, and more... if you want it done right. Most people (My clients' customers.. I am a wholesaler) would rather just buy the rock than make it themselves... and it makes sense for most people. Some people have an advantage of having certain equipment and/or background to make rock well and at a low cost... most others do not. Plus it ain't like I'll be giving ALL my secrets away! ;)

I am going to write a tutorial about rock making (Including rock walls, floors, etc.).. a process that will take time as I'd like to be as thorough as possible, not to mention get people's opinions/experiences. At the end I will combine all info into a longer, more complete post and I'll post a newer version as time goes by, should it be needed.

Each new post that I write will be like a chapter and my current outline will be the following:

1. Materials, ingredients, and tools
2. Recipes and casting material
3. Temperature requirements, mixing methods and requirements, water amounts, and hydration
4. "Curing"
5. "Kuring"
6. Results (In aquarium water)


I should also mention I will be talking strictly about DIY rocks... I have no training or experience in things like foam projects. Look forward to having the first chapter out by tomorrow night. Don't be shy to ask questions and/or post your experiences and opinions! :D
 
Last edited:

revhtree

Owner Administrator
View Badges
Joined
May 8, 2006
Messages
47,602
Reaction score
85,989
Rating - 100%
1   0   0
Oh yea! Can't wait for this thread! :)
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
1. Materials, ingredients, and tools

Being prepared: Being prepared is the best thing anyone can do before undergoing a project.. especially when it comes to something time-based like rock making. Before starting you have to make sure everything is ready to go, and is reachable. Once you start making rocks it sucks when your hands are goopy and you need to reach for a forgotten tool in a delicate part of the house!

Materials, ingredients, and tools:

DSCN5216Medium.jpg


Let's start with tools:

- Rubber gloves: I am not talking about medical gloves here, no no. We're talking about dishwashing gloves, thick but not thick enough to make you feel like a 50's robot motion-wise. This may be the best buy in the whole project.. you use your hands everyday and it's a very nerve-rich part of the body. Cement will eat your hands away and the pain from those "burns" are excruciating. I used the "dipped" gloves for extra protection. I advise this especially if you ARE NOT using perlite but something gravel-like (Dolomite comes to mind)! More on this later.

- 5G Bucket: Just about every reefer's favorite friend. This is great to use for dry mixing the ingredients together before the water addition.

- Handheld Dispenser: Something to keep your ingredients measured as you prepare your dry mix.

- Cement bin: These are common and found at places like Home Depot and/or Lowes, and are pretty cheap. I promnise you this is a worthwhile buy! It makes mixing a ton easier by keeping the mess inside the shallow bin, plus the rounded bottom makes it easier to scrape out ALL usable mix.

- Plastic watering can: This is a surprise to the uninitiated. Why not use a hose? Well you can, but I highly recommend using one that has a shower-type head. You want major control over the water, but it really helps if the water is spread out instead of a forceful beam. A watering can is helpful in that is gives you both the control and spread of water.

- Water: This is a "no, duh" component in the cement creation world, but people have asked about what type of water. I just want to say it, tap water is just fine to use.

- Casting box: Depending on how you plan on casting, the needs change. For example, a lot of people use sand as a casting material... so you would want a semi-sturdy box filled with sand, and some water nearby to form it with. I personally use other pre-made rocks as my casting material. My life is a little easier as I just let nature form the rocks for me.. and I don't need a box or anything. I just stack rocks on the floor and pour my mix onto it... easy-peesy.

- Suit of armor: I keed, I keed. But remember that cement can eat through your skin and the process of rock making ain't exactly dainty. Either wear an apron (Lowes/HD has them for like 3 bucks) or wear your "work clothes" that you don't care about.

- Mask and Eyewear: This is one of those that people get warned about but don't actually follow. If you want a good reason to wear this stuff, think of the cement like kalkwasser. The cement dust that flies into the air will enter your eyes and lungs. Getting, what I call, cement-lung absolutely sucks. You cough a bunch, and everything tastes like cement. Y'all prob know what eye irritation feels like.. it isn't fun either.

- Washing bin: This is another overlooked tool. Take any ol' bin and fill it partially with water. After you finish casting whichever piece of rock you are doing, you use the bin to get the residual mix off of your gloves. It's helpful because when you go to dry mix a new batch of mix, having wet mix already on your hands just messes things up. You also want to do this, then dry your hands in an effort to keep the dry cement away from moisture.

DSCN5217Medium.jpg



Ingredients (Aggregates): An aggregate is something you mix into cement to create concrete/mortar. It ranges to many, many things like sand, pebbles, etc.

- Cement: There are many types of cement out there. I personally use good ol' portland (Type l/ll). The normal grey stuff is widely available. The white is not so easily found, but it's my choice of cement as most reefers who buy rock want it to look like the base rock that's typically sold out there. You make what the customers wants. ;)

If you're making rocks for yourself and don't mind the grey, especially if you plan on having a full reef to cover up the grey (Corals, corraline, etc.), I would definitely use it as it's cheaper... waaaaay cheaper.

- Sand: This aggregate is pretty crucial in the making of rocks. This isn't to say you can't make rock without it, I just wouldn't suggest it. Sand is easy to get and isn't very expensive (Depends on which you use). It's a great "fine" aggregate that goes along well with "coarse" aggregate.


- Aragonite Sand: This is the most expensive of the sands, yet it is also the most favored. It comes in many names like calcium sand, etc but is not widely used outside of this hobby. I use this but as a business I can get it at a decent price because I buy it in bulk. Obviously this is not possible for most hobbyists, and they are given the choice between buying retail aragonite or choosing another type of sand at a much cheaper price.

DSCN5219Medium.jpg


- Quartz Sand: If anything in the DIY rock world gets a lot of attention it's the debate about using quartz sand. It is one of the most misunderstood things out there because of it's relation to silica (This sand is also called Silica sand). You can judge for yourself, but in my honest opinion I see no problems using this sand. If you want some proof look no further than one of reefings authority on reef chemistry: Randy Holmes-Farley. Craig Bingman also wrote on this subject as well.

The issue with quartz sand is not the silicates it releases into the water, it's the "other" stuff that comprises of the sand. You see most quartz sand bags will typically be about 98% quartz, while the other 2% is unknown. A good way of thinking about this is the fact that quartz is white in nature, the bags you get from HD/Lowes is more brownish. The brownish tint is caused by that other 2%.

So should you choose to use quartz sand, try to find the whitest bag possible and give it a washout, to try and rid of that 2% (Most cases it mostly comprised of dust). While you don't get the pH/calcium depositing effects like you would from aragonite sand.. it's not that big of a difference.


- Crushed Coral: This is another aragonite type situation. It is fantastic to use but is expensive. It helps with making the rock look more natural, but there are other cheaper ways of doing so. Still if you happen to have a bunch or can get it cheap, it's a great aggregate to use.


- Crushed Oyster Shell: This product does receieve a lot of attention because of the debate that runs about it on whether it leeches out phosphates or not. From my readings (brief, as I don't personally use it) it seems this is true. For some people it works just fine and have no problems with it, but others will swear up and down it is the cause for their high phosphates. Unfortunately this is something you, as the rock maker, will have to decide for yourself. This decision is harder still for those that live in rural areas... you can find this stuff pretty cheaply at feed stores.


- Perlite: Ah now we've hit upon a favorite of mine. I love using this stuff because it is REALLY lightweight, and is pretty inert. What is it? It's basically puffed glass.The problem with perlite is that it's not exactly cheap. Like aragonite, it's an expensive aggregate. Aside from it being light-weight and inert, it's also easy on the gloves and hands when creating the wet mix.

DSCN5218Medium.jpg


- Salt: Yet another foundation for debate in the DIY rocks world. In my personal opinion I DO NOT recommend using this aggregate. You can get the neat texture created by salt using other methods. While salt may have worked (currently) for others, for most it will cause your rock to fail prematurely. In short, salt retards the "curing" process of the rocks. By the time your rock is done "curing" it's more brittle than rock without salt and eventually will break apart. Again, there are people who will tell you they've had plenty success with this, but from my experience, and from other professionals', salt is just better left out.
 
Last edited:
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Chapter 2

2. Recipes and casting material

This is going to be a shorty.

Recipes:

There is an absolute stock pile of recipes out there it's enough to make any novice's head spin. The problem isn't that the high number of recipes are bad or

anything, but it's confusing to dicern which is right for you. Let's get some basics out of the way:

- In general we want about 3-5 parts of aggregate to 1 part of cement. I personally prefer 4 parts.. it just works for me. The trick is to remember what the cement's purpose is: glue. Cement is the glue that binds the aggregates together. Cement is NOT the body of the rock.

- Your rock will take on the charcteristics of your aggregates. For instance if you use aragonite sand, the rock will act like a giant grain of sand... it will leech out some calcium and act ever so slightly as a buffer. You use perlite? Your rock will be lighter. How about dolomite gravel? Your rock will be more solid. The list goes on and on.

- Also when portioning your ingredients, keep texture in mind. You don't want to use mostly sand as your aggregate, it smoothes out the surface of the rock. You don't want too much coarse aggregate as too many spaces between the rocks makes it less held together.

Recipes: Here are some recipes I've used

1 Cement : 1.5 Dolomite : 1.5 Aragonite

1 Cement : 2 Dolomite : 2 Aragonite

1 Cement : 1.5 Perlite : 1.5 Aragonite

1 Cement : 2 Perlite : 2 Aragonite

1 Cement : 2 Perlite : 1.5 Aragonite

1 Cement: 1 Perlite : 1 Dolomite : 1 Aragonite

And on, and on... you get the idea. All of the above works fine.. only subtle changes were noted amongst the different recipes. Your imagination is the only limit. I highly recommend you experiment with recipes and ingredients to achieve your personal favorite. Lord knows I sure have! ;)

DSCN4727-1.jpg

This picture is of my earlier work before using perlite.

Casting Material:

- Sand: Works fine but you'll need to prepare the mold before you cast it. Dampen the sand with some water and shape out a rough draft in the sand of what you want your piece of rock to look like. You'll need a box to hold the sand in.

- Rock: If you have scrap rock laying around put it to work! This is my favorite method for making rock. I get random shapes and sizes that rock is supposed to look like. The one con to this method is that you'll have to chip out the mold rock from the casted piece. You don't need a box for this method.

- Foam and plastic: I've tried all sorts of other things. This method is me foaming, at random, a flat board, then putting plastic over it. Casting is simple.. just pour the mix on it. No pre-dampening of anything is needed.. a slight bonus.
 
Last edited:
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Chapter 3

Temperature requirements, water amounts, mixing methods and requirements, and hydration

This is one of the most important posts in this rock making thread (Of course this is just my opinion).


Temperature requirement: There's a temp requirement when mixing cement? Yes there is! You might have noticed that cement workers don't do cement work during the winter unless the environment is managed warmer somehow. The lowest temperature you should be mixing cement at is about 50F. The issue is that when cement hardens, it does so continuously for years and years. In typical conditions cement will get most of it's strength in about 28 days. The colder the environment surrounding new cement, the slower it's strengthing process. The warmer.. the quicker.. to a point.

Obviously we want the best for our rocks, and I suggest mixing at a comfortable temp of about room temperature up to whatever your comfortable being at, heat-wise. You'll be far more uncomfortable in increasing heat before cement does.


Water amounts: This is CRUCIAL and takes quite a bit of practice. You WILL screw up the first few times unless you are one lucky person. What's a bit tricky about how much water to use is that it isn't something you can exactly measure accurately. Just because you have exact measurements in your recipe doesn't mean the same amount of water will kick the cement just right everytime. It's an annoying problem... but it's just a hurdle that needs to be overcome.

What needs to be learned is adding water and realizing when enough is enough BEFORE you pour the last drop. It sounds odd, but cement is slower than our thought process. It first takes in the water, as you mix it, thinks about reacting with it, then decides it's enough to kick it into gear. Always be suspicious of the cement... it is out to mess with your head and deceive you... always.


Mixing methods and requirements: There aren't exactly many methods to mix cement, I mean all we do is just mix up a batch, but some basics should be known about. First comes dry-mixing, then wet mixing.

Dry mixing: I advocate dry mixing your ingredients before adding water. Using a 5G bucket, add your ingredients in no particular order but remember that you won't be making your rocks in one mixing. I often mix what equates to about 9-10 pounds of rock per mix. This amount is good for me because I don't feel rushed when casting, giving me time to give better detail to the rocks.

Once you get your dry ingredients in the bucket, pour them out into your cement mixing bin. From there, mix the dry ingredients like crazy till you feel it sufficient. After mixing flatten out the dry mix to the floor of the cement bin.. nothing tight or anything just a level field is fine.

Wet mixing: Now comes the hard part. Right off the bat you should know you will not be adding the water all at once. You will probably have to pour out some water at least 3 or 4 times to evenly distribute it and give you some warning as to the state of the wet mix. You're gunna pour out some water, evenly over the mix, mix like crazy, and then repeat. There is no way to explain this without showing it live, but eventually you'll "know" when the mix is ready. It's going to feel and look like semi-dry porage.

Not that this helps much.. but here is newly casted wet mix:

DSCN5208Medium.jpg


Like I said.. this is going to take practice. Don't expect to get this right the first, second, or third time. If you screw up and add too much water, just add another batch mix and you'll end up with double the wet mix.. but a second chance to get it right. Once you get it right.. off you go to cast!


Hydration: Here is way more info than you probably wanted to know about hydration. In short, hydration is the reaction of water and cement. The long version:

Cement hydration
 

revhtree

Owner Administrator
View Badges
Joined
May 8, 2006
Messages
47,602
Reaction score
85,989
Rating - 100%
1   0   0
Very cool thread! I am sticking it!
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Thanks Rev, I look forward to finishing this up, getting some additions from the other players out here and then completing the manual. ;)
 

Paul_N

MOD
View Badges
Joined
Jun 16, 2008
Messages
3,964
Reaction score
64
Location
Pittsburgh, Pennsylvania
Rating - 0%
0   0   0
How well does this mold around an object? If I wanted to make it less dense and put say a plastic wiffle ball inside it for places for little critters to go or maybe arrange some PVC pipe into a pseudo branch and then mold this around it do you think it would hold or more likely crack? I was thinking if I made it thick enough it would hold together.
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Depends on how big of a branch-like tunnel you want to make. Right off the bat I would suggest "rebar" for a hollow construction. More on that in a second.

I have stuck PVC pipe into rocks while molding and didn't have an issue, so long as the holes weren't numerous to weaken the overall structure. My only problem with using something so perfectly round is just how unnatural it looks... it's literally a perfect hole. This can be somewhat remedied by making the ends of the holes not so round.. giving the appearance that the rest of the tunnel is the same.

The good thing about using PVC is that you can let the rock harden (24 hours or less) and it's still fairly easy to yank out of the rock. Some rock makers just leave it in the rock, and you can be creative if you do this. Heat up the PVC pipe, bend it all around, and just leave it fully covered in the mix.

You'll find people in support or not in support of the idea of keeping PVC under saltwater, but I have yet to have a problem with this issue.

For branches it's suggested to use supportive and rigid aggregate (The rebar I spoke of), in addition to the other ingredients. Acrylic chips or fiberglass threads (Fiber mesh) are usually choice for this rebar application. The only bad part is that unless you know someone or a company willing to give this "waste" product.. it's actually a bit expensive.

But let's say you want to build a semi-large tunnel or even column? You could use something like eggcrate for this project. Cut some pieces of eggcrate and make it as round as you like (The less pieces the more square, the more pieces the more round). Remember that you need to leave out juts of eggcrate for the cement to hold onto. eggcrate alone won't hold on very well on it's own. Having a "spiky column" will make your life a lot easier.

Once you zip tie the pieces into a tunnel-like shape, you get the wet mix ready and cast on the outside. Voila, a nice large column or tunnel that's hollow yet decently strong.

Out of sheer coincidence I will be making this very thing for my upcoming tank overhaul. I've already casted the rockwall (You got a glimpse in one of the above pictures), but I am hoping to soon cast the "leaning" column soon. I'll definitely post pictures of both the rock wall and column project as soon as I finish them (Hoping they'll be ready by late December-early January).

HTH
 
Last edited:

Phatboy

Community Member
View Badges
Joined
Aug 9, 2009
Messages
72
Reaction score
2
Rating - 0%
0   0   0
Nice writeup...let me know that I need to pick an aggregate. Which at this time I still dunno what Im going to use.
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Thanks, I still gots more to go, but hopefully I'll have the rest of it done this week. :)

Whatcha lookin' at making? Rocks, rock wall, rock floor...?
 

Paul_N

MOD
View Badges
Joined
Jun 16, 2008
Messages
3,964
Reaction score
64
Location
Pittsburgh, Pennsylvania
Rating - 0%
0   0   0
Electrobes,
Thanks. It definitely helps. My intention was to leave in place any pvc or plastic I placed inside the rock. I would definitely try to make any visible holes look natural as possible.
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Hey Harry - I haven't been able to get the rest of the manual done just yet. I am out of the state briefly, but will be back soon.

Short summary: You want to cure rock for about 28 days. Typically concrete will reach its near-full strength by then. If you can, put the rock in a hot and humid environment for those 28 days, for the best results.

You then need to Kure them in water.. and depending how closely you followed the instructions for the cure process, it shouldn't be long before you can use the rock.
 
OP
OP
Electrobes

Electrobes

Valuable Member
View Badges
Joined
Jul 16, 2009
Messages
2,089
Reaction score
255
Location
Fort Myers, FL
Rating - 0%
0   0   0
Chapter 4

The Cure

This is a crucial, but mostly mis-followed step in the creation of our man-made rocks. I say this because this is the step where patience is most necessitated but often overlooked. The good news? It's a fairly simple step to follow.. up to this point, you've already done the hard part!

What do I mean... "Cure"? Cure is a term, meaning the rocks are undergoing chemical reactions, and the one we're most concerned about is hydrolysis, as mentioned earlier.

When cement workers do their thing, they follow very similar steps, in fact we use the very same things they employ... it all came from them. After cement workers cast their piece, you'll sometimes notice that there is a damp cloth covering it. You can add too little and too much water, but a damp cloth seems to do just about right for water dispersion. But since we're making rocks.. transportable pieces, we can take it a step further with little difficulty.

What the rocks would love is to be in a hot and humid environment. By adding heat and humidity you help out the hydrolysis process, increasing the strength and in effect, shortening the Kure process. There are any number of ways to achieve this, but the common practice is to just leave the rocks in a plastic bag, spray some water in it, close it off, and leave under the sun. In winter, you can do this by keeping the bag inside the house but by a window.

You really need to have patience and just leave the rocks in the cure process for the full 28 days. Every now and then, remember to re-spray the inside of the bag, with water, to keep the humidity up.

That's it... tough isn't it? ; )
 

A worm with high fashion and practical utility: Have you ever kept feather dusters in your reef aquarium?

  • I currently have feather dusters in my tank.

    Votes: 64 36.8%
  • Not currently, but I have had feather dusters in my tank in the past.

    Votes: 59 33.9%
  • I have not had feather dusters, but I hope to in the future.

    Votes: 25 14.4%
  • I have no plans to have feather dusters in my tank.

    Votes: 26 14.9%
  • Other.

    Votes: 0 0.0%
Back
Top