So ive been wanting to build some rockwork and heard bout a few types of cement found in home depot. Any updated ideas or issues from anyone who has used these types
-
Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
Cement
- Thread starter Ruth C Lewis
- Start date
1) Most of the Cement available, is Portland Cement. It refers to the manufacturing process. Since most cement around is Portland, it really is not necessary to use the term.
2) All Portland cement is hydraulic cement. There is no such thing as a specific "hydraulic" cement. That is a marketing hype, or at the very best a misleading and erroneous sell point. Cement setting is a hydration reaction. Water chemically bonds with the cement slurry to form first a gel and then a solid. Extra water actually speeds it up (and makes it weaker.) Hence "Hydraulic." Cements used when water contamination is expected generally will be blended differently by adding more silica. Don't waste energy looking around for "hydraulic" cement: it is staring "you" in the face sitting on all the shelves at HD.
3) Portland Cement is alkaline, not acidic. Alkaline is the opposite of acidic, e.g. basic (Base—high pH as opposed to Acid—low pH.) This is the problem with most cements that folks recommend, as "Portland Cement," which is a meaningless term. It is the alkali in the Cement that creates the need to "pH stabilize" or "Cure," (a bad misnomer) to lower the pH, before the rock can be used in a Marine aquarium.
4) White cement is a specific type of "Portland" "Hydraulic" cement. You don't usually find it sitting on the shelf at Home Depot, hence this part of the recipe is generally left out, in favor of misused terms, and Portland and Hydraulic get tossed around...
5) Well... enough already. What do I use, and where do I get it? You don't get it at Home Depot, or any other big box store. Probably not likely at any smaller hardware chain either.
What you want to use is a (Portland) White Cement, Low Alkali type. It is used for finish plastering swimming pools (other uses as well.) You get it at establishments that specialize in swimming pool building supplies. Riverside makes such a cement.
I have used a product called Stone Fix by Aquaforest. I have connected heavy rocks to create an overhang with it. It is solid. You have to mix it in small batches and don't make it watery.
2) All Portland cement is hydraulic cement. There is no such thing as a specific "hydraulic" cement. That is a marketing hype, or at the very best a misleading and erroneous sell point. Cement setting is a hydration reaction. Water chemically bonds with the cement slurry to form first a gel and then a solid. Extra water actually speeds it up (and makes it weaker.) Hence "Hydraulic." Cements used when water contamination is expected generally will be blended differently by adding more silica. Don't waste energy looking around for "hydraulic" cement: it is staring "you" in the face sitting on all the shelves at HD.
3) Portland Cement is alkaline, not acidic. Alkaline is the opposite of acidic, e.g. basic (Base—high pH as opposed to Acid—low pH.) This is the problem with most cements that folks recommend, as "Portland Cement," which is a meaningless term. It is the alkali in the Cement that creates the need to "pH stabilize" or "Cure," (a bad misnomer) to lower the pH, before the rock can be used in a Marine aquarium.
4) White cement is a specific type of "Portland" "Hydraulic" cement. You don't usually find it sitting on the shelf at Home Depot, hence this part of the recipe is generally left out, in favor of misused terms, and Portland and Hydraulic get tossed around...
5) Well... enough already. What do I use, and where do I get it? You don't get it at Home Depot, or any other big box store. Probably not likely at any smaller hardware chain either.
What you want to use is a (Portland) White Cement, Low Alkali type. It is used for finish plastering swimming pools (other uses as well.) You get it at establishments that specialize in swimming pool building supplies. Riverside makes such a cement.
I have used a product called Stone Fix by Aquaforest. I have connected heavy rocks to create an overhang with it. It is solid. You have to mix it in small batches and don't make it watery.
Composition of Cement
There are eight major ingredients of cement. The general percentage of these ingredients in cement is given below:
Ingredient
Percentage in cement
Lime 60-65
Silica 17-25
Alumina 3-8
Magnesia 1-3
Iron oxide 0.5-6
Calcium Sulfate 0.1-0.5
Sulfur Trioxide 1-3
Alkaline 0-1
Caution:
Sulfur Trioxide: Chemical formula is SO3.
Should not be present more than 2%.
Excess Sulfur Trioxide causes cement to unsound.
Alkaline:
Should not be present more than 1%.
Excess Alkaline matter causes efflorescence.
hydraulic cement (marketing) Its ability to expand making it useful for anchoring, plugging holes and filling gaps to stop water. cement cant do.
I would take Diana Suggestion on Stone Fix by Aquaforest or any other company that works with Reef an Fish safe products
There are eight major ingredients of cement. The general percentage of these ingredients in cement is given below:
Ingredient
Percentage in cement
Lime 60-65
Silica 17-25
Alumina 3-8
Magnesia 1-3
Iron oxide 0.5-6
Calcium Sulfate 0.1-0.5
Sulfur Trioxide 1-3
Alkaline 0-1
Caution:
Sulfur Trioxide: Chemical formula is SO3.
Should not be present more than 2%.
Excess Sulfur Trioxide causes cement to unsound.
Alkaline:
Should not be present more than 1%.
Excess Alkaline matter causes efflorescence.
hydraulic cement (marketing) Its ability to expand making it useful for anchoring, plugging holes and filling gaps to stop water. cement cant do.
I would take Diana Suggestion on Stone Fix by Aquaforest or any other company that works with Reef an Fish safe products
What's the difference between concrete and cement
concrete has stone
So if I take cement and mix stone that then turns the cement into concrete. ? Also the man made live rock you see from suppliers it's usually slight coraline in coral is that a type of concrete?
Stone, gravel makes cement into concrete , as far as man made live rock I would just call it culture stone. I personally would go with a Reputable supplier and get some rock less concern of leeching undesirable chemicals into the system
Wow. Lots of stuff learned! Thank you for all the information. Im only doing small rock aquascaping so i can mix small amounts at a time. And i will try to find stone mix around here. Another question is after i finish how long before i can put it in the tank?
It all depends on the product you use, the Stone Fix by Aquaforest is a bonding agent for Live rock pcs. you will have to research to find the right compounds if you are going to make your own rock, as for as cement it takes years to cure and always a chance of leeching
Thats what im doing im using small lr, and building a unique shape i hope if it works out, so no heavy pieces
With the Stone Fix you would mix a small amount. It is better if the rock is dry in the area you are join together. You can link together when wet but dry is better. It takes about 15 minute for the bonding to occur. Just make sure when mixing the powder with water that it mixes into a very glue consistency. Don't use too much water or it will not bond.