Insane Reefer
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With limestone grit, you get the calcium carbonate, but limestone also has a tendency to go crystalline - the miners aren't too picky, and so some (20%) will be the shiny stuff.
The Ultimate DIY Rocks!
- Thread starter JohnL
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Neptune777
Premium Member
Filler?
Has anyone considered using small polystyrene beads as filler to create volume and air pockets in the concrete (same stuff used to fill bean bag chairs).......They are very cheap and most fabric supply places carry them...
http://www.beanbagbeads.com/images/MS01-lg.jpg
Has anyone considered using small polystyrene beads as filler to create volume and air pockets in the concrete (same stuff used to fill bean bag chairs).......They are very cheap and most fabric supply places carry them...
http://www.beanbagbeads.com/images/MS01-lg.jpg
Neptune777
Premium Member
Here is a good example of what polystyrene beads and portland cement look like when mixed together. Looks like you can make your rocks really light (or even float 
) depending what ratio you use. Looks like they would be very porous too.....
http://www.simprolit.ru/images/mat1big.jpg
) depending what ratio you use. Looks like they would be very porous too.....http://www.simprolit.ru/images/mat1big.jpg
Neptune777
Premium Member
I am assuming these polystyrene beads are reef safe since eggcrate is made of the same material.....
BOKER420
Premium Member
well here she is. My best piece yet I think. It looks pretty close to real rock. If you look at the right angle it looks like a dog.
Using the salt right up against the concrete to mold it leaves a really nice looking surface.
This rock weighs around 40lbs I would guess but there is almost half of a 5 gallon bucket worth of salt mixed it. I used about 1.75 parts salt and to make sure it was strong enough I added 1.5 parts cement.
Using the salt right up against the concrete to mold it leaves a really nice looking surface.
This rock weighs around 40lbs I would guess but there is almost half of a 5 gallon bucket worth of salt mixed it. I used about 1.75 parts salt and to make sure it was strong enough I added 1.5 parts cement.
Neptune777
Premium Member
<a href=showthread.php?s=&postid=10104221#post10104221 target=_blank>Originally posted</a> by sunkool
here are my pics from my latest batch
The first three are right out of the mold
The last is after a 1 hout soak to get the surface salt out to see texture.
Looks fantastic! What are your ingredients if you don't mind me asking....?
sunkool
New member
1 part wpc
5 parts sand
4 parts salt (blue bag)
I mix the wpc, sand and 1/2 the salt with a tile grout mixer (best $10 I ever spent) add water, mix adding a little water at a time until it is like cottage cheese. Then add the remander of the salt.
Mixing in 1/2 the salt at the start helps make smaller pores.
then just take small fingertip globs and stack them on top of each other adding big holes.
5 parts sand
4 parts salt (blue bag)
I mix the wpc, sand and 1/2 the salt with a tile grout mixer (best $10 I ever spent) add water, mix adding a little water at a time until it is like cottage cheese. Then add the remander of the salt.
Mixing in 1/2 the salt at the start helps make smaller pores.
then just take small fingertip globs and stack them on top of each other adding big holes.
Sunkool. good job! your rock looks the closest I have seen to the real thing. Are the rocks strong enough with that little amount of cement. Do you have any pics of your mixture wet right before you add the remander of the salt? I like the idea fo disolving some of the salt to create different size holes.
sunkool
New member
yes it is strong won't hold up a house but stacked up 2' high it won't break. I droped one moving it from about 3' high on the driveway and it didnt break. came out much stronger than just pc and salt.
on a side note I had a dry cured one made the same way and soaked it overnight and took it out of the water and it is double the weight. must be porous.
on a side note I had a dry cured one made the same way and soaked it overnight and took it out of the water and it is double the weight. must be porous.
Rhodophyta
New member
Whhh! Somebody is going to think of combining the polystyrene beed rock with the baking method of curing. Would the plastic melt and run out or burn???:smokin:
Insane Reefer
New member
Neptune, you can use those beads, or Styrofoam peanuts, if you want - either are considered safe, but why add them? Salt works well enough for making the rock lighter and also gives it nice voids...
I like your piece - it should be really stable and will look nice when covered with corals
You really shouldn't have too much trouble releasing the salt - you worked in layers, and most places aren't too thick. But IME, the salt is a lot harder to release in the sand/salt only mixes, so you will really want to think about hot water...
I love white cement, to my eye it looks so much nicer
It also colors nicely with colorant.
Sunkool Nice work! Looks like you are using a silica based sand? Or did you get lucky and find some nice white limestone/carbonate?
Oh, keep in mind that the prices I quoted you were for "Ol' Skool+" rock - not just cement/sand rock - Ol' Skool+ costs a Lot more per pound to produce - though you are going to tear through the salt with that ratio you are using. Have you noticed the almost "porcelain" quality of the white? Some of my experiment pieces with sand/salt only and wpc almost chimed when you flicked them with your finger...
I like your piece - it should be really stable and will look nice when covered with corals
You really shouldn't have too much trouble releasing the salt - you worked in layers, and most places aren't too thick. But IME, the salt is a lot harder to release in the sand/salt only mixes, so you will really want to think about hot water...
I love white cement, to my eye it looks so much nicer
It also colors nicely with colorant.
Sunkool Nice work! Looks like you are using a silica based sand? Or did you get lucky and find some nice white limestone/carbonate?
Oh, keep in mind that the prices I quoted you were for "Ol' Skool+" rock - not just cement/sand rock - Ol' Skool+ costs a Lot more per pound to produce - though you are going to tear through the salt with that ratio you are using. Have you noticed the almost "porcelain" quality of the white? Some of my experiment pieces with sand/salt only and wpc almost chimed when you flicked them with your finger...
Insane Reefer
New member
I think after this next batch of tests I need to split off from this thread with a new "Jiffy Rock" thread. Starting to get some confusion and don't need any more of that, lol
Insane Reefer
New member
Try letting some of your salt sit in hot water for a while. Allowing the salt to "melt" into the cement isn't a good thing for the cement, really. If you want different sized grains, just think ahead and allow them to shrink outside the cement...
JMTC
Insane Reefer
New member
It would certainly burn, and release toxic fumes. This would be a really bad idea - not that anyone here would be that stupid, right kids?
Rhodophyta
New member
No, that's earlier in the thread. I only thought it's a matter of time before the two come together like others things have here.
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