making bulk live rock

scarr105

scarr105

Member
Originally Posted by shiby1510
Well first I would like to say thanks for a little bit of encouragement Andretti... I feel quite discouraged... and no one was helping... so here we go
1. I picked up some tropical play sand (made by oldcastle)
2. This time i poured sand into 3 different boxes varying in size and shape.
3. I then formed my molds (the sand was already moist and cold so i didnt add any more water for the moldings.
4. I mixed my cement... quikrete portland I (I cannot find oyster shells around here for some reason... even a site i found that advertised them said that they only carry crushed calcium now... anyways.. so I started off the mix with 5 cups of trop. sand with 2 cups of cement.. cuz last time I tried 5 : 1 and that didn't go well at all...I then added water.. I think it was 2 cups.... I then broke up a couple hand fulls of spaghetti and cut up about a hand full of straws)
5. I then mixed it all up and as I was mixing added in more cement sand and some water... all here and there.
6. Once I felt like I had a pretty good mix I took my hand shovel that I used for mixing and put the mix in the molds.
7. I then sprinkled some carib. arag. sand from a reef.. to give some more texture just on the top.
8. I finally covered with sand.
9. I let it sit with the lids on for 2 days (it was around 80 degrees both days)
After the 2 days i brushed some sand around the top and touched it with my finger and the cement was still not dry.
I then took the lids off for a day and it was a little drier and still not done
I put the lids back on for another day...(cuz im not sure if u should keep lids on or off..when the lids were on the sand was cold and moist)
therefore I kept the molds in for a total of 4 days...
They felt semi hard but as soon as i dug them off the broke... not in crumbles but the broke apart...
I'm not sure what it is... maybe the cement is just crappy.. cuz its quikrete?? I just bought it so its not like ive had it sitting around the garage for years.
Or maybe when I was mixing all the stuff.. I took too long???
I am soo sad right now... cuz i don't know what to do... Ive read all the threads on this and read all garf stuff (where I got the ratios for just using argonite sand instead of oyster shells)

thanks for the support :confused:

I just experienced with elbow mac. and straws with portland type 1 and I'm having the same problem. I've had great success using the crushed oyster shells and portland type 1 but wanted to try something else. I've let it sit for 3 days and when I removed it it just fell apart in chucks and the rock feels kind of soft. I think I'm going to test this process again with the elbow mac and straws, I know it should work. I'll report back in a few days.
shane
 
suver569

suver569

Member
I'd steer away from the macaroni and straws, or cut way back. That seems to me like it's giving it a weaker base, or something is interferring with the concrete. Possibly some oils or something from the pasta?
Anyways, I used portland type IV, crushed shells, and sand only for a form, not in the actual rock.
 
A

andretti

Guest
Sorry I took so long to answer you but I had to grade a bunch of math tests (just the way I want to spend my weekend)
Sounds to me like you had a batch of bad cement. And two, you want to leave the box open for the concrete to dry. Third, don't use quickcrete. Fourth, try to find some oyster shells, crushed coral something as a base for the cement to grab to. I only use plastic straws to lighten up the rocks and give them texture. Use type II or III portland cement (not quickcrete). Type III is the best and it's usually hard to find. Anyway, for about a 50lb batch, I use 20 cups of cement, 14 cups of oyster shells, and about 7 cups of water. I like a dry mix because I no longer use sand as mold; I just let the batch set up for about 1/2 hour after it's mixed and then shape it to whatever my mood is. :confused:
:mad:
:) If you can't find the oyster shells use the agronite play sand that you have. Mix it up real good so it has the texture of lcottage cheese, let it dry a liitle, then form it on a flat dry surface; I use a 4x8 sheet of plywood. Mine dries in 24 hours then it's off to cure underwater for a month. I mix my stuff using a paint mixer (home depot) $10 and a drill. It's much faster and everything gets mixed up nice & even. Try this recipe and way write back. They also sell oyster shells at nursery stores, livestock feed stores. Maybe go onto the web and see where the nearest place for you is. Good luck. BTW, it took me about 3 or 4 batches before I finally got the ratios correct. Don't give up, just like anything else, it's hard at first but once you get the hang of it, it's easy & rewarding.
 
suver569

suver569

Member
Ok, just thought I'd share some new info (or maybe not new) with everyone.
I made a new piece last night around 5pm, got home, opened it up and it was hard enough to take out of the mold. I pulled it out, and noticed a little to much sand stuck to the surface, and gave it an undesirable look, at least IMO. I like the little bit rougher look of the exposed crushed shells.
I broke out my power washer, and blasted the crap out of all the sand, and wa-laa, sand be gone. It blasted about 90% of the sand off with no problem, and I even could still blast areas that wern't so good looking, into a little bit better shapes. In other words, the surface was still a little manageable with the pressure washer.
When the pics are back working, I'll post em for everyone to see.
 
suver569

suver569

Member
Originally Posted by shiby1510
gee... ur cement dried fast... what kind are u using?
Portland type 4. It's made from orange county in socal. It was pretty much hard as a rock when I pulled it out today. I'll get a UPC on it when I buy another bag.
I basically dont measure anything. I just mix up about 8 cups of concrete, add water slowly until it is just a little bit on the dry side, but still thick and soupy. Then I add probably about 4 times as much oyster shells. I threw in a handful of sand in this batch, which I dont think I'll do again. I dont like the texture, which is why I pressure washed it afterwards, to get some of the sandy texture out, which worked fine.
Anyways, I'll find the bag of the cement I used. It dries super fast. Same goes with the reef plugs I make. They dry in less than 24 hrs.
 
shiby1510

shiby1510

Member
alrighty... thanx... dont think i'll find portland IV tho anywhere around here (east coast).. its hard to find III..
for everyone else that has heard about some of my problems.. i finally found a place that sells crushed oyster shells around me.. :cheer: :jumping: ... it was $13 for a 50# tho :scared:
... o well i still bought it... i also found a place that sells lehigh portland I/II .. i'm thinking this brand is better than quikrete?? anyways its better than the type I i have ... but yah the store was closed once i got there...
I did make a few molds tho... i just made them on plywood and its been about 4 hrs and it already feels mostly dry and hard...
soo maybe i won't need the other cement...
or do u think i should still get rid of the quikrete?
 
A

andretti

Guest
DON"T USE QUICKCRETE!!
When I was at HD last night I read their labels. It's for filling in patches and making repairs, so it is much more flexible than regular concrete. Shiby, I'm SOOOOOOOO happy :jumping: you finally found crushed oyster shells :cheer: $13 is a little pricey, I pay $5.95 for a 50 lb bag, but oh well. Your price per pound will still be way cheaper (I estamate about .24 cents per lb.) than $5 or ??? per lb from the lfs. Keep us posted on your progress... K
 
shiby1510

shiby1510

Member
so r u saying even if it did work with the quikrete... don't use it in my tank?

and in addition lehigh is good right?
 
A

andretti

Guest
Yes, That's what I'm a sayin'. Quickcrete turns brittle and breaks/flakes off after it's been in your tank; even if you've properly cured it. Plus, it has added sand which will produce excess sillicates in your tank and sillicates cause hair algae (and other forms). The stuff isn't horrible...it won't wipe out your tank, it's just not a good suggestion. There are sillicate removers (Seachem makes a great called "seagel") If you've already mixed it well????? :notsure: that's your call, but if it were me, I'd buy a $7 bag of type II or III and go from there. You've already had a few failed attempts and you've put so much research into this as far as asking for :help: So.... do it right and then you can finally be happy :jumping: :cheer: with the fruits of your labor. Good luck and maybe try doing a batch without the molds...just mix it somewhat dry and let it set-up for 45 minutes and then you can mold/shape it to many good shapes. If it does not hold a shape, wait a little longer, it will get there. If water is seeping out of the mix while it's sitting there, it's too wet. I'm not saying it's like playdough (as far as being able to mold it), but IMO this way is much easier. For example, you do not have to pry it out of the mold; you don't have to make the mold; and you don't have to scrub off all the sand :mad: that always sticks to the concrete Good luck.
 
philgmiami

philgmiami

Member
yea can i see some pics please:).. im thinking of making my own rock also :).. dumm ?,what keeps all the material 2gether?.. just portland, oyster shells,tropical play sand and water?,, how many parts per material.. is it1 part portland,, 4-5 parts oyster chells? what part sand and water?
thanks phil
 
philgmiami

philgmiami

Member
can i see pics of your homemade rock?.. sooo you make the shape first with just sand and water, sooo its stuff enough to work with?.. what do you pour on it after?whats the materials? and what are some helpfull hints to do it?,,...thank you
 
shiby1510

shiby1510

Member
yah i made some on plywood and it molded soo much faster... i used quikrete however... i just wanted to see if it would work better with the oyster shells which it did... it is flaking tho cuz of the quikrete i'm sure... so i'll hafta get myself the good stuff... thanks for all the help
:happy:
as for philgmiami... read the other pages of this thread... and it will answer all of your questions... don't be lazy... u gotta read if u wanna be able to do anything right with tanks... there are no shortcuts
 
scarr105

scarr105

Member
Doesn't quikrete make portland cement? I use portland type 1 and it says quikrete on the bag, I think :notsure: .
 
suver569

suver569

Member
Originally Posted by scarr105
Doesn't quikrete make portland cement? I use portland type 1 and it says quikrete on the bag, I think :notsure: .
They do make portland type, but I'd steer away from it if possible. Some people have had success, but I think just one to many unsuccessful attempts have been reported. Plus, it's more expensive...At least in my town.
 
shiby1510

shiby1510

Member
yah i got the quikrete portland I cuz at the time thats all i could find and thats the only portland that H.D carries... atleast around here...
I thought nothing of it at first cuz it said portland and then i start thinking about the name QUIKrete.. which means it already has the sand and such in it which means silicates and all that stuff...
of course the guys on here knew about it already .. so yes i did the same thing and it is no good... it crumbles no matter how u do it and how many times u try... believe me :yes:
 
suver569

suver569

Member
Dang, sorry to hear that. I guess it's pretty much a sure thing to stay away from quickrete then.
On another note, I made a batch last night around 5pm, and pulled them out of there molds today at 10am. That's 18 hours in the mold, and they were fairly hard. Hard enough to hose them off and set them out to fully dry. Will wait till tomorrow to put them in the tank of water though.
 
scarr105

scarr105

Member
my second test with straws and elbow mac was a flop again, I'm going back to crushed oyster shells. My first batch using quikete portland 1 worked wonderful using it along with oyster shells. Just one more week before it's cured, have it soaking in saltwater right now.
 
You must log in or register to reply here.
Top