The Ultimate DIY Rocks!
- Thread starter JohnL
- Start date
mr.wilson
.Registered Member
I like spray foam, but only as a base coat to cover hard edges on overflow boxes and for covering pvc. I find that it sticks well to glass, acrylic and pvc while you are covering it with concrete, then the concrete membrane itself holds it all together and avoids the buoyancy and UV degradation issues.
mr.wilson
.Registered Member
It's a perfect mr. mom job. I was a stay at home dad for a few years there too. I was doing installs at night and on weekends. A home greenhouse is perfect. It's a s much work as you make it. Pay a few kids to help out making rock (until your kids are big enough). Compared to coral farming you lose almost all of the stress, temperature swing issues, start-up costs, and it's much less labour intensive. Sales are simple, and packing is straight forward. You plant your crop and ship it out 3-6 months later.
You're in a good state (geographically) to take on a project like this. Even if you catch a storm, your stock won't suffer. You just need to check the next town for your greenhouse
DeathWish302
Clown Hoarder
Even if they got the mixture right, it isn't easy to foresee and then build what you want the first few times you make rock.
Amen to that!:thumbsup:
I have a rubbermaid tote full of trial-and-error rock. I've made quite alot of 'sump' rock too. I would say if you get the mix, molding process & kuring down before the end of you first bag of OS your doing good. Then again.... maybe I was a slow learner.
Electrobes
Montipora type guy
It's a perfect mr. mom job. I was a stay at home dad for a few years there too. I was doing installs at night and on weekends. A home greenhouse is perfect. It's a s much work as you make it. Pay a few kids to help out making rock (until your kids are big enough). Compared to coral farming you lose almost all of the stress, temperature swing issues, start-up costs, and it's much less labour intensive. Sales are simple, and packing is straight forward. You plant your crop and ship it out 3-6 months later.
You're in a good state (geographically) to take on a project like this. Even if you catch a storm, your stock won't suffer. You just need to check the next town for your greenhouse
And yet another perfect thing going for me.. I live out in the country and we'd be moving into another place even more countrier than that! You've hit all the points square on the nose... all that stress just gone by making rocks, and it's fun too.
My only complaint is that our current water has a pH of 8.3... not sure if a town near here (Most of our moving options) will be any different. Not even remotely slow, it took me about two full batches before I got it right (At least IMO). If your slow then I'm non-moving! :lol:
I'm lovin' the discussions with this thread revived. Thanks J!
Electrobes
Montipora type guy
Yeah I've read this entire thread(s) several times, and many others. What worries me is the possibility of structural integrity being loss when using those methods during the cure (Acid and CO2). I'll always only use tap.. using resins would be costly and a PITA to deal with.
Not sure about water softener though.. it's cheap enough but would it affect rock integrity?
I forgot to ask you mr.wilson (My name is Christian by the way ), do you steam your rocks?
Not sure about water softener though.. it's cheap enough but would it affect rock integrity?
I forgot to ask you mr.wilson (My name is Christian by the way
), do you steam your rocks?
mr.wilson
.Registered Member
Yeah I've read this entire thread(s) several times, and many others. What worries me is the possibility of structural integrity being loss when using those methods during the cure (Acid and CO2). I'll always only use tap.. using resins would be costly and a PITA to deal with.
Not sure about water softener though.. it's cheap enough but would it affect rock integrity?
I forgot to ask you mr.wilson (My name is Christian by the way
Hi Christian, my name is Shawn and I'm a reefaholic. My fathers name is actually Bill Wilson so I could probably start a support group
I guess I missed part of the thread where neutral PH water was discussed as integral to concrete strength. I'm not a concrete expert, but I wasn't aware of that. The biggest concern with structural integrity is using as little water as possible and adding silica fume to guard against sulphate breakdown, common is saltwater (magnesium specifically).
You should use Type HS (high sulphate. Formally called type 50) as it is formulated to protect against sulphate attack for marine use. We have talked about it a few times in this epic thread. http://www.understanding-cement.com/sulfate.html
If you are selling dry rock you may have to stabilize the PH of the rock, but it isn't an issue if you are selling it as cultured live rock. What is the PH of the saltwater if you dry cure your rock for 30 days, without any significant soaking? Some mixes, particularly ones with silica fume don't have significant PH shifts or leaching. They are also stronger, dry quicker, and are more malleable to sculpt.
If I'm making rock by hand I use a polymer modified cement mix so it has a stable PH and cures quicker & stronger. When I use the gunite machine, I use standard portland and aggregates and it too has a stable PH and cures very fast. The gunite machine uses very little water to hydrate the cement so the hydraulic process is much more simple. You can shoot cement onto a ceiling and make stalactites without slumping or the material falling off with it's own weight, it's that dry. They are commonly used for refractory (supporting the ceiling and walls of mines). Steaming isn't necessary with these two methods. If you are producing on a wholesale level, it's may not be worth the effort of steaming.
Electrobes
Montipora type guy
Doh, I remember reading about the discussion of using Type HS as the best choice for it's high sulfate resistance, but must have missed the part about it's lack of large pH shifts or leeching.
My memory sucks (And I am pretty sure you told me this before), but when you say polymer modified cement, do you mean something like the Xyphex products?
I use white Portland as my cement mix and my pH readings after steaming (About 8 hours total, with a long ramp-up time to 145F and then ramped-down time), plus a couple days of cooling, is about 11. It usually takes me about 4-6 weeks to get the pH down to 9 when water curing at 130F temperature (To help leech the pH out). As you can guess, a lot of this came from IR's methods.
This may be a stupid question but do they make white Type HS cement mix and where do you find it? I called my local Cemex distributor and they said no one local carries it (Including them), if I wanted it I would have to order like 4 pallets of it.
My memory sucks (And I am pretty sure you told me this before), but when you say polymer modified cement, do you mean something like the Xyphex products?
I use white Portland as my cement mix and my pH readings after steaming (About 8 hours total, with a long ramp-up time to 145F and then ramped-down time), plus a couple days of cooling, is about 11. It usually takes me about 4-6 weeks to get the pH down to 9 when water curing at 130F temperature (To help leech the pH out). As you can guess, a lot of this came from IR's methods.
This may be a stupid question but do they make white Type HS cement mix and where do you find it? I called my local Cemex distributor and they said no one local carries it (Including them), if I wanted it I would have to order like 4 pallets of it.
Electrobes
Montipora type guy
I forgot to also mention and ask one other thing...
I am only making dry rock to sell. I doubt I'll get into live rock making, base rocks is it for me... my only other possible expansion would be doing custom pieces like rock walls or more sculpted rock formations.
I think I understand you last post about the reason you don't steam the rocks: The 30 days of curing using your concrete mix results in already low pH, drastically cutting kuring times? I take it steaming only helps with strength?
I am only making dry rock to sell. I doubt I'll get into live rock making, base rocks is it for me... my only other possible expansion would be doing custom pieces like rock walls or more sculpted rock formations.
I think I understand you last post about the reason you don't steam the rocks: The 30 days of curing using your concrete mix results in already low pH, drastically cutting kuring times? I take it steaming only helps with strength?
DeathWish302
Clown Hoarder
Interesting article Mr. Wilson! The question I have is what is the expected life of rock w/o silica fume? I have some that is about 3 years old and it doesn't seem to be decaying at least on the surface? I know sidewalks at work have this sulphate attack occurring, as the top surface is very scarred. That sidewalk is 34 years old though, so if my rock w/o silica fume lasts that long I would be happy. Where are you finding silica fume? I'm guessing this isn't something the big chain home improvement stores stock???
Also you say you use a polymer-modified cement mix. Is this similar to the polymer-modified grout mix from the Lowe's/HD? I have seen the white non-sanded polymer-modified grout mix, but the idea of 'polymer' and not knowing what it contained has scared me away form trying it.
I love this thread and the various avenues it has covered in the past months. It seems you learn a new material, tip or trick & production method every page.
I vote TOTM....
Also you say you use a polymer-modified cement mix. Is this similar to the polymer-modified grout mix from the Lowe's/HD? I have seen the white non-sanded polymer-modified grout mix, but the idea of 'polymer' and not knowing what it contained has scared me away form trying it.
I love this thread and the various avenues it has covered in the past months. It seems you learn a new material, tip or trick & production method every page.
I vote TOTM....
mr.wilson
.Registered Member
Doh, I remember reading about the discussion of using Type HS as the best choice for it's high sulfate resistance, but must have missed the part about it's lack of large pH shifts or leeching.
My memory sucks (And I am pretty sure you told me this before), but when you say polymer modified cement, do you mean something like the Xyphex products?
I use white Portland as my cement mix and my pH readings after steaming (About 8 hours total, with a long ramp-up time to 145F and then ramped-down time), plus a couple days of cooling, is about 11. It usually takes me about 4-6 weeks to get the pH down to 9 when water curing at 130F temperature (To help leech the pH out). As you can guess, a lot of this came from IR's methods.
This may be a stupid question but do they make white Type HS cement mix and where do you find it? I called my local Cemex distributor and they said no one local carries it (Including them), if I wanted it I would have to order like 4 pallets of it.
All of my local big box stores carry white portland. You might have to look in the flooring section. It usually costs a little more. I use some white for a change of pace, but I prefer grey. I find white needs some pigment to give it some depth. You can use water-based acrylics, watered down. Just sponge it on or spray it on with a plant sprayer. Believe it or not, the water-based exterior paint stays on as good or better than epoxy. Some people use oak leaves and other natural elements. I find cement tinting chemicals to be too hard to use unless you are tinting the whole rock one colour. You have to mix the colours to come up with realistic ones, because they come in red, yellow, and grey and black. I think it was my mix, but the white portland tended to crack more.
The Zypex products are great, but they are for waterproofing through crystallization. They would deter any biological activity within the rock. I use that stuff on the external structure of cement tanks and pools. The polymer modified cements I was speaking of are ones like Quickwall or Hydraulic Water Stop by Quickrete. Don't let the name fool you, water penetrates through the cement. It has a tighter pore matrix so there is more surface area, less void space. If you use calcium hydroxide, silica fume, and fiberglass fibers in your mix, you get quicker setting which gives you a more stable PH.
I can only hold so much information in my brain as well, then I have to remember where I put it. What was the point of steaming again? I noticed in a search that it is used to harden/strengthen cement castings so they can be taken out of the molds quicker. It speeds the hydraulic process for initial strength, so it would trim off the first two weeks of dry curing perhaps. I remember Co2 was another factor that sped up the process. From my standpoint, time is on your side, and waiting while some rocks sit on a skid for 30 days uses less resources than steaming. Dry curing will allow the rock to hydraulically cure allowing calcium to stabilize and Ph to be buffered less. Throwing the rocks in water before full dry curing will compromise strength and cause more calcium to leach from the rock, thus raising PH.
Soaking cement in soft RO/DI water is the equivalent of soaking it in acid. It dissolves the calcium carbonate in the MMR and acts like a calcium reactor. This is why you get a PH reading of 11. Soaking it in hot water will further this buffering reaction.
If I read your method correctly, you are not dry curing the rock for 28 days? Try making a rock with your usual recipe, let it dry in a cool place out of the sun for 28 days, then soak it for one day in tap water, then drop it into a bucket of saltwater for a couple of days. I would like to know what PH value you get. I will make some rocks and test them for PH shifts as well. We'll meet back here in a month
Electrobes
Montipora type guy
Ah sorry, white portland I actually get from my local Cemex currently (It's what I use), I meant type HS cement. I just now got back from Lowes and they will call me back as they think they found a supplier who will ship 3 bags. I had to explain to them what HS was.. talk about fun. Hopefully it works out as I'd really like to give it a try.
I dunno what it is, but I just can't bring myself to color the cement. Since I just sell base rock, white portland works great for me. You're right about the rock looking like it has no depth, but screw around with photo editing to make the shadows show true and people realize what's actually there.
That's right, I think I remember you telling me that, ug I must be getting old in my young age.
Would you recommend adding silica fume, calcium hydroxide, and/or fiberglass fibers in a mix with the white portland cement?Steaming basically takes what dry curing does (Hot, humid environment), but does so faster. The idea is that after the mix, you let it sit long enough to hardened and remove from the mold (I just leave it overnight). You then steam it for about 5-12 hours.. depending on who you ask. You go no higher than 150F, because it supposedly makes the crystals in the cement grow like crazy causing micro-cracks. After the steam process, you let it cool down for a couple days.. and voila, you supposedly have rock that is the same as rock that cured for 28 days.
I didn't know that about RO/DI water doing that, thankfully I only use tap.. my poor RO/DI unit would just collapse. You don't even want to know how fast my DI resin gets exhausted because of the water here... it's crazy. The soaking it in hot water was also suggested by IR, which is why I did that. She used the sugar cube in hot tea example.. which made sense (It dissolves out faster than in cold tea). I never saw it like that.. I take it I should keep the water at room temperature? That would definitely cut the electricity bill via shortening the time my titanium heaters come on, so you know I love this idea!
If I read your method correctly, you are not dry curing the rock for 28 days? Try making a rock with your usual recipe, let it dry in a cool place out of the sun for 28 days, then soak it for one day in tap water, then drop it into a bucket of saltwater for a couple of days. I would like to know what PH value you get. I will make some rocks and test them for PH shifts as well. We'll meet back here in a month
Yeah you have it right.. I make the mix, let it harden overnight. I then steam them for about 8 hours (Long ramp up and down times with 140F being max temp) then I let them cool down for a couple days, to which I later water cure them in 130F water till the pH drops to 9 (Usually takes about 6 weeks).
So you suggest that instead of the 28 days of curing in a hot humid environment, I should try 28 days in a coolish environment without misting? When I soak it underwater for a day.. should I keep the temp at room temp (About 70F)?
I am definitely happy to try any experiment.. always fun to learn new things!
mr.wilson
.Registered Member
Doh, I remember reading about the discussion of using Type HS as the best choice for it's high sulfate resistance, but must have missed the part about it's lack of large pH shifts or leeching.
My memory sucks (And I am pretty sure you told me this before), but when you say polymer modified cement, do you mean something like the Xyphex products?
I use white Portland as my cement mix and my pH readings after steaming (About 8 hours total, with a long ramp-up time to 145F and then ramped-down time), plus a couple days of cooling, is about 11. It usually takes me about 4-6 weeks to get the pH down to 9 when water curing at 130F temperature (To help leech the pH out). As you can guess, a lot of this came from IR's methods.
This may be a stupid question but do they make white Type HS cement mix and where do you find it? I called my local Cemex distributor and they said no one local carries it (Including them), if I wanted it I would have to order like 4 pallets of it.
Sorry, my original answer to your stupid question was equally as stupid. I missed the HS in your white portlan cement question (edited). No, I doubt you will find it readily. I find white needs some pigment to give it some depth. You can use water-based acrylics, watered down. Just sponge it on or spray it on with a plant sprayer. Believe it or not, the water-based exterior paint stays on as good or better than epoxy. Some people use oak leaves and other natural elements. I find cement tinting chemicals to be too hard to use unless you are tinting the whole rock one colour. You have to mix the colours to come up with realistic ones, because they come in red, yellow, and grey and black. I think it was my mix, but the white portland tended to crack more.
The Zypex products are great, but they are for waterproofing through crystallization. They would deter any biological activity within the rock. I use that stuff on the external structure of cement tanks and pools. The polymer modified cements I was speaking of are ones like Quickwall or Hydraulic Water Stop by Quickrete. Don't let the name fool you, water penetrates through the cement. It has a tighter pore matrix so there is more surface area, less void space. If you use calcium hydroxide, silica fume, and fiberglass fibers in your mix, you get quicker setting which gives you a more stable PH.
I can only hold so much information in my brain as well, then I have to remember where I put it. What was the point of steaming again? I noticed in a search that it is used to harden/strengthen cement castings so they can be taken out of the molds quicker. It speeds the hydraulic process for initial strength, so it would trim off the first two weeks of dry curing perhaps. I remember Co2 was another factor that sped up the process. From my standpoint, time is on your side, and waiting while some rocks sit on a skid for 30 days uses less resources than steaming. Dry curing will allow the rock to hydraulically cure allowing calcium to stabilize and Ph to be buffered less. Throwing the rocks in water before full dry curing will compromise strength and cause more calcium to leach from the rock, thus raising PH.
Soaking cement in soft RO/DI water is the equivalent of soaking it in acid. It dissolves the calcium carbonate in the MMR and acts like a calcium reactor. This is why you get a PH reading of 11. Soaking it in hot water will further this buffering reaction.
If I read your method correctly, you are not dry curing the rock for 28 days? Try making a rock with your usual recipe, let it dry in a cool place out of the sun for 28 days, then soak it for one day in tap water, then drop it into a bucket of saltwater for a couple of days. I would like to know what PH value you get. I will make some rocks and test them for PH shifts as well. We'll meet back here in a month
mr.wilson
.Registered Member
Yeah, I caught that one and somehow double posted when I tried to edit it.
Yes, painting can make it look gaudy. I always think about the base rock Caribbsea used to sell with that awful purple and blue Ice cream swirl epoxy splashed on it. It was supposed to look like coraline, but it ended up looking like the rock should be mounted on a sugar cone.
Calcium hydroxide based fast setting agents are available at your local store, but you can play around with hydrated lime mixtures or look up recipes. I'm not holding back any secrets, I haven't ever used the stuff, but I'm sure it's in the premixes I use. The fiberglass mesh is for strength and holding shapes, but I find it cuts back on the amount of water needed so it will stabilize PH in that respect. Silica fume is a must. Once again, I've been buying premixes or ordering custom mixes. I'll look up the recipe I was given by a concrete engineer. It's what I give the concrete supplier when I order custom mixes.
I remember that to be the plan, but it looks like yours is still coming out at a Ph 11 if I read your post right. I agree with the chemistry of it, but if you have some space to store it, a 28 day wait seems a lot more like my style http://www.reefcentral.com/forums/images/smilies/read.gif
I didn't know that about RO/DI water doing that, thankfully I only use tap.. my poor RO/DI unit would just collapse. You don't even want to know how fast my DI resin gets exhausted because of the water here... it's crazy. The soaking it in hot water was also suggested by IR, which is why I did that. She used the sugar cube in hot tea example.. which made sense (It dissolves out faster than in cold tea). I never saw it like that.. I take it I should keep the water at room temperature? That would definitely cut the electricity bill via shortening the time my titanium heaters come on, so you know I love this idea!
I can't say if IR's methods are right or wrong, I can only say how I see the process. Yes you can dissolve a sugar cube in hot water and acid conditions quicker, but in our case we have a 12' stalk of sugar cane and we want to keep it in our tank. The slow release of sugar, or calcium in our case is the same process we strive for with natural live rock. The reason why cement based rock works so well for us is its chemical similarities to natural calcareous rock. Our goal is to complete the hydraulic process, not to dissolve the rock or the calcium within it.
I test the water when I use cement based rock, and so far it has never gone north of 9. Bare in mind these are new systems with no livestock. After a few weeks of biological activity the PH comes down to 8.4. I have no experience with standard portland mix rock, so I don't want to come across as someone who is telling you any one method is wrong or unnecessary. I'm looking forward to getting to the bottom of the PH question.
So you suggest that instead of the 28 days of curing in a hot humid environment, I should try 28 days in a coolish environment without misting? When I soak it underwater for a day.. should I keep the temp at room temp (About 70F)?
I am definitely happy to try any experiment.. always fun to learn new things!
The proof is in the results you get. We will see. The only strength issues I foresee with our application is sulphate attack. This is an issue of cement additives, and not curing practices. Are you using salt in your recipe? This will effect a number of chemical reactions, so that's a whole other issue.
Electrobes
Montipora type guy
:lol:
Thanks I appreciate that, I'll definitely tinker with variations of recipes and report what I find.
I think you're right. The chemistry is fine for the growth of the crystals, but the problem is the pH leeching, which steaming does not help.
Yeah you're absolutely right. All these idea's were experimental. In a sense I could make it work, which I have, but it is not close to efficient. I could make my life a whole lot easier just going with the 28 day cure, and suffer far less problems when dealing with pH leeching.
Yeah that makes sense, and those are definitely great results.. far better than my own. I have a feeling when I duplicate what you do in the experiments I'll get the same results with far less use of resources than with my current method.
Looking at our discussion and your current results, I believe you're right about the only issue being left is sulphate attack. If I get lucky and am able to get a couple bags of Type HS cement, I'll make a batch via your method and also report those findings as well.
Electrobes
Montipora type guy
Ack, messed up, ignore this post
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