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Hypertufa Mix Not Setting.

10 years ago

I have been making these troughs for 3 years now and for some reason the last 3 batches I have made did not set. I have two test batches right now that I did changing the formula by adding more portland cement (I doubled it). And another batch where I added sand to the mix. It has been 48 hours and I can't take them out of the molds. So it is not looking good. Every other batch I did in the past set just fine within 24 hours I could remove and rough up with a wire brush and then let cure for a minimum of 3 weeks. So what am I doing wrong?

Comments (21)

  • 10 years ago
    last modified: 10 years ago

    Why did you change your recipe if it was working for you? What recipe are you using? Just saying you doubled the Portland doesn't tell us what else you put in the recipe. Portland cement can go bad, how old is yours? You say it's been 48 hrs. and you can't take them out of the molds......do you mean they are still wet or they are stuck in the mold? Give as much information (recipe, do you mix dry ingredients before adding water, what mold release, what kind of molds) as you can so we can help.

  • PRO
    10 years ago

    Hi Bille_ann,

    My portland cement is less than 3 weeks old, same with the per-lite, the peat moss is older, not sure.

    I changed the recipe because I made three batches that did not set. I have made 2 more batches using two different recipes and they did not set either. I have always mixed till sqeeze a ball and get a drop of water. So I did some research and it said that maybe the peat moss is too dry, so I added more water. Still crumbles.

    They are not stuck in molds, they never set, I have waited 3 weeks for one batch and it never hardened. If you remove from mold it just crumbles. For three years I have removed from molds the next day and then use wire brush to shape and then cure for a minimum of 3 weeks. All were great!

    The original recipe I have used for three years with no problems what so ever till recently is:

    2 gallons peat moss, 2 gallons perlite, 1 1/3 gallon portland cement, 1 cup fibers

    Recipe#2

    3 parts portland cement, 4 parts peat moss, 5 parts perlite, fibers

    Recipe#3

    1 part portland cement, 1 part sand, 1 part peat moss, 1 part perlite, fibers

    None of these recipes has set. All have crumbled.

    As I said, I have had no issues at all from my very first batch three years ago and I make multiple batches a year. I have probably made all total 20 plus batches, but this summer they just quit setting. I usually make a very large batch, so I even reduced to a very small batch to see if that would help (plus I am wasting lots of product!), but that didn't help either.

    If you have a recipe I will try that one. I am desperate.

    Thank you

    Donna

  • 10 years ago

    Your recipes look fine and should be setting up. This will sound dumb but check the bag of Portland cement and make sure it is Portland cement and not another product, like mortar mix or stucco or sand/topping mix. If someone picked it up for you maybe they bought the wrong product or were told where the product was bought that "this" product will work for/in place of Portland cement. The Peat moss being too dry is not a really factor. Every time you make a hypertufa mix you are using different amounts of water due to humidity and what ingredients are used. You don't need fibers. Unless you are making ultra thin pieces you are just wasting money. Builders sand will add strength to you pieces.

    I use different recipes for different looks. If it's going to be rustic I use a recipe with chunky pieces of peat moss. If it's modern use white Portland Cement/white sand/perlite/vermiculite. If you are carving use a recipe with sifted peat moss.

  • PRO
    10 years ago

    Definitely Portland Cement. Builders sand is what I used on that recipe and it completely fell apart. It's dust now.
    I just don't know what to do. I have a festival in October and it looks like I won't have but 3 planters that I made last spring. The rest have just fallen apart. Below is one of my troughs. I have had this one for two years and it looks even better now. I like them more the older they get.


  • 10 years ago

    Try 1 part portland cement, one part perlite, and go out an buy a new bag of cheap potting soil and use 1 part potting soil (which is mainly peat).

    I have seen posts where people have had problems with peat that is too dry. That may be a small part of your problem. It seems that you are mixing a large batch, 2 gallons , are you using all the mix to make one pot? Or are you making muliple pots? Try to Mix enough for one smaller container at a time. Mix well all ingiendents dry. - like you mixing a cake, then slowy add water and mix well. When you think you mixed it enough, mix it 5 more minutes.

    I have always used potting soil (instead of peat moss) and I store it in sealed containers between batches ( so it does not dry out) . I teach hypertufa classes at a gareden center and they provide potting soil for the class. It has always been damp and I have never had a problem. It is important to keep the portland cement in sealed containers also and I never buy broken bags that are sittng around in store. Finally I will assume that the outside temps are above 50 f. which is important for the cement to proberly cure.

    I rarely use sand. And agree with Billie, no fibers unless you are making huge pots. I ocassionally use vermiculite, but if I do, I will use a little less perlite.

    From looking at yours pots, I beleive you have too much agrigate ( peat, sand, perlite, vermiculite) mixed with your portland, and possibly your peat may be too dry, and when you mix the dry peat may not mix well with all the other ingiendients.

    If nothing else has worked - why not buy some potting soil and mix a different ratio, and also make a smaller batch.

    Mike

  • 10 years ago

    the same thing happened to me earlier this year. The culprit was the peat moss; it was so dry that it sucked all the moisture away from the Portland so it could not set properly. At first I thought the Portland was too old, so I made something with just sand and Portland and that came out just fine. Use more water or dampen the peat moss some before mixing; you could also make up your batch, let it sit for 10-15 minutes and will probably notice how dry it is; add more water.

    It is very frustrating to make troughs and then not have them strong enough to get out of the molds. I had about $400 worth do that to me last spring! Ouch!!!

    My old standard formula is: 1 part Portland to 1.5 parts sifted peat moss; 1.5 parts perlite and a handful of reinforcing fibers. Always works for me.

  • 10 years ago

    Been wanting to get started with hypertufa and had a question. If so many people are having problems with peat moss being too dry, would it be effective to soak the peat moss before and then add less water while mixing? Or would that mess up the ingredient balance?

  • 10 years ago

    the ingredients need to be thoroughly mixed while dry so that the Portland can cover all of the particles of the peat moss and the perlite (or whatever else you toss in there) as it is the Portland that holds it all together. If the peat moss is soaked, this can't be accomplished. That is not to say that the peat moss needs to be powder dry, but soaking would make it too wet.

  • PRO
    10 years ago

    What club53 says is right. I have always mixed dry ingredients thoroughly before adding any water. I watched many youtube videos and read many blogs before I ever made my first trough. It is helpful and you can see all of the details that are skipped in just a written formula. From my very first batch I have had no problem in three years. I think what billie_ann says about the peat moss makes sense. So I am not sure that is the issue. But I am tenacious so I will figure it out. Thank you all for the comments and tips.

  • 10 years ago

    Good to know, that's why I asked before trying. I've been reading and watching everything I can. I think I will start small to work out any problems if they do arise, then scale up from there.

  • 10 years ago

    I'm having the same problem - using the same recipe (3/3/2 peat moss/perlite/cement), same procedure as has set up in the past in 24-48 hrs and now not getting hard after a week or longer. I've tried multiple bags of portland cement, and even got a bag of "topping mix" (sand and portland cement) that someone suggested to use in a "beginner's mix" - and that is the worst of all. I'm wondering if the water could be the problem? We have well water (untreated) that has a fair amount of calcium and iron in it...??? Does anyone konw about possible water issues?

  • 10 years ago

    Just trying to help so just read then take a look at your process.

    I used well water (heavy iron content-untreated and treated) for many years before we got municipal water and had no problems. You said they were setting up before this, were you using the same well water? Anyone in your area use well water to make a batch of concrete for fence posts, concrete pads or any other cement project? Are their projects setting up?

    Once again I'd like to say that I've had no issue with peat moss that is too dry. I use bales of peat moss that has sat over winter in my shed or bake in the shed during the summer. For certain hypertufa mixes I sift the peat moss to get a very fine mix, can't get any drier than super fine particles of peat moss. Don't they use peat moss in very dry climates? Don't think I've seen any posts from Arizona members that their peat moss is too dry. BUT maybe they dampen their peat moss and think it's done all over the U.S. the same way. If you do a search on this forum regarding mixes not setting up ( at least before the latest group of posts) it's due to incorrect ingredients or not mixing correctly/completely. If your mix was setting up before this then there has to be something different in the ingredients or mixing process. Sometimes we don't even realize what we're doing is different. There was a poster, a long time ago, that was using sand that a neighbor gave them. It was sand that was used on icy roads and was full of salt and some other chemical. When they posted, they kept saying the ingredients were Portland cement, sand and peat moss.

    Bags of Portland cement have a shelf life, shouldn't be allowed to freeze or stored over 100 degrees Fahrenheit, according to the manufacturer I use. Never store Portland cement on a concrete floor. It will absorb moisture from the floor. If there are small soft lumps, easily broken up, in the bag you can use it but if there are small hard lumps, not easily broken, and the rest is soft you shouldn't use it.

    I hope that those of you that are having a problem can figure out the cause and come back and post your solution for others to learn. This is really a fun hobby but not if you are having failures.

  • 10 years ago

    Hi:

    It's the dry ingredients sucking up too much of the moisture from the concrete and preventing the concrete crystals from "grabbing" the dry ingredients. It happened to me twice this year -- the first time in 12 years of making troughs. Add more water; let your mixture set for about 15 minutes and you will probably find that it is too dry; so add more water and there you go.

    At first I too thought it was expired Portland. It was not enough water.


  • 10 years ago

    club53, Are you using concrete?

  • 10 years ago

    Type Ii Portland

  • 10 years ago

    Your post above says "concrete" so I assumed you were using concrete. What is type li Portland? I've never seen that designation just the 5 types I to V

  • 10 years ago

    It is just Quikcrete Portland cement. Sometimes I forget cement and concrete aren't the same thing lol

  • 10 years ago

    I don't mean to be picky but this is why newbies get confused. This forum went through this before when people didn't use the correct terminology. Yay, yay, sounds picky but newbies go looking for these ingredients. There have been a few times when someone was trying to use concrete mix for Portland cement because they saw it here. The product you need is Portland cement type I or type I/II not type Ii.

  • 10 years ago

    mea cupla

  • 10 years ago

    I'm only four months late with this, but for future problems....

    When you hit this kind of problem, STOP with the hypertufa, and find out if it's the cement or one of the other ingredients.

    First - are there any chunks in the bag of Portland cement? If there are, it's too old. Picking out the chunks and trying to use the fine stuff won't help -- dump it. It's been exposed to moisture in the air and has cured, even as powder. There's absolutely nothing you can do.

    Second - find some small throwaway containers like plastic cups to do some testing with just cement and sand and two kinds of water, a bottle of distilled water, and your tap water. Mix 1 part cement (a part being something like a quarter or half a cup) with 2 parts sand, and put it in one of your disposible 'molds'. Right afterward, wash out the mixing bowl and do the exact same thing, but use your tap water. Give them a day or three and see what happens. Make sure to mark them as to which kind of water you used.

    If one of them hardened and the other didn't, it's the water.

    If neither of them hardened, it's the cement. When YOU bought it has nothing to do with it-- how long it was sitting at the store is probably the reason. Always use a source with high turnover.

    If both hardened, it's time to start adding the other stuff: the perlite & peat moss, but one at a time. Next, try cement + sand + perlite + water. What happens? If it hardens, mix cement + sand + peat moss + water (leave out the perlite).

    My guess is that it's either bad cement or contaminated/treated peat moss.

    User thanked sixtoomanycats84
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