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demaris_gw

Newbie fails again

21 years ago

Well, I got some Portland cement, made a mix of 1 Portland, 1-1/2 peat, 1-1/2 perlite. After 36 hours, just as crumbly as my first bad try with sand mix.

I am convinced it is the peat, based on my experiment with just the sand mix and peat, sand mix and perlite, sand mix alone. The peat mix didn't harden.

So why did I try using this darn peat again? DUH!

Does anybody have any knowledge of the chemistry of peat that might cause this? It is very old peat, very dry, but isn't peat peat?

Guess I'll get some vermiculite....

Comments (8)

  • 21 years ago

    Demaris,
    This has likely been said before, for that I apologize;
    After you have made sure that your dry ingredients are thoroughly mixed, add a little of the liquid and mix again, adding more liquid as needed. Because your peat is very dry you may need to walk away from your mix for say uhmmm 5-10 minutes, mix it up again and add more liquid. Then let it slake again (the gel process is starting in slaking) mix it up again and begin your project. Sounds like your things dried too quickly so once done cover with plastic and allow for your self to come back in about an hour to see the progress. Add a little water with a spray bottle and cover with plastic. After the initial set of 6-12 hours you should still continue to mixt the project or as others do consider more than just misting by using either a dampened cloth or submerging in water, (only after the initial set though).
    The mix that you refer to cement peat and perlite has little in the way for the cement to bond to, except the perlite. Cement is a dry glue and adding even a small amount of sand to the mix may help distribute the cement better.
    Don't give up, You are learning so much. Consider this part of delayed success.
    Dena

  • 21 years ago

    Maybe you aught to get a fresh bag of peat. Maybe there is something in your peat that is retarding the setup of your portland, like some form of carbohydrate. I used just a little cocoa hull mulch in a batch a month ago, and it took 3 weeks for it to even get hard enough for me to pick up. It sure smelled good though. I would recommend that you use sand in your mix. It gives the portland crystals something to hold onto when they form.

    Jo

  • 21 years ago

    I was very careful to follow the instructions about waiting and adding more water. I used the first recipe in the first FAQ on this forum, which was submitted by "several members" so I figured it would work. Maybe I am just not being patient enough. I will continue to mist and cover and see what happens. BUT - I WILL get rid of that peat. In any case, I have a major grudge against it :-)

    Does hypertufa get warm when it cures, like concrete? I have never felt even one degree of warmth in my things.

    I am not giving up! Next try - add sand, use some vermiculite or NEW peat. Yes, I am learning, and I can live with that. But the concrete leaves were so DARN easy compared to this....

  • 21 years ago

    Hi Demaris
    There are some peat moss that are 'very' acidic.
    You might have one of those.
    I think you should try a different peat moss.

  • 21 years ago

    Due to peat's GREAT ability to shed water, I am going to pour very hot water over my peat for my next project, then let it sit overnight.

    When I'm ready to begin, I'm going to grab handfuls of wet peat and squeeze out as much water as I can, THEN mix with the perlite, THEN with the cement, THEN add water. I won't be measuring the water, just adding it gradually; I know the moisture still in the peat will change water requirements.

    Also, is your peat treated in any way, like added fertilizer or anything? Chemical fertilizers can really affect the mix, which is why potting soil isn't used unless you KNOW it doesn't contain fertilizers (most do).

    Good luck on your next batch!

    Sue

  • 21 years ago

    "Due to peat's GREAT ability to shed water, I am going to pour very hot water over my peat for my next project, then let it sit overnight.
    When I'm ready to begin, I'm going to grab handfuls of wet peat and squeeze out as much water as I can, THEN mix with the perlite, THEN with the cement, THEN add water."

    What have you been doing up to now?
    Were your previous methods failing?
    Just curious.

    I use bone dry peat, mix, apply immediately then mist and cover. No slaking here...unless I add lime:)

  • 21 years ago

    Sue, I didn't know about fertilizers affecting the cure. That is very interesting. I use the perlite with miracle grow in it and luckily have no problems.
    I like using wet peatmoss. It sits outside in the rain and so I have no choice, but I found I like using it wet. Cuts down on the dust alot.
    Tufa isn't "rocket science", but sometimes I feel it can come close!

    Jo

  • 21 years ago

    Hi I always mix mine in a wheelbarrow,Put the peat moss in and then water and get good and wet. now put in perlite or vermiculite and mix it and then your portland cement last mix it up real good. I also use fibers in the mix. I use equal parts of peat,perlite and cement. i have just started making pots and lanterns this past month,having real good luck so far.

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