You should be able to make tufa in your cellar no problem -- don't know what you situation is, just be careful of the dust -- if your furnace is down there, you don't want it pulling in all that fine cement dust and/or circulating it through your house. I cure tufa in my cellar where it's around 68 all winter, wrapped in plastic or stored in plastic containers (whatever your preference), just keep in the moisture. It's necessary to keep tufa (concrete) moist so that it will cure correctly.

Hi Luvherbz, I have the same situation here. I'm setting up shop in my cellar too. The problems I've tried to address so far are dust & keeping the pieces warm and damp enough to cure. My basement generally stays 50-60 degrees (10-15C) during the winter. I worry about the lower temps causing the curing to be too slow or not at all. Since my work tends to be small, I've set up some plastic shelves wrapped in plastic to make a place to be able to keep the humidity and temps up for good curing.

To minimize the dust from mixing etc.,I have a variety of buckets and containers with tight fitting lids to be able to shake my dry mix together and then let sit covered 10 minutes to let the dust settle and then mix in the water or whatever.

So the things that applied outdoors have to apply indoors too. That is, enough warmth and keeping the pieces hydrated well enough during the initial setting up.

I've also tried to make my work area as self contained as possible to keep the dust from being sucked through the furnace and consequently the whole house. Good luck.

Hi Rock
A small broken chest freezer with a small lightbulb hanging in it will keep your tufa and concrete moist and toasty for curing.
Makes a great work table as well.
They are also free from repair places or your local recycler. At least here in BC they are.

I'm not all that quick, it just occured to me a fridge would work really well.
Fill the vegi crisper with water and the shelves would be great curing tufa. a few srips of old bed sheets hanging in the water and drapped over the tufa would keep it wet or you could just mist the whole shootin' match.
If you disconnected the light shutoff when the door closes that bulb would warm it up.

Be safe!
Mask up indoors at all times and remember that the dust from your work will linger in the air well after you're done pouring or finishing.Would HIGHLY recommend an air cleaner(portable ones are on the market from Shop-Vac or Lee Valley)And change the filters regularly.Am I overcautious?Nope,I want to live long enough to annoy my children.Others in this forum may not be as worried as I,but a couple of years ago,there were a few tales here that pushed me to be careful with the dust.
Cheers from here

There are also high quality furnace filters that will remove the dust and in some cases odor to keep it out of your home.
They are costly but some are designed to be cleaned and used for years.
A good investment if you plan on making mud in the basement all winter.

Here's my routine - sand and peat moss already mixed in big Rubbermaid tub on outside deck. Ditto cement. Put on warm outerwear, put mix and cement in plastic dishpan (even outside use mask) wearing heavy duty rubber type gloves mix and mix using hands to pulverize ingredients together. add water until moist then bring into my warm kitchen and proceed with project(mask off) put projects in plastic bags from Fred Meyer grocery store. Wait 24 hrs and unmold - put back in plastic bags and set around the utility room ( never below 55 degrees and in the daytime at least 65) If you are hampered by space or complaining spouses (I'm so lucky) put under the bed or in some closet only you use. After a week or so I keep looking because I'm impatient but unless it's beginning to look a little lighter in color I wait an hour or so and check again. When I have intuited it's time to remove from plastic, probably not less than a week)I leave it out in the room temp (I run warm so it's usually about 68 degrees in the house. It sits until the lightest color I usually see and then I seal it with a 100% silicone sealent Result: lots of planting containers that are non-toxic and never have fallen apart. KISS you guys :)

Error! Sealed with 100% ACRYLIC not silicone

Thanx to everyone.....you've given me much to consider, primarily regarding the furnace and dust particles... looks like I will be waiting until next spring to continue with my small works of tufa.....I appreciate your cautions to always be safe.....which I intend to do....

The instructions I have for tufa include that once unmolded after 24 hours...what I've done is water down the piece for approximately 10 days.... I don't see here where others do the same.....

Luvherbz

Upon reading about furnace filters(we don't have a furnace,,thankfully!)I would caution you that the filter,if its a reusable one,be checked and cleaned weekly.Otherwise,a dirty filter makes the furnace work harder than it has to.
Don't let a little cold weather bother you-If you have a basement,go for it!Be safe,have fun,become addicted!!!
Cheers from here

More about that dust indoors:

Rick is right -- that dust -- it's bad stuff (says so right on the bag -- carcinogenic is the word they use!!). Mixing dry ingredients outside is a good idea. Also, when you unmold your project and scrape the surface to texture, that creates lots of dust too. Wear your mask indoors, and, again, that dust should not be allowed to get into your furnace and circulate throughout your house. One thing that helps is to rest a small exhaust fan (cheap) on the ledge inside a a cellar window and hang plastic sheets (also cheap) from the rafters to make a little ventilated room (my cellar is not finished) sort of like they do in auto body shops. That way, a good portion of the dust gets sucked outside and cuts down on the cleanup, etc.

You can work inside, just think ahead and you'll be fine. It's a good way to while away the long winter evenings, and get some exercise so you don't have to turn up the heat and use that expensive heating oil :).

Hi Luvherbz
The reason you don'[t see many of us keeping projects damp for ten days is we're too impatient.:)
I started curing for about ten days, but now I cure for 4-7 days to get the stuff out of the way.
You are doing the right thing. Your concrete and Tufa will be stronger for it.

Have a question: Am I living in the dark ages or something? I was originally taught and continue to read that that to get a good cure on concrete it needs 28 days to do its thing, and that rushing the cure makes the pieces weaker. Do the 7 and 10 day "cures", etc. really make a product that is weaker?

What do you think?

Have a question: Am I living in the dark ages or something? I was originally taught and continue to read that that to get a good cure on concrete it needs 28 days to do its thing, and that rushing the cure makes the pieces weaker. Do the 7 and 10 day "cures", etc. really make a product that is weaker?

What do you think?

Hi Club
Curing is a funny thing. Most curing takes place the first week and continues for another 3 weeks.
But the benefit after the first week seems minimal.
So I aim for a seven day cure although I may remove the item from it's water or steam bath earlier then mist it for a few days.

As,I believe,Tango said,the great projects of the Roman Empire are STILL curing.Of course,at a much slower rate.
To speed up a cure,use less water,and use an admix.Or,go all the way and do 100% admix.
At the Seattle Gift Show earlier this year,a wholesaler of hypertufa products just laughed about any careful curing beyond a couple of days.So,take your pick.Who's right?who knows?
Cheers from here.

Thanks for the views. The Hoover Dam is still curing too --the concrete on the inside (they say anyhow) is allegedly still wet. My troughs, etc. being just a tad less ambitious, will, according to everybody's best guesstimates, cure sometime between 7 and 28 days. So, being lazy, after the initial set and texturing, they'll just get wrapped up, sealed to keep the moisture in and stacked around the cellar for storage until the first Spring flower show. That way, we know they'll be cured and it'll keep the dust off :)

Wow..such responses and for the record... I AM addicted!
(along with growing my herbs of course).... since we're on a roll here.... about storing.... I have made my pots, left outside to cure and get watered down at least 10+ days, now have them in my cellar just on the floor .... I read where Club mentioned wrapping so the "moisture" stays in... should I be doing that...? Upon checking down cellar today, they "are" looking a bit dried out now

Thanx for all your comments and help.....

Luvherbz

Methinks the 28 days regarding tufa refers also to the time it takes to naturally leach the plant-harming alkalinity. So, iffen you are bathing the masterpiece it is curing stronger and also helping the leach process.

How about using painter's plastic or a $1 store shower curtains to create a "dust booth" in the cellar? You could use duct tape and wire hangers to shape the area and keep it sealed enough not to endander the furnace with dust....

Concrete can be cured to a hard state in three days at 70F. Commercially 7 days is usually considered finished, although it does continue to strengthen measurably for weeks, even months. Curing to 28 days definitely produces a tougher product. There is theoretical curing beyond that almost indefinitely but not really anything measurable.

At lower temperatures it is slower. At 50F you should perhaps double those times. Ultimately curing at 50F will give a stronger result than curing at 70F if you follow the rules and keep it moist.

I'm assuming the same rules apply to hypertufa as to concrete, it is the same chemicals doing the curing after all.

If I've been raising a lot of dust I often 'wash' the air - I have a cheap water mister, the type that gets pumped as you spray, to produce a very fine mist. I walk backwards round the studio spraying the air with a very fine mist(right up to the ceiling). Dust particles can stay airborne for 4 hours, so I'm very keen on masks and air-washing.

I've always been very worried about dust - my great-grandfather was a sculptor, and died at 42 of silicosis of the lungs.

My indoor trick is in regard to cleaning tubs and tools. I can't rinse them outdoors because the water is turned off for the season. Rinsing them indoors would, over time, wreck the plumbing. My solution is to put a half garbage bag (one layer) in the tub, mix the cement in that and when I'm finished, I just roll up the plastic and toss it in the trash. I also have 2 buckets of rinse water available. One for rinsing gloves and tools and another just for rinsing my hands. I empty those outside whenever I feel they're too ugly. Other times when I'm doing only a small amount of mix, I'll use recycled take-out containers or cut off gallon jugs that get pitched when I'm finished. Makes for an easy cleanup.

I am about to move indoors...my friends fixed up a basement space for me to use as a concrete studio.

All the water heaters are in this room though & have pilot lights (aka open flames). Does anyone know of any concerns with the cement dust & open flame? I know I can't use any flammable solvents or anything down there...

cement dust & open flame?
I believe the bigger problem is cement dust and your moist lungs. Better have a very good mask. I have done in past and the dust lingers. You have dust when you mix and dusk when you remove from mold and ruff up the finished product.
Do a search on this forum using search funtion "hypertufa dust", imagine it has been discussed in detail before.
Not worth it -

Mike