IT FLOATS. Until it gets soaked then it hovers.
Paws

Here is a link that might be useful: It Floats

Paws I was watching a PBS show about giant water lillies that look like huge green flan pans.
I think I might try a vermiculite and peat version of one of those but only about a foot across.
Carving it will be a challenge though.
I'm planning a small pond in the future and that would be about the right size.
A nice fat frog to sit in the middle would make it perfect.

HEY! Don't tell! If this is a tufa challenge, ya gotta be verwwey vewy quiet. We're out huntin' floating tufa....OK, count me in... I'm saying no more.

Does it have to stay afloat or can it sink after it has soaked up water?

Amy

Hi Amy
I've already got a couple emails asking for rules.:)
I never gave it much thought, but originally I was thinking of a tufa pond ornament that would stay afloat.
I would like to know what everyone else thinks.
I had a question about acceptable recipes and sealers. If adding styrofoam was OK.
I was thinking as long as the makings were mixed in cement like regular tufa you could add anything, but attaching a big chunk of styrofoam would be kinda cheating.:)
I think sealers should be OK.

But whatever everyone thinks is cool with me.

If I had some of that fancy Perlite that doesn't soak up water this would be easy.:)

I read years ago that perlite does not absorb water. It holds water on its surfaces.Vermiculite on the other hand absorbs water like a sponge. Using larger perlite should help your project float. Maybe you could sift out the small stuff. Ever notice when you water a flower pot with perlite in the mix, it always floats to the surface? Could you just skip the sand and add peat moss to the vermiculite and portland?

Styrofoam should be okay as long as it isn't visible.

NO STYROFOAM PONTOONS, GUYS!

Sue

Well I guess my plans for a tufa float plane are out.:)

The only incentive I have to complete anything is if it's common knowledge.
I'm easily side tracked by experiements that never turn into usable stuff.
So I'm going to go out on a faux bois limb here and post what I'm going to attempt for this project.
It won't be tufa, so technically it won't qualify for my own challenge but I'm going to attempt it anyway.:)
I was going to make one of those giant lilly pads but that would float even out of regular concrete, it's like a dish. Then I though about a half sunk aligator but I have no carving skills.

I've decided to try to make the giant lilly pad flower itself. I think they are very cool.
Hopefully a nice big pinky white bloom out of light weight concrete and papercrete. Could be tricky considering I don't use paint.
Blending pigments to give a smooth transition from pink to white is going to be a challenge.
Can't be that tough to make the flower, just a bunch of pointy things sticking out of a base.:)

I'm not sure if a time limit is needed but I'm going to need at least 6 weeks, maybe the end of july.:)

Considering I've never seen a real lilly pad flower I have some homework to do.:)

Colored craft paper just doesn't work in papercrete.
I can get the color to show nicely but it fades out rather quickly.
I'm wondering if other types of colored paper might work better.

Construction paper is infamous for fading. You might try some of the acid-free papers that scrapbookers use. They're supposed to hold color.

Deb

Thanks Deb
I'll try to find some in red or dark pink.
I've been sitting here forming those spike petals you see on lilly pad flowers from a paper slurry and portlands.
I'm trying to get a petal that starts rather dark pink at the bottom and fades to white at the top without using paint. I want integrated color.
I can get one to look great wet but soon as it dries the color is gone.

I've been working without gloves so right now my fingers don't feel so good.
I have to get some of that liquid glove.:)

It has to be tufa? Not concrete? Concrete boats float. I think that tufa boats are probably called submarines.

Sue

Sue, whatever floats your boat, is fine with me.:)

I had imagined an object made from a recipe that would float regardless of shape but a boat is OK too.

I've decided on a tufa base using styrofoam beads in place of perlite with just enough peat to make it legal.;-)
No real strength required so this should work.
The flower petals will hopefully be papercrete.
This is actually pretty easy but very time consuming making a gazilion petals and trying to get the colors the way I would like them.

I wish I could find a really good picture of this flower.
I'm trying for that giant lilly pad flower look.