demaris, I LOVE it!! GREAT job! Is that glass? What kind is it?

Your tufa will reach full cure in 28 days, keeping it damp for at least a week is good. If you can, drop the whole thing into a bucket of water for a few days, and you should be good to go. It's a lot less work than misting & wrapping.

Well done!
~GardenChicken

>The 1:1:1:1 mix with sand, perlite and vermiculite is pretty heavy - I thought it would be lighter than that.

Demaris,

Believe me. A traditional concrete mixture in the same sized mold would be considerably heavier than your tufa mix.

Make yourself some test pieces with the same mold (margarine tub, etc.) and different recipes from the FAQ and be sure to make a "Quikcrete" sample for comparison. Not only will you get an idea of how much lighter tufa is compared to regular old concrete, but you will discover that the less sand you use, the lighter your end product will be.

Also this will give you the means for object lessons when people question your sanity in moving away from tradional concrete applications and recipes. Drop a true concrete sample in their hands then a 1:2 perlite or vermiculite sample in their hands. Object lessons are quite effective.

Your samples will also give you an idea of how well your recipes turn out in the long run so you can tweak them for your area/humidity/heat. The samples are also great for experimenting with stains, paint, etc.

Congrats on a great geodic-looking ball. Good job.

Jo

Thanks for the compliments! AND the great tips. Into a bucket he goes as soon as I get home from work.

I will definitely make some samples. If I had done that before, I wouldn't have had 2 failed batches already.

That glass is from a glass replacement shop - it is broken auto glass, and isn't even sharp. I took them a cat litter pail and said fill it up, I'll be back. I got that idea here on Garden Web, don't know who to credit for it. I hope after the ball cures, I will be able to clean up the glass so it sparkles, and if too much falls out of the holes, I'm going to epoxy some back in - is that cheating? :-)

If you add a little sand blasting slag or sandblasting to your recipe in place of sand the entire ball will sparkle.:)

demaris, You can use a long handled spoon to place the glass pieces in your glass globe. You can buy reuseable molds or cut in half a hard shell rubber play ball and duct tape the two sides back together. You fill both halves then tape the ball together. It will be easier to place the glass in a two part mold. If you want it lighter cut down on your sand. You can decrease to 1/4 part instead of 1 part. You should use some sand in your mix for strength. Your sphere looks great. Billie p.s. I love "decant".

MuddyMesaWoman, "Quikcrete"? Are you referring to QUIKRETE? Quikrete is the name of a manufacturer of many cement products not a particular product. Just don't want demaris confused when they go to buy and all the bags say "QUIKRETE". Billie

Here is a link that might be useful: cement products

Peat may confuse me but not cement products! My DH and I have been fixing concrete stuff for a long time. Even to mixing bags on our 2-story roof and pouring a cap for a chimney.

I had to laugh at the young guys at the home center when I asked for Portland. They didn't think I knew what I was talking about, kept trying to steer me to Sand mix. Then along came an older guy, and he right away says, are you doing hypertufa? Connection!

Billie Ann wrote:
MuddyMesaWoman, "Quikcrete"? Are you referring to QUIKRETE? Quikrete is the name of a manufacturer of many cement products not a particular product. Just don't want demaris confused when they go to buy and all the bags say "QUIKRETE". Billie

Yup. Quikcrete. Regular old gravel and sand for aggregate Quikcrete pre-mixed concrete mix in a bag. If you don't have any Quikcrete, pick up a "project" bag. They are 40lbs each and only cost $1.97 (here.)

Either that or find an old chunk of concrete walkway, wall, etc. that's been dumped and make comparable sized samples of the other recipes to make your comparison.

It's an eye-opener.

Tah!

One tiny lesson learned:
If the ball has an air valve it will leave a tacky looking hole in your project.
You'd think I would have thought of that first! tsk tsk