I had to answer - I didn't want you thinking your question wasn't important but I never worked with thinset - planning on it - but I use GEII right now. It's hard switching over if it ain't broke - don't fix it.

Some will be answering soon.

I think it was a combination of using two porous materials. The concrete was taking moisture out of the thinset, and the clay was to! This would cause (I think) The thinset to dry out before it could cure properly.
I would think you'd need to dampen the concrete before applying the tiles, and mist the whole thing with water, and cover with plastic to keep moisture in.
I'd think the easier thing to do though, would be use silicone.
I'm not an expert by any means, just an opinion! ;)

I agree, I think the moisture got sucked out. I probably would have sealed the statue with cement paint. I have always painted mine before I started, but then I never used thinset, just glue.

Thanks for the help. Every time I go on here I learn something.

Is GEII a silicone?

I need to get some of that.

GEII Silicone caulk for windows & doors - I get the clear. I would also get at a big name store like HD or Lowes because you can get bad tubes but going to one of the bigger stores they move faster.

CarolAnn, According to my DH , I keep the GEII Silicone makers in business. I only buy mine at WalMart, and have yet to get a bad tube. It's much more convenient for me because I can pick it up when I buy groceries. I use it for everything. However, I am a very new novist at this so... I hope your son-in-law comes home soon. My baby (18 yr. old son and my only child) is graduating from Army boot camp next week at Ft. Sill, OK. He'll go to Missouri for 10 weeks of electrical training and then...? I'm really scared for him. I pray the our boys come home soon. And, I'll pray for your son-in-law, too.
Jeanette from Mississippi

I use thinset all the time I hardly ever pant or warter it down ,but using the clay could make a diff. I wander if she got the thinset that needed admix and used warter instead ..It would not hurt to wet it first if using thin set.I did these no water.

{{!gwi}}

I see these frogs, ducks, snails, etc. a lot here and I just wondered????--- are these concrete statutes or what under all the mosaics? Nanatricia, LOVE your frog!!!
Jeanette

That frog is cute. Is he cement?

I'm going to use GEII Silicone on my next outdoor project.

Thanks Jeanette, I pray all the boys will come home soon too.

Weldbond or DAP would have worked well. There's no need to paint your statue before gluing.

Hello, Perhaps seal the concrete . Wetting it down will not rectify this problem. Use 1 part PVA glue to 3 parts water. Paint over the entire surface with this mixture. Even seal it twice one first coating dries. Most pourus surfaces must be sealed before mosiaced. Remember if the finished piece it to be outside make sure you also seal your grout .Also there are lots of books and manuals on Amazon for mosaicing. Saving time and money with adequate information will help in making this art form wonderfully enjoyable.
Godd luck ~
Enjoy ~

I have many many pieces of concrete mosaiced outside in hot humid weather all the time.Only would use thinset on concrete and have never even sealed mine.I have used terracotta tiles also with no problem they are mainly clay..Maybe what Bama said she bought the wrong thinset or it was old???I buy the kind you only mix water with.they sell some at lowes and hd you have to add a special liquid to??Should say on her bag's and what kind of tiles did she use?From a tile place or what?

She used some stained glass tiles and some tiles like Kitty used on her thread called "Jerusalem Pots". They came from Hobby Lobby. The stained glass tiles seemed to stay on better then the pastel tiles.
She's very discouraged but I told her that making mistakes is a part of learning and we'll get it right next time.