Thought I'd pass on my ruminations about ball construction.I've now done 2 of my largest,4 of my medium and 3 of my small,and one itty bitty one today.What I've determined so far is that for the first coating,I'm going to stick with silica fume.I get zero slump and no hassles.Metakaolin,on the other hand,has some slump that I'm uncomfortable with.In saying that,however,I should point out that it makes an excellent 2nd(roughly same thickness as first) coat when it has that underlying concrete already on the ball.The truer colour that's available(using colourants added to mix)through the use of MK is undeniable.So far,the two balls that are water features show no leaks(but hellacious evapouration!)and neither were waterproofed,just painted with a latex/water mix.My experience has told me that leaks show up early to the party,so again,we're good on that here.

I would recommend that anyone playing with Quickwall or Mymud ensure that your balls are tight(........!),meaning slightly overinflated.As you're not using them for exercise,they can take more pressure.The extra air makes for a hard work surface.The concrete work becomes much easier.

If you're making a ball,think about a base for it to sit on.I'm making mine fairly heavy(conventional 3:1 mix),and,as additional security,I'll be applying a bit of silicone to the area where the ball sits,so that there is some"stick"involved.

That's all for the moment.I see that there is another thread about smoothing the coating on the ball.I'll be reading through those and working a little on that on my baby ball that I've just completed.

Cheers from a warm here!!