Morning and welcome to the mix!
I'm doing a fair crack of spheres,and most of them are of the water feature type,going from a basketball size to 32 inches.I've so far done two types of bases:pedestal and disc.The first I did as a prototype for our front door feature,using Mymud and mesh over styrofoam.So far,works well.The other is one that's easier to do,but heavier.For them,it's a matter of basic 3:1 mix,colour,pour into a round mold of appropriate size,then make the top surface concave.I use a bowl(stainless mixing bowl) to smoosh down the middle.Let set,cure,and away you go!I believe others,including L&L,do this style.
A note on the water feature aspect:For the best look,the cord should pass THRU the ball's side.This is part of planning it as a water feature;otherwise,you have a cord disappearing into the mouth of the ball,giving the feature an incomplete look.I saw a very nice water feature at a local garden centre recently.Nice look,but,that cord...!
What I've been doing(I love adapting things!)is building in a hole in the side,above the waterline if possible,using a doohickey that Home Depot would carry.If you've ever built a computer desk,you will recall that round plastic insert that you pass your cords thru.You get that,along with a cover plate(comes as a package),and cement around it on your ball in your first coating.When you're done your concreting,you have a plug-size hole to put your cord(s) thru.Silicone the cover on(use aquarium silicone if possible)on the INSIDE of the ball(the doohickey will be facing that way) and you're done!If you want it underwater,same rig but perhaps(not used it yet but will be)fill the rest of the hole with a quick curing concrete,the kind you can patch cracks underwater with.Coloured as required.This does commit your water feature to that pump.Any breakdown of the pump(if the motor burns out)you're hooped!
Good luck with your balls.As Mel Brooks said in SpaceBalls"May the orb be with you".Or,something like that...

Cheers from here
Rick

Hi Rick! Thanks for the info! I sorta figured that I could use a column that had a top with a concavity (is that a word???) to hold the sphere. I found a plastic bowl that will work for the smaller spheres as the bottom is indented already.
Great idea for the water feature. Right now I just want to set the larger sphere on an angle..fill with water and put a couple of feeder goldfish in it. The hole in the side would be great as then I could put an air filter for the fishies! This feature is going to replace a wine barrel pond in my sunroom.
Ok so I am going to try and put a picture in this message. If it doesn't work it's back to the drawing board and I apologize in advance.
{{gwi:70806}} and {{gwi:70807}}

Great colours on your mushrooms!Modern Masters??Good eye for the colour mixes.Do you use a plastic bag liner for the wrinkling effect?
It's so good to see other people who need to seek therapy about their addiction!
Cheers from here

Thanks for the compliments! I don't think that therapy will help any. I seem to have a bit of an addictive personality and whenever I try something new it sorta takes over. The concrete is just the newest flavour and in six months it may be something completely different. Oh well..gotta keep those hands busy.
The paint is a metallic rub-on that I have had for a long time. The name on the lids has worn off so I don't even know what they are. I do know that they are a wax based product so I am hoping that they will stand up to the weather. I have had one mushroom outside in the full sun and the rain for the last few months and there doesn't seem to be any loss of color or intensity.
I do line the molds with plastic to get the wrinkled effect. Here is a picture of a shroom done by lining the mold with bubble paper...I really like this effect.
{{gwi:70808}}

Great mushrooms! Love the painted ones. I have used the bubbble wrap for a trough, but hadn't thought about it for a mushroom - very kool!
Any pics of your spheres? I so want to make one.
Rick - where can we see pics of yours?
Laurel

Dolltrek - I love the mushrooms.... it amazes me how everyone comes up with new interpretations of ideas all the time.
I, too, found some old metallic wax rub ons in the basement! Mine were called Lustre (yes, spelled that way) something... in case you want to find them online to buy more. Mine made wonderful leaves but I thought the colors faded pretty fast outdoors. I hope you have better luck.

About your question as to attaching spheres to stands... You can have pretty good luck just sitting them on things. Here are some photos of the kind of plant stands I get (when they are on big sales!). When you sit them in plantings, they completely hide and can give the illusion the sphere is floating. I have never had one fall off yet - even when bumped.
click photo to enlarge

{{gwi:70801}}Â Â
{{gwi:70803}}Â Â
{{gwi:70805}}Â Â

To attach a sphere to a column, I would try drilling a hole in my sphere and concreting in a 4 or 5 inch section of copper pile (3/4 inch dia). Then I would drill a hole in the column and concrete in a matching piece of 1/2 inch copper pipe sticking up out of the column. That should give a solid, but removable connection. I'm sure other people will have better ideas.

Laura

Laura: thanks for the tip on displaying the spheres and attaching them to columns. I like the idea of the sphere appearing to float in the garden!

Laurel: I only have pics of the first sphere I made. The sphere itself has been finished but the little stand I have it on has not as of yet. One rule I have discovered is that the degree of durability of any given object is in direct proportion to the degree of dislike one has of the object. Having said that I guess the finish on this sphere will last forever cause "I don't like it!" It is just a tad too garish for my tastes but hey..got one finished! I tried putting a plant that has purple tones in it but it really doesn't work. I may rip out this plant and replace it with something white or pale pink.
{{gwi:70812}}
{{gwi:70813}}

I can see why you put that plant in your sphere. I think of that as a plant with a much deeper purple - almost blackish purple. It should have been stunning. Oh well, that is the story with gardening! How about a bright chartreus sweet potato vine plant??
Laura

Laura: I may try that as I have some growing on the retaining wall at the side of the house. By the way, I just wanted to tell you that I love your spheres! In fact it was seeing your leaf sphere that provided the motivation for me to try making one myself.
Laurie