How can I make a hollow, see-through sphere?


This is for an adaptation of a lamp. What I want is to cover the bulb with a large (little smaller than a basketball) sphere, so there will be a hole in one end. Light obviously needs to be able to shine through. My first thought was a resin of some sort, and a quick search led me to epoxy resin. Is this see-through? Can colour be added? Any other ideas?
Some early thoughts:
- In an inflated balloon, inject liquid. Rotate, thereby distributing fairly evenly, until liquid hardens. Cons: How long do I have to rotate this balloon? What if it pops!? (Could use a hard container...)
- Double boiler: Use two similar bowls, small inside larger, fill in between. Cons: How to get it even? Smaller bowl would float (weigh it down...) Not even close to a sphere

With your suggestions I'll do a few trials, possibly put out an instructable if something works. All suggestions are welcome (even if they deviate a little). Thanks!

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Re-design7 years ago
Your balloon idea was a good start I think you just got started thinking on the wrong site of the box.

Try blowing up a baloon to the size you want then painting epoxy resin on the outside. It's going to take a while and many coats but I think it's possible to get a winner this way.

It's going to be messy and take a while.

You can use 5 min. epoxy that stiffens in about 2-3 min's. and is solid in 5. It's not as strong as 60 min. epoxy but quite hard enough for your use.

It would probably help if you had a helper mixing while you were painting.

I don't know if a balloon is "epoxy proof" so do a test.

It is possible to buy clear plastic spheres. You could get one of those and "textureize" it to give the translucent quality to pass light.

But it'll mean more if you do it yourself.

Good luck.
P.S. You can get epoxy in clear and amber. You can add color (food coloring) but unless you mix up the whole batch at once your color is not going to be uniform but that might make a more interesting lamp anyway.

For anyone reading this Please read up on the highly toxic nature of resins (which will stick to anything ie you won't get your balloon out) Degrees in science and arts (Canal St. NYC home of former place with this products/molds so on).

funkrack (author)  Re-design7 years ago
I'll have to try that next time. For now, I found something that slid straight on, for next to nothing. Thanks!

I'm wanting to know if there is a way to make continuous glass hollow spheres for a filling with various sizes, maybe using air?

... carbon fiber even better!

What if you filled a globe shaped mold about 1/2 - 3/4 full and then inserted an empty balloon (one that is at least bigger than the mold when fully blown) so that when you filled the balloon with air it would force the resin up towards the opening. At that point, tie off the balloon. Once the resin has cured, pop the balloon and remove it and then remove the mold.
I dunno, the idea just came to me from reading other people's complicated suggestions and I thought there has to be an easier way! Anyway, I'm going to give it a try since my whole reason was to find a solution just like you. This is an old post I'm replying to and you will probably never read it but to anyone else who comes along and reads this please let me know if you have any better ideas than the ones suggested here so far. Thanks!
I will post my results!
The attached picture shows two hemispherical, transparent, smoke-colored, acrylic, security camera domes held together in my right hand.

I got them from a surplus-monger in the Former U.S. Some place in Texas, if I remember correctly.
http://www.bgmicro.com/ACS1454.aspx
http://www.bgmicro.com/ACS1470.aspx
Although that's probably not important, as there's probably more than one retailer that has these things. And you probably find them in other colors and sizes too, if you look hard enough.

I hope this does not ruin all the fun you had planned for fabricating such an artifact by yourself.

smoke-clear-sphere.jpg
funkrack (author)  Jack A Lopez7 years ago
Thanks for the suggestions. I was very fixed on making something myself, but then found something for €1.50 at the local flea market this morning, much like in the link you provided.
Here's the image of how the lamp looks for now. Not really happy, but I think a different type of light bulb will do it. (and the so-so shade that came with it...)
IMG_3019.JPG
jtobako7 years ago
Cover the balloon with clear tape.

Glue up a sphere from clear plastic (like gluing up a map into a globe).

Use two plastic bowls.

Use a vacuum former to make two halves.

Make an oriental paper lantern in a globe shape (usually a wire or bamboo splinters tied into a frame and covered with tissue paper).

Most lamp shades are translucent, so paper mache with tissue paper or just few layers would work.

rickharris7 years ago
If translucence will do - PVA glue and some white wool. (on the outside of the balloon.