What type of Van De Graff emits external bolts?

Does the 10 dollar Van De Graff on Ebay emit external bolts outside the sphere or just inside?

If I cover it with a material, and cut a small hole in the material, will it have a directional beam?

A device separate from the Van De Graff,
Is there a way to alter the polarity of an object at a far distance? (for example, giving a cement wall a high negative charge from 50 miles away?)

$10 ???

Yes you can cover the generator ball with a material, even a dielectric. The electricity will find a way out. But from there it always heads to the closest path to “ground”, Earth. You cannot direct it except by ensuring that you target is the only thing around.

To be clear, the arcs will go outside the ball? Because some van de graffs the arcs never leave the ball, you just put your hands to the ball and the arcs never go outside the ball. So what type of van de graff am I looking for on ebay that has a name hat tells me the arcs go outside the ball?

There has to be some kind of way where you can alter the polarity of an object at a distance?

The “arcs” are merely the effect of the electricity going through the air. A higher voltage with a grounded target will cause an arc to leave the generator ans strike the target. If the voltage is not high enough, there is only a tiny bit of leakage that can only be seen in the dark. But that leakage is still enough to make your hair stand out.

Well Im afraid the 10 dollar one on ebay will bust if I get the voltage high enough to leave the ball.

There has to be some kind of way where you can alter the polarity of an object at a distance?