Crystal FX half round

[blabla]

I'm a car painter from germany and I have a question.
Please watch this video.


http://www.youtube.com/watch?v=H-mFq...eature=related

Here in germany we mix our Crystal Fx on our own with urea, water and alcohol.
Then the crystals grow straight. But in the video they grew half round.
Can maybe someone explain to me, what kind of trick is behind this half round growing?
Maybe round sanding? Or another additive?

It wold be very nice, if someone could help me

Thanx

 

[TAZ]

Interesting. I've tried the crystals before without too much success. I think it was just too hot down here.
So I wouldn't be much help to you. Good luck though!