Thin Wall PVC

How critical is it to use thin wall PVC?  I could only find schedule 40 
pipe in six inch diameter in my area.  I simply sealed the pipe with more 
coats of urethane than I probably needed.  The rest of Richard Quicks 
instructions were followed to the letter.  

About spark gaps... I constructed a rotary gap electrode disk yesterday.  
I used a hardened steel plywood saw blade which I grinded the teeth off 
of.  I then drilled holes in the blade and mounted sixteen electrodes.   
The electrodes are made off threaded rod,  mounted with 1/4 inch nuts to 
the disk.  I rounded the ends of the rod to provide a better gap 
surface.  I then sealed the nuts in place with two part epoxy to prevent 
loosening during the expansion/contraction during heating.  The whole 
disk will be mounted to a AC motor with variable speed control.  Will 
this gap system be sufficient to quench a neon system, or should I wire a 
cylinder static gap with it?  Any help will be greatly appreciated!