Actually it is less than that ...you are short 4 lines to make 24 hrs but if you think about it you can go between the lines. That would make it just a tad bit over and hour and that is splitting hairs.

Really it is more of a guide than anything.




Dave---I dunno so I would say e-mai him and ask---his replies come back by next day.
Making one out of vynal tubing I would think it would be hard to see unless you are on top of it.
Kinda hard to say without actually seeing one.