I'm trying to put wax/ Clear coat   on my bass to cover an awesome design so it won't wear off and  I don't have a clue of what would be best...The Thicker the better...Thx to ne 1 who can help

The thicker the better?
To my knowledge (admittedly not complete) that's not always true.
Correct me if I'm wrong, but isn't there an issue about restricted vibrations with too much/some kinds of finishes/wax/other surfacing products?

hmm did you put the design on over existing paint/clear coat?  Wax probably won't protect it very well... and using regular furniture wax is not good for some guitars.. plus some waxes can yellow and cause cracking of some clears (mostly lacquers).

  I would look more into sealing it with a clear coat of urathane or some other clear cover..if you put the design  over existing paint and clear coat, you will have to be careful cause sometime putting certain clears or sealers over existing clear/sealer coats may cause the original to buble or lift (I have heard of this but have know actual experiance or first hand knowledge).

If it was me, I would take it to someone who repairs guitars, and just show it to them , ask them what they think. They are used to messing with matching paints and recovering stains/clear coats back to match original..

i agree with oldies..thicker is not better. it will alter the tone and sustian of your instrument.