What method did you use to apply it? Just pour it on, let it settle/cure for a day & a half, and sand to fit?
Exactly.
Also, when you say it levels itself, what does that mean? Does it settle across the fretboard's radius, or does it settle flat, as if the bass had no radius? What is the main reason for sanding? Leveling the finish? Gloss?
Any pouring swirls or uneven spots will settle to a uniform level and will pretty much follow the fingerboard radius. Along the edges of the board is where you'll get high spots or a ridge which is the main reason you want to sand... however it's also necessary to get a nearly "perfect" surface along the entire FB with less than a thou runout. You then want to buff it to bring back that high gloss.
Also, is this as volatile as some of the other "toxic" laminates? (eg epoxy & ca) What do you do to pretreat the wood before applying?
It has a plasticy smell... if you know what I mean. You know, that nauseating plastic smell that old style I.V. bags or childrens toys had. So the smell isn't going to give you a 5 minute episode of phosphenes or get you high but it isn't something you'd want Renuzit® or AirWick® to replicate as an air-freshener either. I'm a huge fan of using acetone (not fingernail polish remover, which has additives) to clean the surfaces of things that it won't dissolve. When I was still experimenting with EL I poured some on strips of pine, oak, cherry and walnut after cleaning their surfaces with acetone. Once the EL cured I tried pulling it off the wood but chunks of the wood came off with the EL which had the consistency of super stiff taffy... almost like working with borderline molten glass yet stiffer. Kind of hard to describe, really.
)