"We sand between coats 320 takes about 4 coats there no way around it even with solvent"
In keeping with the spirit of Andrew's message, I must clarify for those newly venturing into pro-grade levels of finishing, 4 coats is not typical for solvent based finishes, and is plainly discouraged if you follow directions on any can of "pre" or "post" catalyzed topcoat.
Solvent based topcoats that employ an acid catalyst WILL CRACK EVENTUALLY if applied too thick, which is why going beyond 3 coats is flirting with disaster. These are cross-linking finishes that will continue to pull molecules together, and if dry-film thickness is exceeded, they literally tear themselves apart, given enough time.
And please understand, just because water-born finishes don't smell bad doesn't mean they're good for you - read the directions and wear a respirator, especially if spraying.
So ...
Point #1: AHA! solvent based finishes are not perfect either!!!
Point #2: Costs associated by increased volume and sanding labor is very wasteful, regardless the product being used,in my opinion.
Point #3: Just re-visited the MSDS sheet on the CAB Acrylic conversion finish I use - Yikes! I'd quit this stuff today if I could. (Hopefully a safer, high quality/ high performer presents itself soon!)
I welcome future opportunities to do myself and the planet a favor and try new products as chemistry advances, provided the results are in harmony with my quality and efficiency standards. I am required to run my business with this level of responsibility, as my clients are relying on me to be here for a good long time, ready and able to provide the quality and value they've grown to expect. This is the same for all the other passionate, talented craftsmen who've engaged in this discourse, and well beyond. I too am grateful this discussion was initiated - many very good points have been posted and should be weighed seriously by anyone wishing to advance their finishing processes.
If it was easy, everybody would be doing it!
jeff