Great topic! $20 for that little bottle is a lot of money!
As a beginner Zainoholic I used Z-1 with every application. Why not, it was only $8 then. When ZFX was introduced I just had to buy some and was shocked when I opened the box and saw the tiny bottle! Some of my dismay disappeared when I talked with Mr. Z on the phone and he assured me that I only needed to use it for the first coat of Zaino and every tenth coat or once every six months to a year thereafter. That made the price a lot more reasonable.
He also told me that ZFX would do two things: improve the both the bonding and the curing rates. After using it for many layers (every 4-6 coats) I decided to do some testing. Small (maybe 6� squares) on my rear deck. Only Z-2 (or maybe Z-5, don’t remember now) on one area, Z-1 topped with Z-2 on another, and Z-2/ZFX on another. Started timing and doing the “finger test�. I don’t remember the exact times now, but they each passed the finger test within a couple of minutes of each other, and as I recall it took about 25-30 minutes in direct sun on a cool (maybe 60-65) day,
Then I did some thinking about it. There is no way to tell how much of the product actually bonded to the surface if the surface already had a good Zaino base on it! Same thing applies for checking the curing time - how can you tell if a coat of Zaino was really cured when you add a second or third coat?
My answer to the problem is to follow Mr. Z’s guidance for the most part, but usually on the conservative side. When starting from bare paint I use Z-5/ZFX for the first 3-4 layers, the every few (4-6) layers there after. When dealing with a small spot repair I always do two back-to-back Z-1 & Z-5 layers and then repeat the next day.
More opinion: I think that Z-6 to some extent acts a little like Z-1 in aiding bonding. Misting with Z-6 just before applying Zaino gives slightly better results that if the Z-6 wipe was an hour earlier, and it gives much better results compared to not doing any Z-6 wipe down.
In the past couple of years I’ve gone through several bottle of both Z-5 and Z-2 and three bottles of ZFX and had as many as 30+ layers of Zaino on my Jet Black paint at any one time. But now with the help of counseling, therapy, and Prozac I’m overcoming my Zaino addiction!