I have had the best luck with Aero-Gloss (model airplane dope). I apply two coats (thinned) and then spar varnish until smooth. I also use the Aero-Gloss for fly head cement as it is cheaper than commercial head cement. Haven't had a problem with white/opaque wraps (.....yet!!). (Tom Mohr)
I had the same experience with lacquer and color preserver. Both resulted in cracks at the butt ends of the foot wraps as well as the crowned end of the ferrule wraps My supposition is poor adhesion between the lacquer or color preserver and the varnish underneath. The responses I got when I mentioned these problems were:
STAY AWAY FROM COLOR PRESERVERS, USE VARNISH, ONLY!! (Al Baldauski)
In the previous post I neglected to mention I used a polyurethane gloss spar by Helmsman.
So many people have said lacquer preserves the original color of the thread, and I guess it does, but not with all colors, at least in my experience. The pesky problem wraps I spoke about were done in a medium tone olive green silk (sometimes called Granger Green) with occasional red accents. With these colors I can't see much difference between wraps done with lacquer bases and those done with straight poly. The lacquer I used did not help to retain the original thread color. Maybe it does so with lighter color threads. For darker colors, and even a relatively light olive, I can't see any reason to use lacquers. And I'm guessing the only reason production folks did is because it dries so fast and is therefore inexpensive, although prone to blowing up the occasional factory. (I was able to apply 3 coats in one evening without explosive side-effects) Otherwise, it seems like a terrible choice for a wrap cover. It cracks and does not hold well to poly varnish. Maybe there are varieties of lacquer that work better and are not so hard (and prone to cracking) like Aero-glass but I can't see a reason to use the stuff on new rods. It's an old tradition that just doesn't work very well.
I have tried wraps in gloss poly and satin poly and in these cases didn't see much difference, but in this instance I was using two different brands (a Helmsman gloss poly and a Minwax satin poly). They both are very durable and work well; neither preserves the original color of the thread. (Bob Milardo)
I'd offer the following experience: After wrapping apply 3 coats of Pratt and Lambert R10 gloss varnish directly to the wraps only and then dip the entire rod with 2 or 3 more coats of the same varnish. Now mind you, the thread will change to a darker color when varnished so make a test wrap first so you can see the final color. If you wish to have the thread of the wrap not darkened when varnished but stay at the original hue then use 2 coats of U-40 Color Lock2 on the wraps first before varnishing. The U-40 is sold by Angler's Workshop in Woodland, Washington. No problems noted using this system. (Ray Gould)