ORIGINAL: Sport_Pilot
Heck, one can wet sand it to ''leak'' the pigments with nothing other than cold water!
If this is what I think you are saying you may not be letting the paint dry enough before sanding. If fully dry you will only have a dry powder from the lacquer that will not bleed the color.
The Duplicolor automotive acrylic lacquer I've been using has a re-coat time of 10 minutes and a "full cure" time of 30 minutes in prescribed weather conditions. One can clear coat this paint after 30 minutes. One can literally see the solvents evaporate as the paint dries. After 15 minutes, the paint is hard, dry and yes, "dusty" to the touch. With lots of humidity it takes a little longer but not significantly.
The area that was painted with lacquer was allowed to cure for over a week at 20 deg C and 50% humidity (my shop). I don't think that paint would cure any longer even after 24 hours but to be absolutely sure I left it anyway while working on other aspects. Even so, when wet sanded with 1500 grit, the paint will leak. In fact, this is the case with all the paint I used including epoxy enamel and acrylic enamel. After cutting throught the top gloss coats of the enamel, the wet sanding evidently cuts into the colour pigments and it will leak color into the sandpaper and water bowl. It just makes sense. If there is no color in the water, then one isn't sanding color paint pigments but rather clear coat layers.
In any event, the beauty of the wet sanding is the smooth silky feel it leaves allowing subsequent layers of paint to flow on equally smoothly. Of course, one then has to provide "grip" (i.e., primer) for some of it but it does build up nicely.
ORIGINAL: Sport_Pilot
If the paint has a retarder it could take as much as a week to dry that much. But most spray can lacquers only have enough retarder to prevent moisture from fogging in average humidity, this causes the paint to discolor.
I doubt any lacquer would take upwards of a week to dry, it's just not chemically engineered to do so. Of course, if there is a lot of retarder in it as you mention or otherwise has clear coat pigments blended into the lacquer recipe, that's another story. Hard clear coats take much longer to cure than straight lacquer.
Paint such as Lustrekote (and I only keep referring back to it because it's a well known paint due to it's MK covering
match) which is acrylic lacquer based has other clear coat chemicals in it to dry to a "thick" glossy finish. If one were to sand through those top coats though, no doubt this paint would leak too. In fact, I know it does as I tried it on a test board a week ago or so.
But the "leaking" is not an issue. When wet sanding, provided one hasn't allowed the leaked paint to re-settle on to the model for too long, it will wipe right off with a clean damp rag. I found that using warm soapy water is nice on the painted surface while cool water is preferable on primed surfaces. The model can then be wiped down with denatured alcohol for a chemical and grease free surface for final graphics and top clear coat.
David.