I found this thread googling and had what appears to me the same issue with nasson urethane.
I don't believe the answers here, any, were the reason. I think my problem was I would try to apply another coat 24 hours later of clear. This would lift the clear of day before that was applied 15-60 minutes after base color as manufacturer recommends. The problem came because another entity would turn down thermostat after I left. I think, I needed 24 hours of 70 degree heat so film could fully bond before hot topcoat wouldn't lift the previous coats.
Most pro body people wouldn't run into this as the pro is interested in production and wouldn't hit a car two days in a row, and would have better climate control.
Last edited by degarb; 03-18-2011 at 10:21 PM.