I applied a tube seam sealer recommended by my local auto paint supplier. When I primed over it the paint on the seam sealer remained tacky, almost as if it soaked into the sealer and made it soft. The seam sealer had been on my car for a couple of weeks and was firm and hard to the touch with no tackiness. The primer was just a high build primer. What gives? :confused:

You shouldn't have sprayed high build primer over seam sealer as it is harder & could develop hairline cracks. All seam sealing should be done after final sanding is completed prior to painting. Also, you want to make sure a expoxy or corrosion inhibitive primer is put down before seam sealing if any bare metal shows. Depending on how long the primer you have sprayed has been on you may have to remove it from the seam sealer area & start over in other sequence. Hope this helps, JOHN

What sealer and what primer were used?

Fusor 803 black urethane and Nason 421-19 primer