Transtar is not a bad product. As MPandC mentioned above, when using epoxy as a primer you can experience adhesion problems and it does not sand well, it is like he said it gums up your sand paper. The etching primer has excellent adhesion to bare metal. If you look on the back of the Transtar can it should show an option to mix the epoxy as a primer or as a sealer. I would save it for use as a sealer. I hope this helps.
