because once epoxy sets, it is there to stay.
Regardless of gun type, a disposable filter should be installed on
the end of the air hose where it attaches to the paint gun. This will
ensure that moisture from inside the air hose does not get in the
gun.Self-etch primer and 2k urethane
Self-etch primer and 2k urethane primer go hand in hand. Self-etch
primer will adhere directly to bare metal and works well on aluminum
in addition to steel. Unfortunately, self-etch doesn’t have any filling
capacity, so it has to be followed with a 2k urethane primer for “build.”
There’s a lot of variety in self-etch primers as far as mix ratios go.
Some are one to one, some are two to one, and a few are four to one. Be
sure to get a technical data sheet from the paint supplier that clarifies
the mix ratio for the self-etch primer. Since one to one is pretty common,
that will be the example here. Simply mix the self-etch primer one to
one in a mixing cup and stir it well. There’s no induction time and
mechanical agitation isn’t as important as it is with epoxy primer.
Once the self-etch is mixed, strained and in the gun, it is ready to be
sprayed. In most cases, self-etch primer is thinner than any other primer
and seldom gets reducer. Because of this, it will use a little less air
pressure than epoxy or high-build urethane. One good coat with about a