Applying the Polyurethane

The polyurethane coating is required to hold the windings all together and prevent electrical breakout.

Winding is done.  Wire is up to about 1/2 inch from the ends, and then spirals onto the end caps.
Gear motor slowly turns the coil to speed application and reduce drips and runs.

12" floor applicator is used speed up the task.

Dip, drag, dip, drag, dip, drag.......

Taking too long.  Just dump the stuff.

Dump multiple coats over several days.

This mess needs to be spread out a bit before drying, but will be just fine.

Done.  About a gallon of polyurethane.  Looks great.
Final weight: 50 LB

Now is a good time to square up those ends and remove poly-slop.
A table router combined with the winding jig works great.

Compared to the big coil, the HUGE coil is, well, HUGE.