Thanks for the question, my recommendation is to use either of these methods:
1) Hold the bar of Bullet and the bar of Zoom (or Zoom graphite) together and touch the bars to the warm iron dripping a bead of wax all along the base, then iron in; let the mixture set for a few hours or overnight, then scrape and brush.
2) Touch the bar of Zoom (or Zoom graphite) to the iron to soften and then rub a thick coat on the base, then touch the bar of Bullet to the iron to soften then rub a similar coat over the Zoom and iron
in together; let the mixture set for a few hours or overnight, then scrape and brush.
If the temps are very cold -- down around -12c or 10f, it would be best to use just the Bullet straight, without mixing with Zoom or Zoom Graphite and apply using with of the two methods above.
Enjoy your ride!