January 28, 2020 | Chris Blandford
Moving on to the fork. Steps:
1. Fit and braze steerer to crown
2. Shape crown, if desired
I begin by fitting and brazing the steerer tube to the crown. The crowns I’ve worked with are nicely machined post-cast; to this point, they haven’t required much fiddling to fit nicely around the steerer. (I was taught that the steerer-crown interface should have no play, but should be loose enough to allow the crown to slide down the steerer under gravity.) In this case, I merely cleaned up the outside of the steerer and the inside of the crown with 80-grit emery. (I was also taught to orient the emery "scratch marks" in the direction one wants the silver to flow while brazing. So, I do that with everything I silver braze, as shown here.)
Once cleaned up, I drill a hole for a pin that will hold the crown to the steerer while brazing. I use regular hardware store nails for the pinning, tapering them slightly on my belt sander so that they fit tightly when I tap them into the assembly-to-be-brazed. Also worth noting is that I allow just a small lip of the steerer to protrude past the bottom of the crown. When I go to braze, I’ll do so “upside down”. Having a little lip there allows easier feeding of the silver filler.
Finally, I drill vent holes if appropriate. This crown is hollow in the shoulders. I vent fork blades top and bottom, so these holes will allow the blades to be vented directly through the steerer. Some crowns I’ve used don’t allow this; those forks’ blades just get a simple hole, somewhere up near the crown.