sex link question.
If you breed your Welsummer rooster with the Silver Laced Wyandottes, you should get sexlinked chicks. This does not mean that you won't get male chicks, though. It just means that you will be able to tell the males from the females early on. The differences between the males and the females might not be very clear at hatch though. It can take some practice to decipher the male silver-based down from the female gold-based down. As they feather in, the males will become much more obvious. They will be the ones that are mostly black and white. The pullets will be unmistakably golden/red/brown.
If you choose to hatch eggs from your flock, you need a plan for what to do with all the boys that might hatch.
I hatched a few black sexlinks from my Easter Egger rooster and my Barred Rock hens. They grew very fast, much faster than I expected them to. They were nearly completely feathered in by 4 weeks old. They are about 6 weeks old now, and are big enough already to start introductions into the adult flock.
Since Wyandottes and Welsummers are both fairly large breeds, the male chicks will likely be ready for processing by 12 to 16 weeks.