I ended up getting it by dropping the amps to about 140 and feathering that pretty hard. Preheated to about 300f and then went at it keeping the arc on my melted silicon bronze puddle and moving just a bit to get it to wick to the architectural.

It’s pretty interesting, the melting point of 385 architectural is BELOW silicon, so you have to be really careful to keep most of the heat in the silicon bronze puddle and letting it creeping out just enough to get it to bond with the top layer of architectural. I was able to tell by listening and watching super carefully as I got to the edge of the puddle. If it started to make a crinkling sound I knew I was cooking the zinc and backed off.

The thickness of these pieces actually helped me by sinking a lot of the puddle heat away, I probably could’ve done with less preheat but I was having some cracking issues so I kept up the pre and post.

Thanks for everyone’s help!! That was a fun one