Pitting problems

[nicks creative stuff]

Hi all,
hope you’re feeling festive if that’s your thing… I’ve fused this 1.3mm sterling silver wire with borax for a simple look cuff…. However after cleaning back I found fine porosity or pitting…. so a couple of questions to you experienced sort…. not sure what went wrong any ideas?… and can I somehow flood the ends of this bracelet with solder to fill some of the holes, giving me an opportunity to clean back for a better look.. thanks for any help…Nick