View Single Post
  #1  
Old 07-06-2019, 03:09 PM
Josh Bernbaum Josh Bernbaum is offline
Registered User
 
Join Date: Feb 2009
Location: Brattleboro, VT
Posts: 650
Josh Bernbaum is on a distinguished road
Weird melt results..

Sorry, didn't know how to properly title this thread, but I'm super confused..
I've done lots of melts over the years and I haven't seen results like this last one I melted a few days ago. I've been doing phosphate melts lately, 5 total, all mixing in with the SP Plain batch (no erbium). And I know, calcium etc, but I have been getting decent results for the most part. I'd been struggling with the fit but on that 5th melt I finally got it to fit the SP w/er clear I melt also.

Fast forward to my most recent melt this week, where I just wanted a transparent copper blue. I scooped out as much as possible from the bottom of the pot before charging this mix that was the SP plain with 0.77% black copper oxide. It's a gas furnace, my crown is in good shape and my melt times and temps were similar to what I've always done for melts like this.

I've done many, many ionic colors this way over the years but this melt was full of 'snot' that looked like semi see-through white-ish clumps. All throughout the 80 lb pot. My first thought was that, even though I'd scooped out the previous phosphate melt as best I could, that whatever residue from that was making snot in this melt. BUT, what's even weirder, is that compatibility was off, something I don't think I've ever seen with less than 1% addition of colorants to a transparent base. The ring cup I made didn't fare well on the saw, and the only info I could glean from it was that expansion of this blue might be low. My next thought then, is could I have gotten an 'off' bag of SP plain? Unlikely I'd think, as in my experience SP have been so consistent which is one of the many reasons I've stuck with their batch over the years.

Not sure what to do next but I've 'swabbed' the walls of the color pot today with some clear from my main furnace, scooped that out of the bottom, and I'm charging maybe a third of a pot of plain batch next for a 'rinse' that I'll scoop out to try and fully clean this thing. Am I missing something else I should be considering? Thanks in adv, and hope everyone had a good Fourth.

Best,
Josh B
__________________
www.jmbglass.com
instagram.com/joshbernbaum_glass
Reply With Quote