Weird things happening with Dark Turqouise

Harry · #1 2012-08-05, 12:52pm

Hi all,

I was working on a few stirrers with my leaf masher for a friend and noticed that the P-236 Effetre was developing some seriously weird dark circles around the rod right next to the gather. I made sure I was working in a neutral flame and then switched up to an oxidizing flame. Nothing much changed. Then I made the stirrer and, since I was already not gonna give my friend that one, I wondered what would happen if I went into a reducing flame. Turns out I got a layer of metallic grey on the leaf.
Then it got really strange. I put the stirrer in the kiln, made two more with light Turquoise 104 glass (those turned out fine), and then started the annealing. As you can see on the picture below the part of the rod that was never in the flame really darkened in the kiln (annealed at 970F for an hour). The original color was similar to the one on the leaf between the two metallic deposits. Any idea how that happened? P-236 is not advertised as a striking color or anything. Is it just a crappy batch?

Harry

Three Muses Glass · #2 2012-08-05, 1:45pm

That's actually pretty normal for dark turquoise. Even the light will do that. Those colors, copper green and a lot of other darker greens have copper in the mix. Try soaking it in toilet bowl cleaner like The Works (I get mine at the dollar store) for a little bit. If you haven't used that stuff before, wear gloves, it can bite. Get an old toothbrush and scrub it a little, see if it's coming off and you're good to go. It should come out fine.

And just FYI, that reduction is not always a bad thing.

28676bhe · #3 2012-08-05, 4:49pm

Almost looks like BE Egyptian Blue!

Harry · #4 2012-08-05, 6:50pm

Thanks three muses, I was trying to make the entire leaf metallic but it wouldn't take uniformly. I think it's very strange but I'll try the toilet bowl cleaner.

Three Muses Glass · #5 2012-08-05, 7:21pm

Oh wait....I just reread that post again. I didn't get that you wanted the reduction. lol Sorry. The toilet bowl cleaner will take it off.

Let me see if I have this straight. You wanted reduction but you want it uniform? Try this next time; reduce it until it's black with soot and then put it in the kiln. The soot will burn off in the kiln, so don't worry about it. It *may* make it uniform. I've had good results with other colors but don't think I've tried that with dk. turq. You'll run the risk of red streaks, much like heavily reduced copper green, but I like those. ymmv

RSimmons · #6 2012-08-06, 5:49am

The rings around the base of the gather are made of zinc coming to the surface. The toilet bowl cleaner should get rid of them.

Robert

truegem · #7 2012-08-08, 10:41am

I would keep it the way it is. I think it looks cool!

jaci · #8 2012-08-12, 11:48am

There are drink stirrers right. Im thinking that if you are stirring strongly acidic drinks over time that will dissolve this coating of zinc. Also I may be off on this, I know it's probably fairly safe, but food safety wise I wonder how it fairs?

Harry · #9 2012-08-13, 4:23pm

Yeah that's what I was worried about. I kind of like the metallic sheen but id be hesitant to actually stir a drink with it.

H

RSimmons · #10 2012-08-14, 8:37am

Metallic surfaces like this are never good for food/drink applications. It's also recommended that you not store acidic beverages (including things like port, sherry, etc.) in lead crystal containers for any length of time. For short term serving it's fine, but don't keep adult beverages in the decanter all the time.

Robert

truegem · #11 2012-08-16, 3:07am

Gosh, my parents used to keep some sort of alcohol in their decantur...for years! Oops!

RSimmons · #12 2012-08-16, 2:32pm

Quote:

Originally Posted by truegem

Gosh, my parents used to keep some sort of alcohol in their decantur...for years! Oops!

Lots of people do. If the decanter isn't fully air-tight the spirits will oxidize and lose their flavor. The acids will leach just a little bit of lead out of the crystal. Not enough to poison you in the short term, but I prefer to limit exposure to organic lead where I can.

Robert