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-   -   Neodymium effecting expansion? (http://talk.craftweb.com/showthread.php?t=12439)

Josh Bernbaum 10-06-2019 11:40 AM

Neodymium effecting expansion?
 
So I was able to get a good price on some chemicals that Mr. Dudley Gibberson was interested in getting rid of recently. It was a pleasure getting to see his shop in the woods in NH and what he'd been doing there figuring out glass melting stuff since before almost anyone else in our studio glass movement. One of the things he parted ways with was a bunch of Neodymium. I haven't done any melts with this colorant yet, but I'd like to add some in with a phosphate mix I'll do tomorrow. After reading some of Weyl on this, and wanting a somewhat stronger effect from the Neo, I thought I'd go with a 4% addition. Weyl suspected that the "Alexandrite" glass produced by Moser in Czech. was a 4%, and upon looking at images online of their antique (and maybe still current?) products, I think that's a nice coloration. So question then is, since I don't see it listed on the two spreadhseets I have, will this have any significant effect on expansion, and if so, up or down? Just curious to know if I should plan on compensating in my mix. Thanks

Pete VanderLaan 10-06-2019 02:13 PM

I've gone as high as 2% with no ill effects but I suspect 4% is a stretch. I also think that the color may not really get that much more dense and Neodymium isn't cheap. A general rule is that it will lower the expansion, not raise it. That's the case with most oxides.

I had told Dudley to call you and it sounds like he did. I have no further interest in stocking my batch room. Did you get any of the Potassium hydroxide? That's useful. I got a big tub of arsenic from him some years back and a bunch of red lead. I still have it having not done any lead melts in the last year. I will likely make an enamel white before too long.

Josh Bernbaum 10-06-2019 02:50 PM

Yes, thanks Pete for letting him know that, he did call me after you two had spoke. Didn't grab the K hydroxide. Actually never heard of that form of potassium but did see it on Dudley's list and I shied away from that and any other potassium-containing things because I figured how long they've been sitting around and that they tend to absorb moisture and get clumpy. He did give me about 40 lbs. of Pb monosilicate he had left in a bucket. And about 10 lbs. of gold sands he'd made years ago by partially dissolving a South African Krugerand which I got to see the remains of. And then he charged me a reasonable price for that Nd and some Erbium and some Nickel.

I did just read in Volf one sentence in which he indicated that the Lanthanides (sp?) didn't mess with expansion much, but do lower viscosity, and that they might be similar in expansion to Zinc or Tin? I've heard of 2% on the Neo before, but wanted to push it up a bit to see if I could get a richer effect, even though I realize it's not a powerful colorant. And I got a good deal on the stuff so I figured why not, but it would indeed be a bit wasteful if it didn't fit my clear..

Pete VanderLaan 10-06-2019 03:45 PM

well, I thought that I had gotten all the lead or you wouldn't have any.

Are you planning to case the neo in clear? If so, do a small melt using the basic 2% and add another 2% to that, melt it and try it. If you don't do that, mix a full load and try it and if it doesn't work out, mix that with some straight clear.

I've often felt that the Neo was also a fining agent that was really effective. That interior electron ring does some unpredictable stuff. That color maintains a clarity that I love.

The potassium hydroxide was well stored and seemed clean. It's really handy if you are making silver or copper bases and don't want the oxygen from the carbonate.

Pete VanderLaan 10-06-2019 06:00 PM

Having had an afternoon with baseball on the couch something really did occur to me which is at 4% you may begin to run into a saturation issue. 4% added means something else is diminished. I don't know what your clear base would be but that implies that it's being reduced from either the modifiers, the stabilizers or the network former. You still need a balanced glass. Lead would help you "Pack" the neo in there but it needs to be balanced overall. I have to do that with the dense black or it just is too much.

Josh Bernbaum 10-06-2019 06:36 PM

It's a big-ish mix with the modified Brossphate base that I've been doing lately.
Just under 53 lbs. total, which includes the 2 lbs. of Neo. If I can't get all the colorant into solution, like you see if you did your dense black without Pb, then should I be able to tell that immediately with a test gather right after the first 5 lbs or so goes flat?

Pete VanderLaan 10-06-2019 07:16 PM

Take a base mix at 2%. Isolate 5-10 lbs of it and add the additional 2%.

melt that . Fine it. Test it the next day against the clear. Do a ring test at the minimum. I realize I'm asking you to put three days in this but breaking it up is way worse.

This really takes patience to get it right. Most shops refuse to be patient. Respecting process pays off.

Bradley Howes 10-08-2019 09:11 AM

I've done some 4% melts in the past when I was using a ceramics kiln and using spectrum cullet as my base. It was far from even an okay setup but I did run into issues of having some kind of precipitate or haze at the bottom of my crucibles. For compatibility, you'll be straddling the line between compatible and not though most cases it'll be not.
Again, this setup was pretty bad but I figured I'd give my two cents.

Pete VanderLaan 10-08-2019 09:59 AM

Quote:

Originally Posted by Pete VanderLaan (Post 145464)
Take a base mix at 2%. Isolate 5-10 lbs of it and add the additional 2%.

****
I should have been clearer here. Since you are adding it to 10lbs, getting it up to 4% would be a different calculation based on weight.

Josh Bernbaum 10-08-2019 07:32 PM

The 4% (just under actually) seems to look okay in the samples I pulled last night, but I'll be using and making a test cup with it tomorrow so I'll post an update after that.

Pete VanderLaan 10-09-2019 09:00 AM

That sort of thing gets interesting when one cools down the glass. It will frequently crystalize below 2000F but then become glassy again when heated. I've seen such stuff also cystalize when rolled from hot onto a marver.

The best question is however "How was the color? Was it worth the extra 2%?

Josh Bernbaum 10-09-2019 06:43 PM

So I had already mixed the 4% when your recommendation came in to start with the 2% and try that first. Which was a good recommendation indeed, I just skipped that step for now. So I melted about 50 lbs. of the 4% on Monday and gathered it up today. Made lots of cane, a test cup, and some small blown things. The color is even, I didn't see anything to indicate it didn't go into solution properly. And it does indeed look different under fluorescent vs. incandescent/LED light. In fact, it looked the BEST when I was reheating it in the glory. I wish it could look like that all the time. In the light from the flame in there, it looked like a light gold purple, just a gorgeous color.. But in my shop lights it was less dramatic of a color, but still what I'm familiar with seeing on others' Nd melts. It was definitely a light kind of coloration, even at 4%, so I'm not sure I'd want to drop it 50% unless I had to for fit (which remains to be seen). Or if that extra 2% indeed doesn't add anything extra for coloration density as you were questioning Pete, since the stuff is expensive, despite the good price I got from Dudley. I may try another melt with lower concentration, we'll see, I've just got a long-ish list of future melts, only one pot in there, and only a few more weeks that I'll have the gas furnace going. But we'll see.

Pete VanderLaan 10-09-2019 08:45 PM

I think you'll get the same intensity of color with half ( or less) of the Nd. Mine are always a strong purple ( or blue) but I don't know if the high potassium content in my glass is affecting that. I could send you a chunk of what mine looks like.

You may have gotten a great price on the neo, but you're still young. You will wind up buying more eventually. Next time it may not be so cheap. At this point I get to wonder about whether I've already had the worst injury I'll ever get doing this junk. I wonder whether the cadmium supply is really a lifetime one ( I think it is). I still hoard lead.

Shawn Watt 10-10-2019 08:39 AM

I've done quite a few of the rare earth melts and 3% is usually my sweet spot. I mix in heavier potassium base as well. I adjust a little with Soda but I generally don't case it in clear either. Neo seems to make the glass work shorter. Its really designing around the thickness of the glass is where the color shines IMO.

Terry Crider 10-10-2019 11:20 AM

A lot of antique Neo had "thick and thin" in each piece - then under different lighting especially on a white table cloth it really "played tricks" on your eyes.

Josh Bernbaum 10-10-2019 04:33 PM

2 Attachment(s)
It did fit my clear pretty well, was able to saw a clean ring today but expansion of this Neo melt might be a tad high because I felt just an ooch of overlap on the score in the ring. But it did saw cleanly.. Here are two pics I'm attaching of a cup in different light, all color in this (no clear case). This is just under the 4% Neo in my modified version of the Brossphate. It's about a 2.7% P2O5 content. One of my mods was adding potassium, so about 30/70 potash/soda ash in there. And a bit extra from the KNO3 I used this time. I've got some more in the pot and gonna try some thicker things tomorrow.

Pete VanderLaan 10-10-2019 05:14 PM

I've never felt that casing in clear benefitted the overal color of the work and always added a mismatch issue potential to the mix. The phosphate seems to naturally fluoresce without rare earths. While I don't know what Dudley sold you the stuff for, I last bought it at what I thought a fair price ten years back and that was at $8.00 a lb. That was well below average pricing. Usually it was far worse than that. My favorite memories are buying Selenium for $ 4.00 lb in fifty pound tins in El Paso where the copper smelters worked. That's sure gone but Eveline bringing it to me from Shanghai for nothing seems better.

Larry Cazes 10-10-2019 07:10 PM

Quote:

Originally Posted by Josh Bernbaum (Post 145510)
It did fit my clear pretty well, was able to saw a clean ring today but expansion of this Neo melt might be a tad high because I felt just an ooch of overlap on the score in the ring. But it did saw cleanly.. Here are two pics I'm attaching of a cup in different light, all color in this (no clear case). This is just under the 4% Neo in my modified version of the Brossphate. It's about a 2.7% P2O5 content. One of my mods was adding potassium, so about 30/70 potash/soda ash in there. And a bit extra from the KNO3 I used this time. I've got some more in the pot and gonna try some thicker things tomorrow.


Thats Gorgeous!

Kenny Pieper 10-16-2019 01:32 PM

[quote= I still hoard lead.[/QUOTE]

I know a fellow who has more than he will ever use. I think he would be open to selling some.... if someone was interested

Pete VanderLaan 10-16-2019 04:14 PM

Quote:

Originally Posted by Kenny Pieper (Post 145575)
I know a fellow who has more than he will ever use. I think he would be open to selling some.... if someone was interested

****
In what form Kenny? Is it the 30 mesh stuff?

Kenny Pieper 10-17-2019 12:15 PM

Yea it's pretty big and bysilica

Pete VanderLaan 10-17-2019 02:13 PM

the fenton stuff? How has it worked for you?

Kenny Pieper 10-17-2019 08:02 PM

Well I have used it for duro, gold ruby, and opal. Seems fine.


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