CraftWEB Hot Glass Talk  

Go Back   CraftWEB Hot Glass Talk > Color work from rods and batch glasses

Reply
 
Thread Tools Display Modes
  #26  
Old 02-14-2018, 06:26 PM
Dave Bross Dave Bross is offline
Registered User
 
Join Date: Apr 2002
Location: Archer FL(near Gainesville)
Posts: 2,949
Dave Bross is on a distinguished road
Jordan,

Strontium will help. Lithium will help a lot.

If you have Volf read up on strontium. Similar effects as lead without the toxicity.

Be very sure you have enough alumina with strontium (Volf) as in sum of 1st column in periodic table divided by eight (Labino).
__________________
Art is not a thing...it's a way.

Last edited by Dave Bross; 02-14-2018 at 06:31 PM.
Reply With Quote
  #27  
Old 02-20-2018, 11:49 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
I added back half the borax from Dave's original recipe and a little bit of cryolite. I also doubled the potassium nitrate after looking at my other recipes. Small charges every 1.25 hours with a good stir in between each charge. It's looking really nice so far. We shall see.
__________________
WWUD? Think for yourself.
Reply With Quote
  #28  
Old 02-21-2018, 06:07 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
Wow, it's gorgeous. Does exactly what I wanted. Pops right out of the furnace and has that beautiful fiery glow. It is also possible I screwed up my first melt of the 5% somehow, which has always been a thought in my head.

Added half of Dave's borax after reading boron was helpful, added .75% cryolite for same, doubled pot nitrate, pulverized the lithium with the STPP, small charges with stirring to maintain furnace temp as high as possible throughout the melt. There was only a very small patch of scum on the surface, similar in size to a patch of frogs eggs one sometimes gets. Raked off nice and easy. Gorgeous glass underneath. I suspect the patch would not have formed if I had stuck around for an extra hour after I put the last charge in to stir. Just need to adjust expansion now.

Thanks everyone!
__________________
WWUD? Think for yourself.
Reply With Quote
  #29  
Old 02-22-2018, 08:02 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
Those patches take forever to go away by themselves. If it's bubbles, I don't rake, I squirt them with a windex type bottle on straight spray.
Given Durk's suggestion regarding the formation of borates as an unpleasant side effect of the borax plus moisture, it makes me wonder if it might be better to use boric acid or anhydrous borax. The boric acid would bring expansion down, something borax really doesn't do. I tend to put the nitrates in a coffee grinder since all of that stuff is prilled now and the things are too big.

I was charging a cobalt silver opal and a copper ruby yesterday and had time to consider Volf on the subject of strontium and it doesn't really quite say it can substitute in part or whole on the calcium but it is clear to me that the less calcium the better if you don't like Apatite chunks. It was wise of you to crush the STP in the lithium. It's a favorite trick.

I haven't tried a copper ruby since I left New Mexico. Doing that with a moly is a futile exercise but with this little gas furnace I'm running now, my old 7,000 feet in the foothills formula was rather intense and a thread the size of a human hair struck very well on the outside of a clear gather, to the point that I cut the copper content in half and still have a red strike going on a punty whereas the goal was to have it strike in the annealer. Making it as a phosphate might be remarkable, sort of like those old Mother of Pearl colors Zimmermann used to make.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #30  
Old 02-24-2018, 12:23 PM
Shawn Watt Shawn Watt is offline
Registered User
 
Join Date: May 2010
Location: Branson, MO
Posts: 97
Shawn Watt is on a distinguished road
Pete I would be really interested in hearing more about the copper ruby phosphate. for some reason i was under the impression that because the ruby needs to be reduced so much that it wouldn't work in a phosphate base that has the oxygen. Could you walk me through that?
Reply With Quote
  #31  
Old 02-24-2018, 01:24 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
well, as I said, making it might be remarkable, so when I get it, I'll remark in better detail. .

In general, your glass is chock full of oxygen no matter what you do. All those carbonates. If you break your glass down in , moles, you can really see it. So you need something there to "reduce" ( make smaller) the 02 everywhere. Black tin works well. So would metallic copper but would be a PIA,

The formula for Tri sodium Phosphate is Na3PO4. Sodium tri phosphate is Na5P3O10 but each one would have oxygen glommed on to it. The old guano was really about 55% calcium and around 42% Phosphorous and oxygen. The theoretical formula for it is Ca5(OH)(PO4)3, but it varies. Real bone ash is hard to find and you really will have a lot of trouble with the calcium in it making apatite crystals which are really gross.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #32  
Old 02-24-2018, 04:50 PM
Shawn Watt Shawn Watt is offline
Registered User
 
Join Date: May 2010
Location: Branson, MO
Posts: 97
Shawn Watt is on a distinguished road
When I took chucks class he worked on cad sel colors in a phosphate base. If i remember right he was using mono calcium phosphate to reduce the O2. They turned out really nice i thought. I hadn't thought about the copper ruby until you said it. Looking forward to future remarks
Reply With Quote
  #33  
Old 02-25-2018, 08:14 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
Quote:
Originally Posted by Shawn Watt View Post
When I took chucks class he worked on cad sel colors in a phosphate base. If i remember right he was using mono calcium phosphate to reduce the O2. They turned out really nice i thought. I hadn't thought about the copper ruby until you said it. Looking forward to future remarks
*****
do you have a source on the mono calcium phosphate?
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #34  
Old 12-19-2018, 11:58 PM
Lynn Read Lynn Read is offline
Registered User
 
Join Date: Aug 2008
Location: Portland, OR
Posts: 12
Lynn Read is on a distinguished road
Quote:
Originally Posted by Jordan Kube View Post
So I melted this 5% opal the other day:

In pounds
Sand 7.3125
Soda Ash 2.38875
Potassium Carbonate 0
Calcium Carbonate 0.4125
Strontium Carbonate 0.675
Zinc Oxide 0.225
Alumina Hydrate 0.3375
Lithium Carbonate 0.075
Antimony 0.03975
Potassium Nitrate 0.075
Sodium Tripolyphosp. 0.93

Total 12.471

Oxides %
SiO2 66.86
Na2O 16.4
K2O 0.327
LiO 0.278
CaO 2.13
MgO 0.006
SrO 4.35
ZnO 2.06
Al2O3 2.229
P2O5 4.95
Sb2O5 0.365

Charged a few scoops at 2300 every two hours. Held at 2300 for 10 hrs and then down to 2150. It came out pretty scuzzy on top like you guys talk about some phosphates coming out. It was also pretty streaky in coloration and cordy looking. It blew out ok and the stuff I made into bar struck out beautifully after being picked up again, as always. As a note, I ground the STPP in a bullet blender in an effort to avoid some chunkies I was getting in the 2.5% melts. It also came out 4 points high after my educated guess on adjustment. Based on that and my percentages I'm thinking at least adding some silica is in order.

Any thoughts on cleaning this one up?
---
Hey Guys, Jordan and Pete,

I have been reading this thread and wanted to ask if you think this Sagahara glass is a Na5P3O10 opal (STPP)? It has so many amazing hues of blue and golds but the density is so slight I would imagine it must be only .5 %- 1% max phosphate. Based on the images that Jordan posted at 5% I would be far to dense.

I want to run some test melts but trying to gain some feedback first. I will be press molding the glass with a wall thickness of 1.2" - 3/4" thick so I need to limit the saturation. I will be cycling the glass through a cold work process and a second firing for my final fire polish. I am sure the duration of heat cycles will effect the opacity with this glass. I am hopeful that I can get a nice pale smokey white.

Any advise would be helpful in regard to % of STPP or strategies to get the shift if warm and cool tones. Maybe it is just the shape of the glass refracting color.
Attached Images
File Type: jpg Sagahara opalescent vase.jpg (24.5 KB, 38 views)
Reply With Quote
  #35  
Old 12-20-2018, 08:51 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
That density is probably correct. In the STP melts I've done, it is periodically really streaky stuff, almost like a comb was run thru it but if reannealed, it really took on opacity. Press molding will no doubt do something unexpected but the re strikes matter a lot. Streaking seems to be a repeat concern with it. Kenny wrote me about that last week and I really didn't have great insight. Keep the calcium as low as humanly possible.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #36  
Old 12-20-2018, 10:54 AM
Dan Vanantwerp Dan Vanantwerp is offline
Registered User
 
Join Date: Apr 2017
Location: Bozeman, MT
Posts: 255
Dan Vanantwerp is on a distinguished road
Looks like silver fuming to me. Almost wonder if that's some boro tubing.

So far my attempts have not yielded as much "fire opal" as just opal. The red only came out when overlaying a chalcedony color. Very interesting look.
__________________
My furnace setting: 2112
Reply With Quote
  #37  
Old 12-20-2018, 01:33 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
I would be very surprised to find that was not a generic phosphate opal actually.

I have a large piece of Mark Peiser's in our bedroom and its a monolithic casting six inches thick by about 30 inches of a Phosphate glass, which is all Mark works with. During the day it changes from translucent white to yellow to blue and then to red.

The thing that was driven into me over the years was how important the modifiers and stabilizers are in a base glass. They totally determine the color with few exceptions. Calcium is not your friend when making color. Neither is sodium.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #38  
Old 12-20-2018, 07:08 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
You will probably need to let it cool and then heat it back up after pressing to get any color out of it. You are really going to be able to take advantage of the beauty of this glass with those thicknesses. I would start at 2%
__________________
WWUD? Think for yourself.
Reply With Quote
  #39  
Old 12-20-2018, 08:56 PM
Lynn Read Lynn Read is offline
Registered User
 
Join Date: Aug 2008
Location: Portland, OR
Posts: 12
Lynn Read is on a distinguished road
Thanks for the feedback. It will take me a couple weeks before I can start the tests but if I get any positive results I'll share some photos. Cheers to taking notes.
Reply With Quote
  #40  
Old 12-21-2018, 01:14 AM
David Patchen's Avatar
David Patchen David Patchen is offline
Registered User
 
Join Date: Sep 2005
Location: San Francisco, CA
Posts: 1,863
David Patchen is on a distinguished road
You might hit up George Bucquet--he makes some beautiful opaline glass.

http://www.georgebucquet.com/
Reply With Quote
  #41  
Old 12-21-2018, 12:14 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
Always worth remembering where the 5% phosphate content came from. That was out of the 1968 NCECA conference ( pre GAS) where Robert Held established that you could add up to 5% bone ash 21 to your basic clear formula and it would still be compatible with the existing formula. It was never a density guideline.

Bone Ash 21 was a curious true bone ash. Greasy, irregular, maybe bat guano that Standard ceramic supply marketed. They had one box car full of it and that was the end of it. It was profoundly difficult to melt cleanly, taking fine screening and temperatures over 2400F. The formation of Apatite stones was the problem which occur with the introduction of any calcium source. So, having calcium in your basic formula just makes things worse. Strontium as a substitute stabilizer fell into use but the number of people melting this stuff was tiny. Mark went into it immediately and has yet to depart and continues to get best results with Calcium monophosphate which is incredible difficult to obtain. Sodium tri phosphate works most of the time with some inexplicable deviations and so does Tri Sodium Phosphate which puts a lot more sodium in the melt.

If one accepts the notion that sodium and calcium are not your friends in this type melt due to the stones AND the color, then going to sourcing such as potassium nitrate and strontium carb would draw you in. Dumping as much calcium as possible is a step in the right direction. If I had any major criticism of the formula Jordan offered up, it's the sodium content. I haven't melted a phosphate opal in years but I would certainly think hard about switching alkaline fluxes. Bathe the STP in the lithium if you use a little and that would help as well.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #42  
Old 12-21-2018, 08:00 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
Mono Potassium Phosphate would perhaps be a good choice then Pete?

KH2PO4
__________________
WWUD? Think for yourself.
Reply With Quote
  #43  
Old 12-22-2018, 08:37 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
I have no idea. You need a little calcium. Emphasis on little. I don't actually know the structure for such a material. (PAUSE)
OK, here's calcium monophosphate: Ca(H2PO4)2 divalent
Here's potassium phosphate: K(H2PO4) divalent

phosphorous : valence 5
Phosphate combo valence 3

worth noting in the pentavalent form (Ca5) it appears to grow apatite, not your friend unless you love bone snot.

So armed with that info, I think it might be worthwhile to try it although it sounds like a fairly obscure compound to be found in your average chem supply warehouse. I think that really breaking it down would take a trip into mole chemistry. Count your atoms.

None of this clarifies much for me. Melt some.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #44  
Old 12-22-2018, 02:56 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
A little obscure, sure. Food and fetilizer chemicals. Not our usual source for supplies. I was able to find the Pot phosphate in 50# bags for $2.38/# delivered here https://www.greenwaybiotech.com/coll...ant=1557348161

I could not say the same for the Cal monophosphate. It is a pretty common food additive so someone has it for cheap.

You know me Pete, I'm always happy to try something rather than speculate. Thanks for the breakdown.
__________________
WWUD? Think for yourself.
Reply With Quote
  #45  
Old 12-22-2018, 04:36 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
I was unsuccessful on the Cal monophosphate which surprised me so I went with the STP and have 100 lbs which will take me to the end of the line. The STP does inexplicably streak, even to the point of leaving what look like fingerprints at times. On a reanneal, it's dense and has great color. The trouble I see with the fertilizer grade is the tramp stuff.
It turns out your bones are largely apatite in the pentavalent state. A state you want to stay away from. Right now, I'm melting copper blues and they are so stunningly beautiful and so stupid easy.

Report back on the pot phosphate. It's a very interesting idea. That's not a terrible price although getting it back east might cost.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #46  
Old 12-22-2018, 06:15 PM
Jordan Kube Jordan Kube is offline
?
 
Join Date: Aug 2003
Location: Seattle, WA
Posts: 1,647
Jordan Kube is on a distinguished road
Free shipping.

I'm not currently melting batch but I do have a place in mind that might accommodate me. If I wasn't so taken with machining at the moment I'd probably have a little test furnace going by now.

Yes to the copper blue. Really the most beautiful blue out there, isn't it?
__________________
WWUD? Think for yourself.
Reply With Quote
  #47  
Old 12-23-2018, 09:10 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
I think it's eye popping. Make it with potassium and barium!

As to the pot phosphate: It's likely it will come to you "Prilled". I don't care for prilling since it's hard to mix in. I have to run all that stuff through a grinder and I would imagine that Phosphates will really need fine grinding. Bathe the junk in the lithium.

Clearly you need a glass melter in the CNC shop.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #48  
Old 01-03-2019, 03:38 PM
Lynn Read Lynn Read is offline
Registered User
 
Join Date: Aug 2008
Location: Portland, OR
Posts: 12
Lynn Read is on a distinguished road
So far my tests are not producing the results I want.

My batch is Spruce Pine W/er 87. I have tried STPP at 2% and not visible white showing. It is melting clean at 2350 but I am only melting small 50 lbs tests.

My next test will be is to increase the STPP to 4% and see if it shows. I may then test with Nono calcium Phosphate. Some people say it is much easier to melt with S. P.

Am I way of the mark to achieving a low density opal white using Spruce Pine?
Reply With Quote
  #49  
Old 01-03-2019, 06:56 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 20,603
Pete VanderLaan is on a distinguished road
5% would give results but it does matter where the bone ash came from. I've had some good results from STP and some from commercial Calcium Phosphates which did nothing. I assume a type Not Nono but Monocalcium phosphate but the synthetically derived stuff did nothing in my work ever.

It is not one of those glasses that gives you instant gratification, far from it. Calcium makes life Ugly. SP has Calcium.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #50  
Old 01-03-2019, 08:13 PM
Dave Bross Dave Bross is offline
Registered User
 
Join Date: Apr 2002
Location: Archer FL(near Gainesville)
Posts: 2,949
Dave Bross is on a distinguished road
Way too much calcium in SP.

This is one glass you have to batch from scratch due to the calcium being required to be a very low percentage.

It's worth the trouble to mix it up as batch. Instructions and how to for small amounts are further back in this post.
__________________
Art is not a thing...it's a way.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 06:48 PM.


All published comments within these message boards are the opinions of its contributor and does not represent
the opinion(s) of the owner(s) of this website. Please see the Terms of Use file for more details.

Books to Help Artists Avoid Online Scams: Top 10 Email Scams | Social Media Scams

Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
CraftWEB.com. Opportunity Network. 2008. All Rights Reserved.