Thread: ring tests
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Old 10-25-2019, 02:26 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
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Silica is actually a very powerful way to move expansion and if at a rather low 55%, it would be the material I would consider.

Is this still based in Dave's formula. I haven't looked at its percentages but these seem pretty strange

Try to recall that with the old bob held study, he established you could add up to 5% calcium mono phosphate and still be compatible with the basic clear. The problem was the calcium creating Apatite stones so going to Strontium and dumping the calcium out of the base was necessary. Since the strontium had a not dissimilar excpansion factor, this was not a tough substitution. It feels like you've strayed from the earlier materials.
So at this point, I'm assuming you are using Sodium tri phosphate for the phosphate source (Is it?). That should make for a fairly easy transfer from the soda ash as well.

I just never had this trouble with the Bross formula although I spent little time with it. Also, my clear was non commercial but matched SP87 on expansion and viscosity, which was the point.

Here's what Jordan did with this stuff:
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
While I don't know your intent, you've wandered far from home. The silica alone is remarkable.
Where are we going and why am I in this basket?
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