Fusion Frit F621/19

Alternate Names: F 621/19

Oxide	Analysis	Formula
CaO	12.45%	0.66
Na2O	7.14%	0.34
Al2O3	9.90%	0.29
B2O3	14.90%	0.64
SiO2	55.61%	2.74
Oxide Weight		296.66
Formula Weight		296.66

Notes

Fusion recommends this as a better substitute for Ferro Frit 3124 than F-19 (Mar 2021). Yet this frit has a chemistry less similar to Ferro 3124 than F19.
This is the same as F-19 but with 2% less CaO. They do not release the chemistry of this so we just reduced the CaO and retotalled to 100.

Related Information

Ferro Frit 3124 vs Fusion F621/19 at cone 04

Fusion Frit F621/19 is recommended as a substitute candidate for Ferro Frit 3124. However, as shown on this melt fluidity test of the two pure frit powders, it appears to have a lower surface tension and flow better. However the character of the flow is opposite to what is expected of a lower surface tension in the melt. There should either be a lower population of micro-bubbles or they should be smaller - but the opposite is the case. There should be fewer breaking at the surface and they should be healing better - but that is not the case. Frits are supposed to be free of carbon or hydrates - or are they? If the frit is sourcing gases because of raw materials not fully decomposing during smelting - how is that even possible? Do you know why this is happening, can you tell me please? Fusion Ceramics does not supply the chemistry of Frit F621/19 and it is not shown on their website in 2021, but I have no reason to believe it contains fluorine.

Ferro Frit 3124 vs Fusion F-19 at cone 04

On paper, Fusion Frit F-19 has a very similar chemistry to 3124. However, as can be seen here, it is flowing a little more and appears to have a lower surface tension. The entrained bubbles are bigger so the glass is more transparent. This brings up some of the same puzzling questions as did our tests on their Fusion Frit F621/19.

Links

Materials	Ferro Frit 3124 A commonly available calcium borosilicate frit.
Materials	Fusion Frit F-19 A commonly available calcium borosilicate frit having a similar chemistry to Ferro Frit 3124.
Typecodes	Frit A frit is the powdered form a man-made glass. Frits are premelted, then ground to a glass. They have tightly controlled chemistries, they are available for glazes of all types.

By Tony Hansen
Follow me on

Got a Question?

Buy me a coffee and we can talk