Ludo,Grog...

[osnat]

Hello evryone,
I have the good book "Mould making for glass" of Angela Thwaites.
In this book Angela describe many kind of matirals
that use for making mould.

I want to ask you about few of them.
"Grog- ground per fired clay,Ludo- per fired refractoryould mix"

Do use those material?
Whether you buy these materials in stores as ready to use, or you "grounded" old mixes of mould such as quartz and plaster?
In what kind of shop can be found?

Thank
All the best
Osnat

[Peter Angel]

You buy grog from ceramic supply shops.

They sell it by the Kilo.

Pete

[Bert Weiss]

Grog is ground up insulating firebricks. It is very prone to stick to hot glass. Potters add it to their clay body to add strength and porosity. Bronze casters use it in their refractory mix. When casting glass, you need a splash coat next to the glass with no grog. The backup can have the grog.

Ludo is ground up refractory from a mold that has been fired.

Both can provide larger particles in a new refractory mix, that allow moisture to escape without cracking the mold. Beware that Ludo speeds up the setting of the wet mix.

[osnat]

Thanks to you all

Osnat

[Havi]

Osnat,
You can buy grog at Minerco, in Natanya.
You must make sure that you buy GRAINS of grog, not powder...

Good luck,

Havi,

[osnat]

Thank havi,

Last week I spoke with them and did not know what I'm talking about. I'll try again. Maybe they call it differently?
Thank
תודה רבה
Osnat

[Havi]

Osnat,
I do not know whom you talked to in Minerco.
I bought this staff from them several years ago. If I remember correctly, they did not have all the quantity I needed, and I had to come back again.
One of the more knowledgeable people in this store is YEHUDA, perhaps it is worth your while to call again, and ask to talk to him. Tell him that it is [was] black staff, that I bought from them several years ago. They had 2 sizes of grain, I took the bigger one. To my surprise I found out recently that he remembers me. I hope it will help.

If not try keramikon, perhaps they carry it too.
Remeber however, DO NOT BUY POWDER, ONLY GRAINS.

good luck

Havi