Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[G-Flex]

Kind of an obvious suggestion, and probably something that's already on the table, but I'd like to see more materials used in glazing.

• Apparently, lead (or lead compounds, at least) are very important to tin-glazing, usually constituting more of the glaze than the tin does, with the tin oxide acting largely as an opacifying agent. It would be nice to see lead get a use in realistic decorations like this, at any rate, since as of now it's a pretty useless metal.
• Salt-glazing. Rock salt needs uses anyway, and this is a decent way to glaze pottery (in a probably lower-value form than other glazes) when other materials aren't available.
• There are mineral-based underglazes, like the common blue cobalt oxide based stuff you see on white porcelain, which are very much within the tech constraints and could be used for painting specific decorations on glazed pottery. Of course, being underglazes, you apply them prior to glazing (which is when they set), creating a minor interface/usability problem, since they can't just be separate decorations you add later, at least not realistically.

There are probably other examples too that fall specifically under the category of glazing and not general paints and such, but hey. it's a start.

[Nikov]

A quick bit of google-fu reveals cinnabar glaze, cobalt glaze, ...

A Motherlode! Praise the miners!

[G-Flex]

Interesting link. The only thing is, with a lot of these pigments and such, it's hard to tell what the primary constituent of the glaze is supposed to be (for instance, what is iron oxide used with, and is it used as a sort of underglazing or in the coating?) and what the exact production method is, and how period-appropriate it is.

[Nikov]

Well, the easiest way is to reduce it into practical materials known by dwarves, and assume anything not requiring complex chemistry is known. After all, 1400's Europe isn't a good way to judge the understanding of minerals possessed by a civilization that lives in underground mining complexes. From what I can tell, cobalt, cinnabar, malachite, hematite, nickle, rutile, limonite, and cassiterite are all processed and used as colorants. That gives us blue, bright red, black, dark red, green, white, brown, and ... actually I can't figure out what color cassiterite makes.

I'm thinking... millstone or quern, sand bag + pigment ore = glaze bag [10 pigment glaze powders]. That seems sufficiently straightforward and practical. Non-sand sources of the glaze base could be explored, however.

[G-Flex]

From what I can tell, cobalt, cinnabar, malachite, hematite, nickle, rutile, limonite, and cassiterite are all processed and used as colorants. That gives us blue, bright red, black, dark red, green, white, brown, and ... actually I can't figure out what color cassiterite makes.

Problem is, usually when people say something like "cobalt pigment", they aren't being specific, and are actually referring to some compound of cobalt. In this case, we know it's tech-appropriate, because we know blue cobalt pigments were in use a long, long time ago.

Nickel is a little different, for instance. Which compounds of nickel do dwarves have access to? In fact, pure metallic nickel itself is kind of odd for dwarves to have (same with zinc).

Cassiterite is just a source of tin oxide for tin-glazing, which basically looks white. In reality, you apparently also use lead compounds for tin-glazing, and probably other forms of glazing, with the SnO2 acting as an opacifying agent.

I'm thinking... millstone or quern, sand bag + pigment ore = glaze bag [10 pigment glaze powders]. That seems sufficiently straightforward and practical. Non-sand sources of the glaze base could be explored, however.

I don't know if sand is strictly necessary, but it probably depends on the glaze; in a lot of glazing, apparently, the silica in the clay itself is enough. I'm not sure, though.

Breaking down a rock of a certain mineral into a bag of powders isn't a bad idea, though. At the least, there would need to be some way to use a single stone of mineral for more than one job.

[Nikov]

NICKEL OXIDE - (m.p. 742o F/400o C) Green: NiO Green Nickel Oxide (typically <3%) is used in glazes (most commonly porcelain enamels) to produce blues, greys, browns, and yellows, depending on the molecular equivalence of the Alkalies, Alkaline earths chosen. It can also be used to soften the effect of Cobalt and Copper colorants.
Black: Ni2O3 in a glaze Black Nickel Oxide will reduce to Green Nickel Oxide at 600o C and produces similar results as NiO. Greater amounts may need to be added to a glaze to achieve the same effects.

Evermind that 'green' bit. Most of these metals are used in oxide form, which is the naturally occurring ore for many of them. It would definately take further research to determine what is possible, but we've at least found some data to work with.

[NW_Kohaku]

Well, there's the more recent suggestion that went on about a week or so ago, and the older one where Gazz was talking about all this stuff. 

For questions like "could dwarves really make the specific compounds used in modern glazing?" the answer is probably "no," but that doesn't mean they can't use them at all.  "Cobalt Blue" was used since the dawn of civilization, but it was never really the same type of cobalt that they used, and the cobalt blues would change based upon where they mined up the cobalt. 

Regardless, however, cobalt is blue, even if there are impurities messing with what precise color blue it might be.  Likewise, iron makes rust red, which can be turned various colors of red or brown or orange with different impurities, but iron generally just makes rust red. 

That said, there are more problems with stoneware and porcelain, especially porcelain.  Porcelain and stoneware are man-made (dwarf-made) stones.  You have to put them into semi-molten state in the kiln to fire them.  And porcelain is magma-proof in the sense that magma is around 400 degrees Farenhiet (200 Celcius) too cold to fire porcelain.  Even stoneware may need to be at least 100 degrees hotter without flux. (Flux in this case being something like microcline or orthoclase.) This was why I made the original proposal way back when in 40d to have a power-using machine with fans to generate a high-temperature kiln that could actually fire porcelain by supplying constant oxygen supplies and large quantities of fuel for temperatures magma just doesn't provide. 

I also was talking in that other thread about how silly it is to have an entire wall's worth of metal ore go into the glaze of a single pot, whose clay is considered so miniscule a portion of material that it can never deplete a tile of floor.  So basically, we have some sort of bizzare non-Euclidian geometry going on where several tons of material can be used in a minutely thin layering on top of a functionally non-existant amount of mass.

Quietust went and made an example reaction, as well...

[G-Flex]

Yeah, I probably should have searched a little better first. Whoops.