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Melt fluidity comparison - 1650F

Fired at 350F/hr to 1650F and held for 15 minutes. FZ16 has turned crystal clear and spread out across the runway (has low surface tension). Frit 3110 has so much surface tension that the flow can be lifted off the tester. Since 1600F Gerstley Borate has gone from unmelted to passing all the rest!

Wednesday 1st January 2020

The myth of aging clay

Do you really need to age clay when you make your own? No. In ancient Japan they did not have power blenders and propeller mixers, we do. To illustrate: I just sieved out the +80 mesh and +200 mesh particles from this raw clay (from one of our stockpiles) and then propeller-mixed it as a slurry. ... more

Wednesday 18th December 2019

Aged commercial clay really needs to be wedged before use

This is a cut through an eight-month-old slug of pugged clay. The cut was done near the surface. The patchy coloration is a by-product of the aging process. If a slice of this was fired in a kiln, an even and homogeneous white surface would emerge, with no hint of what you see here. A few moments of wedging will mix the matrix and ready it for wheel throwing or hand forming.

Wednesday 18th December 2019

Hand-tooling a mug model vs. 3D-printing a mold to cast it

I am creating molds for a 2019 casting-jiggering project to reproduce heavy stoneware mugs manufactured here 50 years ago. I have a profile drawing I want to match (upper left). The solid plaster model on the left was my first attempt at manual tooling. The metal template was time-consuming to ... more

Friday 13th December 2019

Cone 10R mugs made with new casting-jiggering process

Very exciting! The easiest batch of mugs I have ever made, no wheel throwing or trimming. These are made from two casting recipes I am working on to match the fired appearance and glaze compatibility of Plainsman H550 and H440 (buff and iron red burning bodies). This is how many you have to make to learn some of the finer points of the process.

Friday 13th December 2019

3D-Printed shell to cast working plaster jigger molds

The grey outer shell mold on the left was printed in two parts and glued together (at the shoulder). It's vertical split enables me to open it a little. The center model of the outside contour of the mug (on a two-step base) was made by casting the plaster inside another two-piece 3D-printed form I ... more

Friday 6th December 2019

The incredible utility of 3D printing master handle molds

These molds are 3D-printed from PLA filament. They are part of my 2019 year-long casting-jiggering project. A quick soaping, 164g water, 236g plaster and a fifteen minute set produced this plaster mold. It takes time to learn how to soap the masters properly to get optimum quality, but these molds ... more

Thursday 5th December 2019

Fusion 360, my choice for 3D modelling

Intimidation by the complexity of this type of software is the biggest obstacle you will face to learning 3D design (for 3D-printing). That being said, the new mission of AutoDesk, the leader in CAD software for 30 years, is to make it easy and universal! Fusion 360 has a lot of advantages. It is a ... more

Thursday 5th December 2019

Polish the plaster surface, not the 3D-printed shell-mold

This plaster model was just removed from the 3D-printed shell behind. It dropped out easily (after tapping it at-an-angle on the corners), this worked well despite the resolution lines on the surface. While I could have spent time sanding and smoothing the inside of the shell-mold, it is actually ... more

Thursday 5th December 2019

A 3D-printed spout greatly increases the utility of this casting mold

It was glued down using the casting slip itself (it stuck in seconds). About ten minutes after draining a fettling knife was run around the inside, then it detached easily. The overhung lip produced imparts structural strength, for drying and firing, to the thin walled piece. This spout has ... more

Sunday 1st December 2019

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