# Spacing, Stacking, and Placing Posts

Unit: The Final Bake: Glaze Firing
Topic: Loading a Glaze Kiln
URL: https://claybook.studio/learn/spacing-stacking-and-placing-posts/

# Building an Efficient Glaze Load

Once you understand clearance and kiln wash, the goal becomes loading the kiln efficiently: fitting as many pots as possible while respecting all the spacing rules.

## Kiln Posts and Shelf Heights

Kiln posts are refractory columns that support the shelves above your pots. They come in various heights. Choose post heights that give you:

*   At least 1-2 cm of clearance above the tallest pot on that shelf.
*   Enough room to reach in and position pieces safely.

Use three posts per shelf arranged in a triangle for stable, level support. Uneven posts cause shelves to rock and pots to tip.

## Strategic Placement

*   **Place the tallest pots on the lowest shelf** where you have the most room to adjust post height.
*   **Short pots go together** on the same shelf to avoid wasting vertical space with tall posts.
*   **Work from the bottom up**: set the bottom shelf first, load it, add posts, set the next shelf, and continue.
*   **Leave the top shelf for low, open forms** like plates and platters.

## Checking Before You Close

Before closing the kiln lid or door, do a final visual check:

*   No pots are touching each other.
*   No glaze is visible on the bottom of any foot ring.
*   All shelves are level and stable.
*   Cone pack is visible through the peep hole.
*   The lid can close without touching any pot.

A two-minute check now prevents a load of destroyed pots later.

## Final Door-Close Checklist
Right before firing:
* No pot or lid touches an element, wall, or each other
* All shelves feel stable with a slight push
* Cones visible in at least one peep per shelf zone

Make this checklist automatic and glaze firings get much less stressful.

## Dig Deeper

Efficient kiln loading is a skill that develops over time, and it matters whether you are firing [earthenware](https://en.wikipedia.org/wiki/Earthenware), [stoneware](https://en.wikipedia.org/wiki/Stoneware), or [porcelain](https://en.wikipedia.org/wiki/Porcelain). Each clay type has different glaze flow characteristics at its target cone, which directly affects how much clearance you need between pieces.

## Common Mistakes and Quick Fixes

*   **Using unstable shelf support**: Standardize to three-post triangle support per shelf.
*   **Wasting vertical space**: Group similar heights and choose post sizes intentionally.
*   **No final stability test**: Slightly tap shelves and verify no rocking before close.
*   **Forgetting cone visibility**: Confirm cone packs can be read through peep holes.

## Practice Exercise

Photograph one finished kiln load before closing. After unloading, compare the photo with outcomes and note where spacing was too tight or too conservative. This feedback loop sharpens loading judgment quickly.

## Check your understanding

### Question 1: How many posts should support each kiln shelf, and why?

- [ ] A. Two posts, one at each end
- [ ] B. Four posts, one at each corner
- [x] C. Three posts in a triangle for stable, level support
- [ ] D. As many posts as fit on the shelf

Tip: Three posts arranged in a triangle provide stable, level support. Four posts can cause rocking if the shelf or floor is uneven.

### Question 2: Where should the tallest pots be placed in a glaze kiln load?

- [ ] A. On the top shelf, closest to the lid
- [x] B. On the lowest shelf where post height can be adjusted most easily
- [ ] C. In the centre of the kiln for even heat exposure
- [ ] D. It does not matter: any shelf works for any height

Tip: Tallest pots go on the lowest shelf, where post height is easiest to adjust and there is the most room to accommodate them.