# Supplier RFQ — Slip-Cast Ceramic Ocarina (OCA-001 family)

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**Subject:** RFQ — slip-cast ceramic ocarina prototype materials and consumables

Hello,

I'm a mechanical R&D engineer prototyping a small family of slip-cast ceramic ocarinas (vessel flutes, ~3-4 in long, ~0.16 in / 4 mm wall) and need quotes for the following. The first build is an Alto C 12-hole prototype based on the parametric Helmholtz design table at [tonykoop/ocarina](https://github.com/tonykoop/ocarina).

## Items

| # | Item | Required spec | Approx. qty (per prototype run) |
|---|---|---|---|
| 1 | Cone 6 stoneware casting slip | Mature Cone 6 stoneware slip with **published shrinkage** (X/Y/Z), **water absorption %**, and **firing schedule**. White or light buff body preferred for tone consistency over dark iron-bearing slips. | 1-5 gal |
| 2 | #1 pottery plaster | USG #1 Pottery Plaster (or equivalent) suitable for absorbent slip-cast molds. Need **water:plaster ratio**, **set time**, **soluble salt content**. | 10 lb (single mold) — 50 lb (production mold set) |
| 3 | Mold release / mold soap | Plaster-compatible parting agent (Murphy's-type oil soap or commercial mold soap). | 1 bottle / 16 oz |
| 4 | Cone 6 exterior glaze | Food-safe (or durable non-food-safe) satin or matte glaze. Color: TBD per family — likely earth/buff/cream. Glaze must not bridge holes or windway. | 3-5 pints |
| 5 | Brushable wax resist | Standard ceramic wax resist for masking voicing window, finger holes, and chamber interior pre-glaze. | 1 small jar / 8 oz |
| 6 | Diamond needle file set (post-bisque tuning) | Assorted profiles (round, half-round, taper) ~3-6 mm; resin-bonded acceptable. | 1 set |
| 7 | Hole cutters / brass tube cutters | Round cutters from ~0.156 in (4 mm) to ~0.313 in (8 mm) diameter for greenware finger-hole cutting. | 1 set |
| 8 | Bisque + glaze firing service (if local) | Cone 06 bisque + Cone 6 glaze fire; small cubic-foot kiln load. | 2 fires per prototype |
| 9 | (Optional) Master printing/outsource | If you do high-resolution PLA or resin prints up to ~5 in long with **0.005 in dimensional accuracy**, please quote. We currently print in-house but want a backup. | 1-5 master pairs |

## What we need in your quote

- **Unit price** and any volume breaks
- **Minimum order quantity**
- **Current stock status** and **lead time**
- **Shipping estimate** to 94566 (Pleasanton, CA) — or local pickup option
- **Material safety data sheet (MSDS)** and **technical data sheet** for items 1, 2, 4, 5
- **Recommended substitutions** for thin-walled (~4 mm) musical instrument bodies
- For item 1: most recent **shrinkage test data** for your batch (we will re-measure on our side, but a baseline matters)

## Acceptance criteria

The prototypes are measured for X/Y/Z shrinkage, bore/cavity volume after firing, wall-thickness consistency, and acoustic tuning (chromatic tuner, ±25 cents target post-bisque). Slip with unknown or wildly variable shrinkage invalidates the master scale factor (currently `1/(1-0.12) = 1.136`), so reproducibility data is more valuable than headline price.

The repo is a private R&D portfolio repo; we do not need any IP-restricted documents. Public-domain MSDS and supplier spec sheets are sufficient.

Thank you,

Tony Koop
Mechanical R&D Engineer
tonykoop@gmail.com
github.com/tonykoop/ocarina (private; access on request)