UV-reactive, strontium-aluminate-infused 3D-printer bed glue that is stronger than Frank's "Instagoo" — plus an off-the-shelf UV coverage sensor and a Klipper pre-print gate that won't print on a bare bed.
A static SvelteKit SPA (built from the Tinyland site.scaffold), published to GitHub Pages at https://jesssullivan.github.io/tinyland-goo/. The page carries an interactive, weight-based batch scaler; this README is the source-of-record for hardware and citations.
just setup # npm install
just dev # dev server
just build # static build into ./build (BASE_PATH=/tinyland-goo)
just preview # local root previewjust is the single entrypoint — see just --list.
| Path | What |
|---|---|
src/routes/+page.svelte |
The article (recipe, BOM, gate, safety) |
src/lib/components/GlueScaler.svelte |
Weight-based batch scaler (by-weight, 0.01 g) |
klipper/coverage_gate.cfg |
PRINT_START + _COVERAGE_GATE macros |
klipper/coverage_gate.py |
Host script: AS7341 → Moonraker SAVE_VARIABLE |
By weight, for a 0.01 g scale. 1× ≈ 2 oz is the smallest worthwhile batch; 2× ≈ 4 oz is the recommended minimum (the scaler defaults to it).
| Ingredient | 4 oz (g) | Role |
|---|---|---|
| PVP-K90 | 8.00 | Film former — K90 (MW ~1.3M) beats Frank's K30 |
| PVA, 88% hydrolyzed | 2.40 | Toughness; pins a minimum water fraction |
| PEG-400 | 2.00 | Tackifier (highest-leverage bond knob) |
| 1% boric-acid stock | 1.70 | Trace PVA crosslink (~0.7% of PVA) |
| Coated SrAl₂O₄:Eu,Dy, 35–50 µm | 4.00 | UV coverage indicator (waterproof grade required) |
| Ethanol (≥95%) | 53.00 | Co-solvent; flashes off |
| Distilled water (free) | 41.72 | Dissolves PVA; carrier ≈ 55:45 EtOH:water |
Stronger than Frank's via three levers: PVP-K90 (cohesion), PEG-400 (tack), a trace boric-acid crosslink (cohesion without killing release). Solids ≈ 14.6%, PVP:PVA ≈ 77:23.
Watch out: bare strontium aluminate hydrolyzes in water and stops glowing — use a silica/fluoride-coated/encapsulated grade. Don't go anhydrous (PVA needs water).
A simpler derivation for an automated applicator on less mission-critical printers, from common stock only — no K90, no boric acid, no coated phosphor. Still beats Frank's via the PEG/PEO tack lever + slightly higher solids. Scales 1/2/4 oz.
| Ingredient | 1 oz (g) | Role |
|---|---|---|
| PVP-40 (K-30 class) | 2.80 | Backbone (same PVP grade as Frank's) |
| PVA lab powder | 1.10 | Toughness (PVP:PVA ≈ 72:28) |
| PEG/PEO powder (heavy MW) | 0.50 | Tackifier — the strength edge; potent & stringy, start low |
| Strontium aluminate (plain) | 1.00 | UV indicator — uncoated, mix small & use fresh |
| 91% isopropyl alcohol | 16.00 | Carrier (kept IPA-heavy to slow hydrolysis) |
| Distilled water | 6.95 | Dissolves the PVA (carrier ≈ 63:37 IPA:water) |
Adhesive solids ≈ 15.5%. Uncoated phosphor fades with water exposure → use fresh; heavy PEO strings → cut it if the applicator cobwebs.
SrAl₂O₄:Eu,Dy excites at ~365 nm and emits green ~520 nm. Flood the bed with 365 nm
UV; glued area glows green, bare bed stays dark. The AS7341 F4 (515 nm) / F5 (555 nm)
channels straddle the peak and its filters reject 365 nm, so a single-point read often
needs no separate filter. Baseline the bare bed once; coverage is the green rise above it.
Flammable alcohol carrier · phosphor dust (N95/P2 + eye protection when weighing) · boric acid (reproductive hazard if ingested) · 365 nm UV-A eye/skin hazard (enclose; pulse during read only).
- Frank's Instagoo — https://goo.by.frank.af/
- Homebrew PVP/PVA "Super Goop" (DrGhetto / Hackaday) — https://hackaday.com/2022/12/06/homebrew-3d-printer-goop-promises-better-bed-adhesion/
- Vision Miner Nano (SDS: IPA carrier, trade-secret polymer) — https://visionminer.com/products/nano-polymer-adhesive
- Luke's Laboratory bed adhesive — https://www.lukeslabonline.com/products/bed-adhesive
- PVP K30 vs K90 — https://ulipolymer.com/difference-between-pvp-k30-and-pvp-k90/
- PVP/PEG pressure-sensitive tack (~36 wt% optimum) — https://www.tandfonline.com/doi/abs/10.1080/00218460213491
- Boric-acid crosslinking of PVA — https://iopscience.iop.org/article/10.1088/2631-8695/ad4cb4
- Strontium aluminate (excitation/emission, water degradation) — https://en.wikipedia.org/wiki/Strontium_aluminate
- Encapsulation for water resistance — https://www.sciencedirect.com/science/article/abs/pii/S0254058407003719
- Coated/waterproof powder suppliers — https://www.technoglowproducts.com/strontium-aluminate/ · https://www.gloeffex.com/collections/super-phosphorescent-glow-powder
- SrAl₂O₄ SDS (no GHS hazard) — https://ltschem.com/msds/SrAl2O4.pdf
- AS7341 spectral sensor — https://www.adafruit.com/product/4698
- OSRAM LZ1-00UV0R-0000 (365 nm) — https://www.mouser.com/ProductDetail/LED-Engin/LZ1-00UV0R-0000
- MEAN WELL LDD-700H driver — https://www.mouser.com/ProductDetail/MEAN-WELL/LDD-700H-WDA
- Thorlabs FGL495 longpass / FBH520-10 bandpass — https://www.thorlabs.com/
- Klipper Command Templates (
action_raise_error,save_variables) — https://www.klipper3d.org/Command_Templates.html gcode_shell_command(KIAUH) — https://github.com/dw-0/kiauh/blob/master/docs/gcode_shell_command.md
CC0-1.0. Experimental — validate the recipe and hardware yourself.