Two separate parts
Right 81.8 g, left 68.4 g by the model. Both are straight prisms from an open mold, and each stands on the table by itself.
A concept for a couple, a wedding or an anniversary. Nothing has physically been cast or lit yet: everything below is calculation.
The lock holds. Fire may join them.
Two halves of a wax heart seat into each other with a dovetail. Light both, and the melt may weld the seam, and then the halves stay together for good. Here those words are only a condition: for now it is a hypothesis, and only a test burn can check it.
Light it in the model- 92 × 77 × 36 mm
- 150 g of wax by the model
- 2 wicks, 53 mm apart
At first, justtwo castings
The tail enters from above
Neck 14 mm, head 24 mm, length 10 mm. The slot is 0.4 mm larger per side, so the half lowers into it vertically.
It holds only sideways
The lock does not hold upward: lift by both parts. Modeled play is 0.77 mm across the tail, and 1.17 mm after 20 cycles. That is an estimate, not a measurement.
Touch a half of the heart
This is a model, not a measurement. The parameters are assumed, and pool growth comes from a candle makers' rule for a different wax: about Ø25 mm per hour.
16.4 mm to the slot
Dashed: candle makers' rule. Pool edge: Stefan model. Thin lines: 35 and 45 °C.
Burn timeh
- Rule, pool
- —
- Model, left
- —
- Model, right
- —
Light the left half, the right half or both.
Each lighting restarts the calculation from zero.
Past one hour: the label no longer allows this, so from here it is only calculation.
The model is still computing this time on your device.
Hours to the seam.Seconds along it.
Once melt reaches the gap, capillary action takes over: the pressure is small, but so is the path. The lock's gap is 0.4 mm per side. Pick a gap and a length, then release the wax: the animation runs in real time.
Gap
Path along the seam
0.00 s
- Capillary pressure
- 140 Pa
- Speed
- 23.3 mm/s
- Time for this path
- 0.86 s
Viscosity and surface tension here are only an order of magnitude. Only freezing will stop the wax, and the calculation cannot say how far it gets first. The line on the diagram is thicker than the real gap.
“For good”is a condition, not a property
If the seam ends up in the melt, the halves should weld and no longer separate. Only if experiment 2 confirms that will we say for good. Without a test burn it cannot be promised.
There is an awkward point. The label limits burning to one hour. By the candle makers' rule the pool reaches the slot at about 1.3 h, in the model not within 2 h. So within an hour it probably will not touch the slot. Whether the halves weld under the label's conditions is still unknown.
Experiment 2: the seam in fire
Two discs from any pillar candle, cut with a hot wire, no tooling. A seam 10 and 20 mm from the top, three burns of one hour each on a non-combustible stand.
- Does the seam leak?not tested
- Does it weld?not tested
- Does the top part still come off?not tested
What we do not know
- No source gives the strength of a welded seam.
- Two wicks 53 mm apart: no source gives a minimum distance, only candle makers' warnings that merged pools and flames are dangerous.
- From the right wick to the outer wall is 19.1 mm: by the rule the pool gets there at 1.5 h. Only burning will show how a thin wall behaves.
The label, a draft
Decorative item for adults, not a toy. Contains small fragile parts. Keep out of reach of children and animals. Before lighting, place on a non-combustible surface, light only the top part, do not leave unattended, burn for no more than 1 hour. Carry disassembled, do not lift by the top part.
Translated from the Ukrainian draft for the whole line of multi-part candles. It is here because the one-hour limit bears directly on the welding hypothesis.
The wording alone does not settle how the item is classified. Before any sale, a short consultation with a lawyer or a laboratory is needed.
The same numbers as a table
If the scene did not start, everything is here. The rule's diameter is computed directly, the model's from melted area. After 2 hours the model's mean radius is 15.4 mm, less than the 16.4 mm to the slot: with these assumed parameters the model does not touch the joint, though the rule puts contact at 1.3 h. Only burning can settle the difference.
| Time | Rule, Ø mm | Model, left, Ø mm | Rule, to slot, mm |
|---|---|---|---|
| 0:00 | 0.0 | 0.0 | 16.4 |
| 0:15 | 6.3 | 12.2 | 13.3 |
| 0:30 | 12.5 | 18.4 | 10.1 |
| 0:45 | 18.8 | 22.3 | 7.0 |
| 1:00 | 25.0 | 25.0 | 3.9 |
| 1:15 | 31.3 | 27.1 | 0.8 |
| 1:30 | 37.5 | 28.6 | reached |
| 1:45 | 43.8 | 29.9 | reached |
| 2:00 | 50.0 | 30.8 | reached |
Model parameters
- Report: density 900 kg/m³
- Report: heat of fusion 180 kJ/kg
- Report: conductivity 0.24 W/m·K
- Report: melting 58 °C, room 23 °C
- Report: gap 0.4 mm
- Candle makers' rule: layer 13 mm, top of the 6–13 mm pool depth range
- Assumed: heat capacity 2500 J/kg·K
- Assumed: mixing in the pool, conductivity × 4
- Assumed: surface losses 10 W/m²·K
- Assumed: heating spot 4 mm
- Fitted to the rule: power into wax 1.22 W per wick
- Grid 0.5 mm, step 0.12 s, a flat problem seen from above
What is not here
- No measurements of any kind: not force, not burning, not shrinkage.
- The model is flat: it ignores depth, wax consumption, flame movement and spilling over the edge.
- This page sells nothing and collects no data: no price, no order, no contacts.