Why isn't my gold melting?
Your gold likely isn't melting because the heat you are applying is not sufficient in quantity (BTUs) or is being lost too quickly, preventing the metal from reaching or maintaining its melting point.
Melting gold requires significant heat energy delivered efficiently to the metal itself. Several factors can prevent this from happening:
Insufficient Heat Input (BTU)
One of the most common reasons your gold isn't melting, even if the flame looks hot, is related to utilizing the heat you are putting in. As one reference points out, "Most torches may get hot enough, but may fail to put in enough btu to actually heat the metal sufficently." While the torch flame might reach temperatures above gold's melting point (1064 °C or 1948 °F), it may not transfer enough heat energy (measured in BTUs - British Thermal Units) into the mass of the gold quickly enough to raise its temperature uniformly to the melting point. A small detail torch might be hot, but lacks the volume of heat needed for a larger piece of gold.
Excessive Heat Loss
Another critical factor is heat escaping from your setup before it can melt the gold. Gold is a good conductor of heat, meaning it can lose heat to its surroundings rapidly.
- Uninsulated Melting Surface: The surface holding the gold can draw heat away. Keeping your melting dish on an insulated surface is crucial. The reference specifically advises, "Keep your melting dish on an insulated surface." This prevents heat from being absorbed by a workbench or other non-insulated surface, directing more energy into the gold.
- Drafts or Airflow: Air moving over the crucible can also wick heat away.
- Crucible Type: Some crucible materials conduct heat away from the gold more readily than others.
Improper Torch Technique
How you apply the heat matters.
- Flame Type: Different parts of a torch flame have different temperatures and heat transfer properties. The hottest and most effective part of the flame is typically the tip of the inner cone.
- Distance and Angle: Holding the torch too far away or at the wrong angle reduces the efficiency of heat transfer. The flame should be focused directly onto the gold in the crucible.
Equipment Issues
The equipment you are using might not be suitable for the task.
- Inadequate Torch: Using a torch that is too small or not designed for melting metals (like a small propane torch meant for soldering) will not provide enough BTU output. You might need a larger torch, perhaps an oxy-propane or oxy-acetylene setup, depending on the amount of gold.
- Damaged Equipment: A malfunctioning torch or a crucible with cracks can lead to inefficient heating or heat loss.
- Incorrect Crucible: Using the wrong type or size of crucible for the amount of gold can hinder melting.
Gold Purity and Impurities
While pure gold melts at a specific temperature, alloys (mixtures with other metals) have different melting points, often lower. However, certain impurities or contaminants on the gold or in the crucible can also affect melting, sometimes requiring higher temperatures or reacting poorly to the heat.
To successfully melt gold, ensure you have a torch with sufficient BTU output, minimize heat loss by using an insulated melting surface and appropriate crucible, and apply the heat efficiently.
