10KY Hard Plumb Gold Paste Solder 10KY yellow paste solder supplied in a syringe of 1 DWT. This solder has a flow point of 1380 degrees Farenheit (749 degrees Celsius) and a melting point of 1335 degrees Farenheit (724 degrees Celsius). This Krohn syringe solder comes pre-mixed with flux, The syringe makes it ideal for fine jewellery repairs such as fine chains.