It melts at a relatively low temperature and can be safely manipulated and shaped by hand. It can then be placed in the pitch bowl and heated slowly in a 250 or 300 degree oven. You can also heat it with steam in heavy stainless pot with about 4 inches of boiling water-boil about 1/2 hour. The easiest and safest way to soften pitch is with a heat gun. Some people use a torch, but, there is a danger of burning the pitch. Wrap the pitch in several layers of some heavy cloth or in a few plastic bags and moderately hit it a few times with a heavy hammer. Then, you can put the small pieces in your pitch bowl, only a few at a time. Now you should heat them with the heat gun until they melt and run together. Add more chunks as you go. Be sure to go slow taking your time. Over-heated pitch will become brittle once it's cooled again and can become useless. If overheated, pitch turns into carbon and loses its ability to support and adhere to the metal. You should remove the burnt area immediately to avoid further contamination of the pitch bowl. Once the pitch is melted let the pitch air-cool for several hours. We recommend you dip your fingers in water before attempting to handle hot pitch. If the surface of the pitch appears glossy, it is too hot to touch.
Warning: One 2 kilo loaf of pitch will not fill this pitch bowl full. It will be shy a 1/4 inch or so. You will need to either buy a second 2 kilo loaf or splash a little "quick concrete" in the bottom of your bowl first. If you do this, you will have enough and may even have some extra.