Next i used a heat-gun. This worked quite well! The wax melted pretty quickly. To speed up this process i first chopped the blocks into smaller pieces by knife. Trying to just cut of pieces didn’t work. Hitting it with brute force did.
I put the pieces in a pan, on a electric stove on level 3,5-4 (out of 5). Then i used the heat-gun to melt the top part. To avoid burning the bottom part i stirred frequently.
To optimise my technique i threw in a shallow layer of the larger pieces first. Once partly melted i stirred the wax, and put a thin layer of slightly smaller pieces on top. I repeated this process until the pan was full. Some of the pieces clumped together in the pan, i hold them up with my stirring spoon and used the heat-gun to melt. With this technique i needed around 20 minutes to melt enough wax for one brick.