what's happening here? stringing?

[curious aardvark]

to make a mould watertight - you need to print it solid. Now with most slicers 100% infill is NOT solid. usually you need to tick a box in the slicer that adds a solid diaphragm and set it to make one every layer. That will then make a totally solid, utterly watertight print that should work fine for a resin mould. Obviously you still need to get the printing temp and speed right as well. But you can certainly make watertight moulds.

[steveh2112]

thanks, where is the solid option in cura? not seeing it