I have however reached a bit of a problem when trying to make a mould for an engine component from a k20 Honda engine. My problem is the lines in the original part (see the attached pictures) there are three lines which go across and i don't wont them on my finished part, i have tried filling them with the filleting wax but you can still tell they were there on the mould. Also i just put some filleting wax in the holes which secure the part to the car, is this the done thing? i obviously will be drilling them out on the final part when i pull it from the mould so not much of an issue.