Ultra Beginner questions : mould building.

Is building a female mold directly is a viable option, or do you need to build a plug first, and build the mold on that plug ?

There were photos of an express 40 mould built directly, but the company seems to no longer exists, and photos have gone.

Mould for infusion, in two halves or with removable flanges for deck , not expected to be used for more than 2-3 units. Rather easy sailboat hull form in 28-33 ft range. Boat to be gelcoated, not painted.

Nb a bunch of other issues are to be solved , such as deck manufacturing/joining and may change hull mould options (flanges ...)

 

It might be possible to create a female mould,but I doubt that people would be fighting to be allowed to fair the surface.I would also think you would be headed for leakage problems if you tried infusion,but maybe a coating of an impermeable material would help.I would have fewer concerns about building a female mould for the deck and coachroof,except for the challenge of making it actually fit the hull.

 

Seems some does it : http://www.3dwmoulds.com/cont_E_178.phtml

At least for the hull. For the deck, it is unclear. Looks a plug buit on the hull or on the mold.

How the fairing is done is unknown. It look they have a very small station spacing.

 

Here's some lovely stuff from Jon Sayer........ http://www.sayerdesign.com/

 

since this is the beginner mould building... talking about a tunnel hull?

 

If build the mold with CNC it doesn't matter.