CHECKING THE MOULD

A ½”  x  ¾” x 6’-0” [12mm x 20mm x 2m] long timber fairing batten laid diagonally across the mould battens will show up the high and low spots on your mould.   If there are any localized bumps or lumps, such as where you have joined the battens, you should fair these areas using an angle sander fitted with a heavy grit disc.   Something in the region of 16 grit should be ideal for the job.   Now is the time for you to go carefully over the entire hull and fair off any irregularities with the sander.   As in all your work from now on, let your eye be the judge.   View the mould from every angle and when you are satisfied that it is as fair as you can possibly make it, it is time to take the next step in your building programme.

FINISHING THE MOULD

By this stage you should have decided whether you are going to use a cored method such as PVC foam or balsa to provide the sandwich structure or the cheaper urethane foam, which will later be removed, and add stringers to the interior of your hull.   The next step is to cover the entire mould structure with builders’ plastic.   This plastic is quite thin but strong.   Check at your local hardware store where you should get a good choice of materials.   The plastic comes in rolls and is best installed by taping it into position with plastic tape and stapling where necessary – cover staple holes with plastic tape.     Once you have the mould covered in plastic the next job will be to install the core material.

OPEN FORM VERSUS SOLID FORM MOULDS