PAINTING YOUR HULL

Now a final sanding of the refilled areas, one last check over your hull and you are ready for the final finishing.   Usually you will be applying one of the polyurethane or epoxy finishes.   One last word on finishing - no matter how smooth and fair you think your hull is you may find it is not as perfect as you thought.    When you apply the final gloss, the truth will become apparent.   If you consider your finish absolutely perfect, then you will most likely be satisfied with the result.   If you accept less than a perfect finish now, you may be disappointed later.

   There is a wide selection of paints that are suitable for protecting the outside of a fibreglass hull - some for above the waterline, some for below.   The method of application of your finish coating, will depend upon which material you select.   If you believe your hull surface is sufficiently good to accept a high gloss finish, then you may be spraying your final coats.   If you are of the opinion that your hull surface will not look it’s best with a shiny smooth surface, then you may prefer to roll and brush on the finish coating.

   When you roll on your finishes using a short nap mohair roller, you will achieve a slightly orange peel effect.   This can be used to advantage by rolling the second last coat, lightly sanding the finish and then spraying the final coat.   This will take away the high gloss finish that may not be appropriate for your hull.   No matter what material you select as a finish coat, make sure you try samples before committing yourself to applying the material to the complete hull surface.    In some cases rolling followed immediately by brushing can give a passable finish to an imperfect hull.

   One last job before you turn you hull is to trim the sheerline after carefully marking it from the sheer batten.   You should have been doing this right through the laminating process, but if not, you will need to do it now.  You will need a tungsten tipped saw or a jigsaw fitted with a tungsten or diamond blade, to cut the fibreglass.   It is much easier to trim the sheer while the hull is upside down and close to the ground.

PREPARING FOR TURNING HULL UPRIGHT

After you trim the sheerline, install a 3” x ¾” [75mm x 20mm] timber batten around the sheer.   Scarf the batten to a length that will go right around one side of your hull.   The batten is first clamped in place and then secured to the hull using self tapping screws that are located every twelve inches [305mm] around the batten.   The screw should be long enough to go through the batten, the outer laminate and some way into the core,  not so long as to go into the mould.   After the mould is removed, install a similar batten inside the sheerline.   The reason for fitting the outer batten before the hull is turned over is to protect the edges of laminate and add some stiffness to the hull shell after the mould is removed.   Once the hull is turned and the mould is removed, you will find the hull is quite flexible, so the outer batten is part of the system that will keep your hull in shape until you can install the inner laminate, bulkheads and other hull stiffening.

TURNING THE HULL

There are several methods that have been used to successfully turn the hull and remove the mould former from the hull shell.   In some respects, the method you will choose will depend on the size of your boat.   Boats up to, say 25 feet [8 metres], can be handled without mechanical assistance.   A few bottles of cheer and a number of your friends will take care of the turning over operation.   For larger hulls a more serious approach is required.

   If you are building in a shed, it is a simple matter to turn you hull and mould over in one operation.   Use two chain blocks and endless slings that are placed around the hull about 25% in from the bow and stern.   The chain blocks are then used to raise the hull and mould off the floor and rotate the entire structure in the endless slings.   The hull can then lowered into a prepared cradle. Next attach the chain blocks to the mould structure and lift the mould out of the hull.   The hull is now moved out of the way and mould lowered and inverted ready for re-use, sale or demolishing.   Another method of turning hulls of any size is to use a crane fitted with a spreader bar and two endless slings.   Assuming the hull is in shed, it then has to be removed either by using pipe rollers placed under the strongback or dragged out on skids.

MOVING HULLS

You can move large, bulky and heavy hulls and decks by the use of the simplest of devices.   A few 2” diameter [50mm] pipe rollers 9’ [230mm] long can be used to roll your hull, if you set down planks for the rollers to run on and keep taking the rollers from the back and placing them at the front as the hull moves along the desired path – angle the rollers if you want to move the hull in that direction.   You should use 4” x 2” [100mm x 50mm] timber levers say 5’0” [1.5 M] long when you want to lift the hull and mould structure to slip pipe rollers under the strongback or bedlogs.  

   Another method we have used to turn large hulls is to build a framework around the hull.   A strong cradle built over the hull while it is upside down and braced through and under the sheer will make a good turning over cradle.   Use three sets of frames, one forward of the keel, one in the middle of the keel and one aft of the keel.   Diagonally bracing will be required.   See illustrations shown here for extra guidance.   Use coach bolts throughout the assembly of your turning over cradle.   When upright, the cradle should be capable of supporting the hull until you complete the project.   Once your hull is in the upright position, the crane can lift the mould from the hull and turn it upright ready for disposal.   If you reuse a mould you may be liable to pay the designer of your boat a royalty payment.  It is wise to check the legality of such a move.