This is not for the feint hearted ! But I am certain after going through this process that I documented and the videos I have recorded of Joe Robbertse making the Molds for the Hull, Decking, Hatches etc, you will immediatly see that it is not Rocket Science.
Most people never attempt to build their own designs because they believe its complicated. This is not the case. It just required that you follow the process set out below and do not attempt any short cuts.
My original idea was to modify
The upper decking and make the forward section rounder to shed water.
Add more bouyancy into the bow
Add side Chines running aft with tumblehome
To reduce some of the freeboard
Make a rear well to give easy access to the rudder shaft and linkage for easy transportation.
I knew the underwater lines worked - and that the fin and mast position was correct so those positions were documented or measured and will remain.
The Puma is a vice fee South African Design - and was more than capable in the right hands to be compeditive with the top boats. I really did enjoy sailing it, but saw some things I wanted to change.
These first ideas I discussed in detail with Craig Richards in Cape Town and he gave me some good advice - Thanks Craig.
After cutting the heck out of the Puma Hull I - the waterline below where the hull flared up reduced the width. This was in line of most current boats.
I then added the wooden gunnals and cross braces to ensure the hull retained its shape and added lazer cut perspex upper formers which I designed on my cad system. Slowly I could begin to visualise what was to follow!
High density polystyrene was then epoxied in between the formers and were slightly oversised. Once dry it was possible to sand the polystyrene down to the hard perspex formers which dictated the overall shape.
I glued 120 grit sandpaper onto long flat strips of pine wood with cold wood glue. Wood strips were about 50mm wide x 200mm long
The sanding strips can be seen in the photo on the right. Its ESSENTIAL to use these strips when sanding fore and aft to ensure you get and even fairing or transition from one hard former to the next.
Many sessions or sanding and filling were required to land up with this finish.
I used Pollyfiller first followed by spackle or a sanding filler which was very fine - When everything look FAIR and GOOD I applied a coat of EPOXY Fast Setting RESIN over the whole boat - deck and all.
This hard epoxy coating allowed me to work further on the hull without every little ding showing up on the polystyrene.
Use EPOXY resin NOT Polyester Resin as this will eat the polystyrene foam.
The epoxy layer can then be water papered down and if needed a second coat applied and waterpapered down using progressivly smoother grades to a fined finish is observed.
A light coat of 2 pack or aerosol paint will show up any imperfections.
And so the fill continues.
At this point the blemishes will be small, but never the less need to be filled. Use an automotive spot putty - it dries quickly and sands very well - Spray over again and keep going until you are satisfied the plug is smooth - shiny and any blemishes are really, really minot or small and can be lost in the mold or the molding of the final hull.
Remember you will still need to sand and spot putty the final molding of the hull as the decks and bow and transom ends are fitted and glued ( epoxied) in position and before final spraypainting of the hull to your choise of colour.