I have a big problem with the water-tightness of my boat shell. It shell MUST be very thin like no more then 0.40 mm after laminating, I made the first layer of spayed gelcoat GC50, then one layer of matt 30gr,  one fiber plane cloth 50gr, aramide 100gr and last fiber cloth 50gr. Then I put peelply, perforated sheet and absorber cloth. Next was to apply the vacuum for several hours until the epoxy resins cures. After de-moulding and pulling off the peelply I could achieved the required shell thickness. When I did the water-tight test the shell has had so many micro pores and leak badly. The next time I did the same with exception of peelply layer because it looked to me that pull off this layer opened the micro pores. In that manner I increased the shall thickness for more then 50% !!!! Water-tightness is OK but the boat shell is to thick and to heavy and it is not competitive. 
Please HELP me with suggestions how to make water-tight shell at minimum thickness !!! What lamination layers and fibre you can suggest?
Thank you in advance and best regards,
Miroslav