This method was developed over several models to produce a fiberglass fuselage cheaply by anyone with a few basic skills and can result in a good model very quickly
 Whether you start with a commercial plan or one of your own it does not matter the basic requirement is the same. A profile shape of the fuselage from above and from the side and some section shapes along the length  of the fuselage about 4-6” apart.

  Material required :

• A piece of RHS steel about 1” square and about two feet longer than the fuselage plus some means of supporting it at each end. I have a stand on wheels at each end with a piece of pipe into which the RHS goes with a hole drill at right angles through the RHS and pipe at one end so a rod, screwdriver etc can be put through the holes and lock the RHS in any position.
  

• 3/8 MDF board ( known in NZ as Custom wood)
  

• 1/8 MDF board
  

• Glue
  

• Preferably a small nail gun firing 1” X 1/16 nails
  

• Wallboard filling compound  ( this is the product used to “stop” or fill the joints etc on the interior wall boards of houses. It comes in different “set” times I use 45 minute it allows you to do a reasonable amount before it sets off . This is a “Plaster of Paris” type material mixed with water.)
  

• Fibreglass materials of your choice ( Polyester or Epoxy and their parting agents etc)

  To start cut 2 complete profiles side and top views of the fuselage from 3/8 MDF. Cut these  1/8 smaller than the plan around the outer edge. Remove a 1” strip from the centerline of each piece  of the 4 pieces. Now join the like pieces together by screwing (not gluing) with the screws no closer than 2” from the outside edge. You should now have a top, bottom and a left and right . Glue with epoxy all 4 pieces around the RHS and you have the basis of the fuselage. Cut the section shapes once again 1/8 smaller around the outer edge and 3/8 smaller on each side of the right angle to allow for the thickness of the previously made profiles. Glue these sections onto the profiles in the appropriate place and it should look something like photo  # 1

           

 Cut into strips the 1/8 MDF about 3/8” wide and start planking the fuselage frames gluing and nailing as you go. This does not have to be pretty you will find the strips will just about find their own position but try to keep it “Fair” working from the center inwards and leaving about 1/8 gap between the strips. It should be looking like photo # 2
 Before totally covering with the strips I stuff the interior with newspapers just to stop the filler all running right through the gaps you should be ending up with something like photo # 3