Q.
Who do I make a fiberglass cowl for my plane?

A.
This brings up many Questions on my Part.. :-) I will break up the Answer in several parts.
    Making your your templet for the mold of a cowl. There are several materials you could use to do the jode. 
  • Molding Putty
  • Play doe
      1. I would go for the Molding putty of Play doe ( A smooth finish will be left )
      2. I would cover the front of the fuselage with with ether glad rap or if it is a finished surface with solar film ( or your choice of covering ). If you wish to leave the Motor on the fuse, cover that as well ( only with Glad rap )
      3. Apply the putty to the front of the fuse. remember that there must be no part of the plane showing where the putty is places. 
      4. Mold the Putty to the shape that you desire
      5. Smoothen the surface as thow it is the finished product
    • Remember that any imperfections that you leave on this Putty Cowl will be there in the finished fiberglass cowl.
  • Polystyrene
  • blocks of Balsa wood
    • I this type of Molding you have to be good with wood.
      1. Find a Big enough peace of Polystyrene and Glue the Polystyrene to the Fire wall. same goes with the Balsa wood but that is hard to find so glue scraps to gather to shape a cowl out of. ( Use you imagination a bit ) 
      2. Sand the surface to the shape that you desire
      3. Smoothen the surface as thow it is the finished product.
      4. With Polystyrene , cover it with a thin layer of epoxy and then sand that so it to is with out fault. ( All we are doing that for is to get rid of the imperfections inherit with Polystyrene )
      5. As for the Balsa wood I would go for dope.
    • Remember that any imperfections that you leave on this Putty Cowl will be there in the finished fiberglass cowl.

     

Now that is dune you must have a Backing plate or Flange that comes out about an inch directly behind the serface you just molded into place. This will be used for the Mold that we are just about to make. This will become the rim of the mold. It gives it strength and also a great place to have splash over of the resen.

    Now we have a Fuselage with a fake cowl on the front of it. NOW is the time we start to make a Mold for the real fiberglass cowl. This also has steps you must follow.

    1. You must get a Releasing agent. this comes in two types a wax and a type of paint on film. Thay both act as a separating film between the Hardened surface and the Resin you are about to apply. ( A type of condom if you wish to see it that way :-) No serface should not be with out this film because if there is no film the resin will stick to it like :-) Glue. To get the releasing agent go to your fiberglass supplier and ask there. As for the wax, do not leave big lumps of wax on the surface.... it is a thin film....
    2. it is best to have aposing resens when designing a mold. You have to make a desition. Do you want the cowl to be made of Apoxy or Poliester fiberglass ? if you want an Apoxy Cowl you make the mold of Poliester and Visa-Versa.
    3. Make  the first bach of resen to cover the howl serface ( Dont be bashful use alot ) and wait till it just gets that stage befor it is taky to tuch( If you wish use a heat gun to spead it up a bit ). Now mix the reson ( Same type ) to layer on with the fiberglass. 
    4. Leav to set .... There you are you have a Mold.... Just take it of and remove the fack Cowl from within it.

    Now we have a mold what about the Cowl that we want to make ? it is egsaktly the same...

    1. Coat the mold with the releasing agent just like ubouve. 
    2. Cut the fiberglass to a pattern so it will lay in the mold nisely.
    3. If you made the mold out of Poliesta reson the cowl will be of Apoxy. and just like ubouve.
    4. Make  the first bach of resen to cover the howl serface ( Dont be bashful use alot ) and wait till it just gets that stage befor it is taky to tuch( If you wish use a heat gun to spead it up a bit ). Now mix the reson ( Same type ) to layer on with the fiberglass. 
    5. and now put the fibeeglass and reson around the sides. 
    6. Once it is dry and has hardend simply take the cowl out of the mold. it might be hard at first but it will seperate.