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Old 06-21-2013, 05:14 PM
  #15  
Caygeon Flyer
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Join Date: Oct 2005
Location: Bobcaygeon, ON, CANADA
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Default RE: Fiberglass Layup for a Large Model

I continue to appreciate all the input from folks. It is helping!!!

I have attached some photos of the parts that will be assembled to make the mould.
Today we decided to make the final assembly in about 4 pieces.

We will also be using a variety of layups and techniques for the various bits, although the final layups are not finalized yet.

The fin and aft part of the boom will be largely carbon fibre with some foam in the flat parts of the fin. We need to carry the horizontal tail plane loads down into the structure, and also avoid torsional issues with the boom.

The key structural piece is the bottom of the hull. This will be a glass and foam sandwich to provide stiffness to the bottom of water landings. We will likely use vacuum infusion for this part.

There will be some internal structure built onto the bottom part to carry batteries and electronics and also to transmit loads vertically from the bottom up to the wing spar and motor mount. (or vice versa).

The main part of the fuselage, incorporating the nose, cabin ,and underside of the wing mount, will be dropped over the structure and bonded to the bottom. This will be a multilayer glass layup, with foam as a stiffener in the large flattish areas. Also a big stiffener along the centre top, and vertically on the sides just under the motor area.

At this point we will be able to install the wing tube sleeve, and spars, and motor mount.
This will then be topped with a third glass piece which will primarily be the top of the wing surface and motor cowl. This again will be a glass sandwich with foam in the flattish areas.

I know some folks have suggested putting a coat of primer onto the moulds before the layup, but will not do this. We prefer the transparency of the parts which will let us visibly check bonds and bulkhead joints.

We are thinking of probably a first glass layer of 3 oz., as the large size and radii do not require the flexibility of 2 oz. The foam thickness will be from 2 mm to 6 mm depending on the needs of the individual parts. We have not decided on the final layer weight.


PS - More comments are welcome!

Caygeon FLyer
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