Sunday, June 01, 2008

Both float hulls now glassed

It is a bit of a milestone to have both float hulls glassed. I can now present them upright in the garage and work on the float decks.

Here are pictures of the two float hulls out of the garage. It is interesting to see the various colours of the light fillers that I have been using.

The hulls look a little rough around the keel where the last lamination finished. The hulls are as is, no cleanup, but with all the peel ply removed.

Just to review the materials used.
Fiberglass cloth: 2 layers of the following cloth from BGF Industries

Style: 7781
Finish: 497A
Weave Pattern: 8 HS
Yarn Description:
Warp: ECDE 75 1/0
Fill: ECDE 75 1/0
Count: Ends X Picks (in) 57 X 54
Weight: 8.71 oz / yd²
Breaking Strength: (lb / in)
Warp: 242 lb / in
Fill: 231 lb / in
Thickness: 0.0089 in
The strategy with this cloth was two-fold. First, the fine 8HS weave is very drapeable with little crimp, resulting in better strength than a plain weave cloth.

Secondly, applying 2 layers at the same time hopefully optimizes the glass to resin ratio. The purpose of the epoxy resin is to communicate stresses from one fiber to the next. This cloth with ~55 strands of fiberglass per inch has very little space when laid up, to be filled with resin.

Applying the peel ply and plastic has resulted in a very good quality lamination. The cloth is very firmly attached to the foam and the weight seems to be optimized. The 'high contact angle' air bubbles have not been observed anywhere. They seem to be a thing of the past and the quality of the laminations have really improved from the 'early learning escapades' on the float interior to the outside hull.

Epoxy Resin: PTM&W MVS-420 resin MVS-468 hardener.
This resin gives the working time I need 2-2.5 hours but then cures at a rate I like. If I work through the afternoon on a part I can expect to be able to rip off the peel ply early the next day. The Aeropoxy resin would take days.

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