Sunday, September 09, 2007

Epoxy and Frimann picked up, laminating continues

I got back from Oslo last night, bringing more Ampreg 20 hand laminating epoxy (and some carbon, peel ply, release film, foam etc) and as a bonus, Frimann.

(To you guys on the F-boat forum complaining of low mileage and short wheel base: This vehicle has a wheelbase of 3320 mm (130,7 inches), goes 34 mpg (diesel) without a trailer and more than 25 mpg with Frimann (Trailer and boat approx 2000 kg or 4410 pounds, United States Customary units of mass) on Norwegian roads, steady as a train. Great family car, up to ten seats and room for all your gear. Get a German car!)

Today I continued the process of hand laminating the exterior of the floats. I recessed the reinforcement areas of the deck with the electrical planer, then laminated the deck. On the port float I used approx 3 kg of epoxy on this part so I started out with 2 kg. This turned out to be almost sufficient, I ended up using approx 2,3 kg. I do not know the reason for this, but possible explanations are:

1. This float is made up entirely of the new formula Divinycell. The port float was some old formula, some new formula. The improvement consists of smaller cells in the foam, hence a smoother surface (more like Core Cell) and one would expect less resin to be caught in the surface.
2. I used slow hardener in stead of standard. The slow hardener has a lower viscosity (which also applies to the mixed epoxy) and this may lead to easier wet out of the fabric (aramid is very hard to wet out and vacuum techniques are of great help when using these fibers) hence less epoxy applied until I was satisfied regarding the change of color as a sign of proper wet out.
3. My technique may have improved.
4. A combination of the factors above

I did not weigh the fabric, but rough calculations suggest it is 1,15 kg on the deck. This gives a fiber to resin ratio of 1:2 (actually a bit better, the peel ply is soaked with resin that will be removed) which is not very good but I did not get a very good ratio with this thin fabric and vacuum either. I think the amount of bubbles and a bit more calculations and speculations will decide what I am doing when it comes to the main hull. I really love the the feel and the finish and the certainty of quality that a vacuum treat provides.....

Here is today's status of the starboard float:

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