First Double Bias Layup on Second Aka

Here are a few shots of my evolving technique for laying heavy 12 ounce double bias carbon on an aka over wood and pultrusion.

Cut the cloth.  I was using about 4 foot sections.  On the first aka I used longer ones, but they were difficult to handle.  They also did not want to conform to the curve of the beam well.  They would trail off over the side make for uneven overlap points.

Prime the raw plywood on the beam.

Start wetting out the cloth.  This stuff soaks up crazy amounts of epoxy.  You need to use plenty and be very patient about getting it thoroughly wet and even.

I spread a wave of epoxy back and forth making sure to get all edges.  I have been using a very liberal amount.  Excess epoxy rolls off the cloth, but can be scavenged back to the middle.  After one side is wet I flip the cloth and start over.  Usually the other side of the cloth is only about 10% wet when turned.

Once both sides are quite wet, I fold the plastic over the cloth to create an envelope.

The envelope is squeegeed with heavy pressure.

The squeegee creates a wave of air and epoxy.  It is very difficult to see how wet the cloth is prior to this.  I pull the epoxy in about six directions (+-90 and +-45).  I flip the envelope and do it again on the other side. At this point, I'm pretty sure that it is wet all the way through.  I carefully peel back the envelope and the peel off the cloth.  This needs to be done with even pull as one does when removing tape.  Uneven peeling will distort the cloth and fray the edges.

The cloth is transported gingerly to the aka.  I have been overlapping about a half inch.  The wet cloth is firmly milked  across the beam with the gloved hand  I Want it tight and smooth.  

Later, the rise in the overlap will need to be carefully ground back smooth. I only want disturb the second layer and feather it in.

Peel ply is stretched across the surface.  It gets wetter than this picture as it is worked to get the air out smoothly.  The peel ply is a lot less compliant on the curves than the carbon and usually needs a few darts along the sides.

Task time: 4 hours

Total project time: 362 hours 

Aka Wrap

Here are a couple pictures of the first layer of bidirectional carbon wrapped around an aka.  I start laying up more pultrusion tomorrow. Two more layers on each side and then it gets wrapped again.

Task time: 24 hours

Total project time: 382 hours

The Slows

I have been busy with some other projects and have only spent about 20 hours on the boat the last couple of weeks.  Tasks include more layers of uni carbon protrulsion and fairing corners of the pultrusion layers into the beam corners. The stacks of pultrusion create gaps that have to be faired before layers of bi-directional cloth can be laid over the top and bottom of the aka beams. You get glue squeeze out under the clamps and it makes for inconsistent edges.  I'm doing some test layups to see if I can find a more uniform way of doing these.  Pictures later...

I have calculated there are about 20 more carbon layups for the beams.  About 16 of these require hand clamping every six inches.

There is more information on the Cheers posters at PT Watercraft.

Task time: 20 hours

Total project time: 232 hours

Slow Progress

Life got in the way and between a trip to get materials and other responsibilities not much got done for four days.

I did do some prep for the next steps on the akas.  Surface sanding and rounding over the edges.  I have also been pondering the best methods to apply layers of strips of pultrusion and 400 gsm carbon double bias.  These have to be clamped and/or vacuum bagged over the eighteen foot span.

A layer of five strips of pultrusion will look something like this only longer.

Current state of the beams.

Also got a stack of douglas fir ripped for the mainsheet beam laminations.  These were a bit wet and will need to dry with the heaters and a fan for a while.  Think I need a moisture gauge.

Task time: 8 hours

Total project time: 194 hours