Saturday, June 18, 2011

More mast

I had the day off, that's always good for building progress.  Removed the bag this morning, and the bleeder was evenly saturated as a sign of adequate wet out, and also that the epoxy hadn't cured before I got the bag on.  It takes a lot of time singlehanded to apply 7 11m long pieces of carbon, all the consumables and getting the bag tight, so it was a bit exciting to see how well it had worked.

After making the necessary measures I started to cut the top of the mast clean.  I cut the top at 6 deg relative to the axix of the mast in order to compensate for the log and get a horizontal top.  I used a regular carpenter's saw ant that worked well.

A closer look at the mast section.  Note this is the top and the UD fibre area is half the thickness of below the hounds.

I started fitting the top U-shaped insert that carries the main halyard sheeve and the termination of the 2:1 halyard.

Then I sat nup the mast with the trailing edge up to make the slot for the sail bolt rope.  This is the jig for cutting slot with circular saw. I finally got my 12mm drill back as well, as it has been sitting in the bolt rope tube at the join since building the mast.  I put it in to align the two pieces but couldn't get it out afterwards.

From the other side of the cutting jig.

After cutting I had to sand the track well.  I used a 10mm round steel inside the tube, with sanding paper going in one side and out the other, turning around the steel.  Then, when  pulling the paper back and forth the slot is being rounded well on the inside, in the transition between tube and slot.  I think this is important in order to get the sail run smoothly in the track.
I also glued in reinforcements on the inside of the track at the top before glueing in the U-shape. I would not like to pull the boltrope out of it's track.

Then I made the top cap on a piece of foam as mold.  This will serve as attachment for the wind transmitter.  I will have to make it removable some how.

I did some fine cutting at the lower end, dug out the foam and filled with fibre reinforced and thickened epoxy.

At last, a kind of an overview shot, showing the mast from hounds down, leading edge up.

No comments: