Laying up first mast part

After the successful release of the rudder from its mould, I had no more excuses to postpone the mast lamination.  So today I finished the 5 layers of release wax and started cutting the carbon.  The first layer in the mould is a triaxial stitched of around 630 g/m^2 followed by a 420 g/m^2 unidirectional.  The fabric is really compact and will make a very nice laminate.  In between every layer I put a narrow strip of 0/90 to reinforce the mast track, I would hate to have the main sail pull out of the track when pulling in the sheet.

 Cutting triaxial and unidirectional carbon.  A special thank to Thomas for giving me the excellent Chinese tailor's scissors.

 The extra reinforcing layer outside the boltrope track tube

I placed the inside layers as well before sticking the foam core in.  The inside laminate is the same as the outside but in reversed order. Boltrope track reinforcement between each layer.  Then the tube was placed, and the foam put in between the two layers of unidirectional. I used a lot of clamps and 3M spray glue to keep the different fabrics organized.

 Most of the lay up in place.  Need to cover the inside of the boltrope tube. There will be fitted aluminum T-bars on top to create a recess outside the mast and a glue flange to glue the shear web to.

Just another view of the same

I will continue with peel ply, release film, resin distribution media and spiral tubing for delivery and suction, and then wrap it all in a bag.  The boltrope tube lumen has to be open to atmospheric pressure to avoid collapse and resin filling.  We'll see how far I get this evening.

Popping out the rudder

Yesterday I was able, with the help from gravity and a friend, to pop the rudder out of the moulds (by bending the mould as the rudder itself is inbendable).  It was indeed a pleasant feeling to hold this 1650 g extremely stiff carbon foil in my hands.

Rudder just left the mould

As opposed to the last rudder, there was very little damage to the mould this time, almost negligible as the area affected is not a part of the rudder surface.

 Small damage near the tip of the blade

Also, this was a couple hundred grams lighter than the last one.  The reason for this is no doubt that it was manufactured with one laminating step less, ie the foam was attached to the skin in one operation, hence less epoxy needed.  The finish was the same almost perfect, and a clear coat would definitely be no problem.  I will paint the rudder.

Trailing edge trimmed to give roughly the correct size

Joining rudder halves. More mast preps

This is what one rudder half looks like right out of the bag.  This time I did both the skin with structural reinforcements and foam core in one go, leaving the centre core area untouched.  The core was pre shaped to fit the skin, but left high.  The HD inserts was left even higher as can be seen here.

Then, using a router in a home made jig, I cut everything back flush with the centreline.  Then I digged out the foam to give room for the centre core.  This also gave me an extra quality control opportunity, as the core to skin bond was inspected and tested all along the recess.  It was of excellent quality.

Here, the two halves seen in the background as the core is being laminated with the last piece of carbon sleeve visible on the vacuum table.  After this I applied thickened epoxy (cotton chop/micro fibres) to the recesses and wetted the foam surface of both halves before I placed the core in the recess and joined the two halves.
Holes are CNC'ed in each corner of the mould for alignment, and the halves were bolted together and then placed on the table in order to cure under vacuum.

You can see here the rudder moulds under vacuum.  Bolts extending under the breather.  Object is to compress the two halves together, and make sure the whole mould is as straight as my vacuum table.  Please note the pencil added inside the bag, hopefully it will take notes from the process.  On top mast plans and jib halyard block, the builder obviously already in another mood.  The observant reader may have taken note of the wall now seemingly very close to the table; this is not the fact as it is the opposite: The table has been moved closer to the wall in order to accomodate carbon cutting in front of it.

The mast building is coming up.  I decided it was enough of filling and sanding.  The original finish of the moulds was obviously not perfect, and still it has proven to be a very effective piece of engineering, so I decided to move on.  Grey is my added fairing compound, black is old gel coat, now wet sanded till my shoulders hurt.  My fingers tell me it is ok.

This is a close up of an area earlier published on this blog, now feeling quite fair.
 

I cut the foam for the lower aft half, which will be the first part to be infused.  I'm using 8mm pre perforated Divinycell H100 foam core for better panel stiffness (buckling resistance) on the less curved parts of the mast. I will use this as a core for the central shear web as well.

The sail track insert is from electrician's PVC tube that come in maximum 4m length and has to be extended.  I don't need  much strength in the join, as that will come as a part of the lay up, but air tightness is absolutely necessary for the infusion process to work out.

Trial fitting the foam panels for the lower aft half. At this stage the foam was also cut to fit the molded in pre bend of the track.  After this photo was taken, the foam was removed, and the mould is worked over with the mould sealer.  Aluminum T-profiles that will be used for making glueing flanges and -recesses was also cleaned. 

Five layer of wax is next.  I'll have an idea how well this release system works tomorrow, when I remove the moulds from the rudder.  That will hopefully be a bit of fun. I have to do the rudder finish and get on with the rudder case in order to be ready for last shaping of hull before filling and fairing starts early December, hopefully.

Trying to decide on furlers

I have to decide on which furlers to use on the different headsails.  There are several nice furlers on the market, and choosing the right one might not be so easy, although there are probably several right choices.

The chute is the easy one, only Facnor have one as far as I have been able to find out, so this will be the Asym FX 1500.

The jib is restricted by the size of the hole in the deck, and the below deck compartment itself.  This rules out the Colligo.  Precourt rules out themselves by not responding.  Facnor have decided to rule out their FX series and recommends the wire luff furler, in which I have no interest.  I'm going with the Karver KF-1 here.

The contenders for the screecher are the Karver, the Facnor FX-900 and the Selden CX-15.

The fact that the different manufacturers provide different types of technical information makes it even harder.  And what about the swivel and halyard, 2:1 or not?  I would have loved it if Colligo made a smaller model of their light weight swivel with 2:1 static block.  Any input would be most appreciated.

Laminating rudder halves

I got most of the carbon cut the other day, and did the rest today.  The mould was sealed earlier, today I applied 5 layers of wax, using Chemlease PMR-90 that I got for the mast.  It's supposed to have a very good release.  I'm anxious to find out....

The wax have to be left to cure between each layers.  During the curing time I prepared plastic cutting patterns for cutting the carbon for the mast

Doing the rudder halves as a wet lay up, there was no room for photographing the process.  Here are the carbon skin, the UD reinforcements and the foam core with cut back and HD epoxy mix along the trailing edge wet in the moulds.

Consumables added and a perfect vacuum making sure everything is perfectly bonded to each other. Next step will be routing the foam and skin edges back to centreline level, and then remove foam to allow for the central core which will be added wet as the halves are joined.

Fairing of the bow pole 

Small steps forward

The moulds are soon ready for mast production.  While the fairing compound in the moulds harden, I do a bit of other stuff.  Here are the finished bow pole attachment points.

And the rudder foam with HD inserts.  I will make this rudder in a slightly different manner than the last, laminating skin and core in one go, then removing foam for central core before joining.  More to come soon.

Washing, sanding, washing, filling, sanding, washing

It has been difficult finding time again for a few days, but the moulds are getting better and soon ready for use.  First, after a thorough wash, I wet sanded the moulds to get an impression how bad they really were.  The leading half is not that bad, but the trailing half had a lot of damage to it.  It almost seems they forgot to wax it in several areas before the last shoot.

Then, after soap and the acetone washing, I started filling the imperfections and damages.  This is now sanded down again (hard work sanding epoxy filler inside a mould) and I will have to do one more fill in a few spots.

I also laminated the sides of the carbon anchors for bob stay and screecher tack on the bow pole.

And the last lamination inside the "ears" was done.   After placing the carbon inside, I inflated a balloon to keep it tight to the underlying laminate.  Worked well.

Hopefully, November will bring a mast to the workshop.