Monday, February 28, 2011

Last mast part demoulded. Very good result.

It seems like I'm getting better and better at this. Easier demoulding, easier removal of consumables and better surface finish. This part let go of the inserts very easily, and the halyard recesses came out close to perfect. It is trimmed and peeled and weighs 8,1 kg.

Continuing serial production of carbon tangs. Every tang is made in two steps; first the central glass piece and the perimeter uni carbon spread uot in the mast shaped piece, then the layers of triaxial each side of the tab and into the mast shaped part. I need 5 tangs in three different sizes to fit the mast. Three down, two in production. Here step two curing under pressure

This is what comes out of the moulds

Genoa tang trimmed and in position

I started the mast crane. It will be a U shape with the main halyard sheave inside, and a bolt for the halyard dead end. I will use 2:1 halyard to lower compression and clutch loads. Crane under vacuum.

The unprocessed U-shape.  Approx 3600 gsm.

I made up the 25mm inner diameter carbon tube with high compressive strength lay up that will make a transverse pass trough the mast and serve for custom synthetic shroud system from Colligo Marine.  Wrapped around a steel tube, using peel ply and tape to compress during cure.  A layer of plastic closest to the steel, used for sliding off the tube.  I didn't find my silicone spray that I use between the tube and the plastictoday, so releasing was quite a struggle. Would normally slide off quite nicely.

Finished 25mm x 3mm carbon tube

Sunday, February 27, 2011

Last quarter

I was at Røros a couple of days, but still have managed some progress.

I had to make new inserts for the halyard in recesses. These were made faster and turned out better than the last ones, funny how practice can make you better.

They were covered in packaging tape, and tacked to the mould with a strip of vacuum bag rubber tape.  Whether that was a good idea will be answered tomorrow.

All carbon and foam was placed before I left for Roros, extra reinforcements were put in for shrouds, stay/sail attachments and mast crane.

I got all the consumables placed this morning (peel ply, release film, RDM, spiral tubes and vacuum bag) and pulled an instant 97%.  I did not manage to get better than 99% though, and I infused at that vacuum this evening.  The epoxy and the mould inside was preheated to about 30ºC.  The whole process took about 16 minutes, then extra heating was added and I continued with other things until gelling.

Moulds being prepared for mast tangs. In the background mast base plate starter.

Series production started

I made a 5mm carbon plate as the core for the mast base. Down left the cup covered in a couple of layers carbon as a bonding surface for mounting in the plate.

The cup being inserted and glued in place

Detail of jigsaw blade after cutting three tang glass inserts.

Tuesday, February 22, 2011

Centre web

Wet lay up and vacuum bagging on the workshop floor. 635 gsm triax carbon - 15mm H100 - 635 gsm triax carbon. Upper and lower parts side by side in the bag.

Evening shift

I mounted the mast raising eye.  Bedded in micro fibre saturated epoxy, I made sure the parts were kept firm together:

Then a piece of carbon was laminated inside, covering the inside part of the tang:

SS tapping plates for the clutches and horn cleats. It really hurt to put in all that weight, but I didn't see any viable alternatives, and it's down by the foot.  Bedded in micro fibre epoxy until gelling.

Then I filled the edges and covered with a layer of glass fabric.

Also a piece of glass at the halyard exit for chafe protection.  Showing inside of mast.

I was about to laminate the centre web, using the floor as a vacuum table, but I decided to postpone until tomorrow. Maybe I'll concentrate on the last infusion tomorrow though.

Monday, February 21, 2011

Carbon mast tangs Mk II

I made the Mk I carbon mast tangs a couple of moths ago, and it turned out quite OK, but not good enough.  So I developed the moulds to be able to take them the little step further.  I have now made the first Mk II tang and I'm very satisfied. This will be the mast raising eye.

Step 1:  The central 6mm thick fibreglass lining is placed between the moulds and secured with a bolt trough the moulds and the fibreglass.  This way I was able to use lots of force to compress the UD carbon around the glass tab.  The ends of UD carbon is spread like a fan and placed between two layers of triaxial carbon in the mast shaped part of the mould.

Step 2: De moulding and preparing two extra layers triaxial each side of the tab.  Hole for the bolt visible here, as is the ready cut triaxial for next step.

Wet lay up, and the three part mould is assembled again.  Home made "screwing clave" providing superb consolidation during cure:

De moulded and trimmed.  Using a router bit to make bellmouth hole for lashings.

Mounting: A rectangular hole made in the mast wall.  Peel ply removed.  The part will be bedded in micro fibre thickened epoxy and laminated over from the inside.  The loads should be well distributed to the mast wall without point loads.

Showing how the headsail blocks will be attached.  Not on this tang though, as this will be for the mast raising wires.

The headsail and headstay tabs will have a slightly different shape.  Fibreglass inserts in production:

Mould repairs

I cleaned up the mould, and the damage didn't look that terrible.  Several fields of dry, hairy glass though, so I decided to re saturate the surface with epoxy.  Covered with peel ply to keep it where it was needed.

The epoxy filled quite a bit and not much left for fairing compound after removing the peel ply.

After sanding back the epoxy coat, I filled with SP S'Fair 600.  Sanded down to 600 grit and re applied Chemlease mould sealer.  Ready for wax and the last infusion.  But first I have to make new halyard exit recess moulds and come up with a better way to attach them.

Friday, February 18, 2011

Carbon wing mast: Demoulding lower leading half

Vacuum resin infusion produces quite a bit of garbage.  These are the consumables removed from the mould.  The peel ply is still on.

The Chemlease release wax works great.  So great it is not possible to attach a tape to a waxed surface.  That is why I placed the inserts for the halyard out recesses prior to waxing.  Unfortunately, this demonstrated quite clearly, unforeseen, the effectiveness of the release system.  This is the mould after removing the mast part. The lack of gelcoat is unfortunately obvious and I have begun the mental preparations for repairs

The part itself was however removed without any signs of damage.  A very good result, part weighing in at 6,6 kg including peel ply and untrimmed, total weight of mast so far 28,6 kg which makes the goal of <50kg seem acievable.  We were very eager to see what the complete wing looks like, so I lowered the trailing half from the ceiling, put in the foam blanks for the center web and placed our latest creation on top.  Ståle demonstrating his satisfaction (and serves as a scale):

Another view of the complete shape, lower part of the mast, that is.  I got those "so what will happen when at the dock in a storm"- thoughts again.  I guess time will show. I expect the mast to work very well as a Try sail.

This is a close up of the starboard halyard out recesses.  Plan is to make a circular hole in the far end of the recesses.  Halyards will be led to clutches and secured with horn cleats at the bottom of the mast.  Snatch block on deck will temporarily lead halyards to cabin top winches.

Well, guess next up is mould repairs.  Should not be that big job. 

Thursday, February 17, 2011

Three down, one to go

Ståle helped me prepare the carbon, foam and all the consumables, and we pulled a decent vacuum at first try.

We proceeded with the infusion, which went uneventfully. A total of 4,4 kg of SP Prime 20 LV infusion epoxy entered the bag.  This construction, consisting of a heat gun, a non functional fan heater, a sheet of plastic and a sucking fan let us record a maximum surface temperature inside the mould of 49ºC.

Demoulding tomorrow.

Wednesday, February 16, 2011

Almost prepared

Preparing for infusion of the lower leading edge half.  I have decided placement of halyard out, rope clutches and horn cleats. Carbon, peel ply and release film have been cut.  Foam is cut with recesses for the hardware.

Halyard out mould inserts.  Mould sealer and two layers of release wax have been applied

Release film, peel ply and carbon ready to go in the mould after another two layers of wax.

Some nice French hardware arrived.  Karver KF1 for the screacher.  Identical furler for the jib.

Monday, February 14, 2011

More mast building

Not much visible progress, but I have a lot of preparations done now, so the next infusions are getting closer.

I did the inside join.  Double layer triaxial, 5cm and 10 cm overlap, wet layup vacuum bagging.

Heat treating the bag.

Then I cut all the foam for the centre web.  15mm 100kg/m^3 Divinycell. I have no idea how to laminate it yet.  My vacuum table is 3m long, so laminating there will still be 2 joins on the upper half.  It might be possible to use the floor as a laminating table.  I might laminate one side, and then the other side after mounting, lapping down the UD recess on the side.  Or just plain double side laminate and glue to flanges with micro fibre saturated epoxy.

Using wire to scribe the shape of the mould, I am making moulds for the head sail tabs.  My wife's idea, thanks!

Cutting foam for the leading edge part.  I decided to use foam around the bend close to the join.  This way I can sand down and round off the shape at the joining height.  Mostly a visual thing, I guess.

Thermo formed mast foam

I also made mould inserts to form the halyard in/out recesses

And I was able to get a couple of daylight pictures of the floats.  Snow on deck.  Will definitely be visible on the fjord.