Sunday, November 21, 2010

Update form a sail at lane cove,

The boat performed fairly well on the weekend, with the hull keeping up with the faster boats upwind and showed good downwind speed if not equal with the faster cherubs. Breeze was around 10 knots with gusts of 15. The sails were from my old boat and did not fit particularly well. Especially the spinnaker due to the further aft mast position and rake, So i needed to place strops on the tack and head to get some sort of "slack" in the luff, which produced a difficult to handle spinnaker.

With this in mind the rig has basically be placed in the boat using generic values of rake and an unknown rig tension, so I'm hoping that with some tuning and re-cutting/ new sails it will prove to be a very fast boat in medium to heavy airs.

Cost Update:

Preliminary cost of the project is as follows:

Jig materials - $550
Hull materials - $3950 (Resin, carbon, foam, consumables etc)
Power tools/ consumables - $400
Fit out - $3550 (CST rig, stays, fittings etc)

Total Cost - $8500

Although this cost is likely to be around $9000 after a few more ropes/fittings, also sails need to be considered.

I will give a more detailed cost breakdown further down the track.

Monday, November 15, 2010

Well she has finally managed to get out onto the water. With a large amount of work being put in over the last couple of days she finally got a sail in.

The helm felt good but i will pay more attention to it on the next sail and try to work out if the rudder balance of mast rake/centre board position needs changing.

The boat responded well upwind when there was a decent gust, but did bog down a fair bit in the lulls. Though i think with a bit of careful fore aft trimming we will be able to solve this. The hull seems to move quit nicely through the chop while down wind it didn't seem to have some massive urge to nose dive, although we were only hiking (maybe 15-20knot gust) but it did feel quick.

The cockpit layout and rig position so forces the crew to sit further aft in the boat during tacking/gybing etc, which could lead to a problem of the transom sinking a little during tacks etc, which would mean it will be slow out of tacks.

In conclusion I'm very pleased with how the boat turned out and now my crew and I will need to focus pretty heavily on the fore-aft trim and setting up the rig position/rake to make to boat work well.

I'll let you know how she goes against some other boats hopefully next week.

Saturday, November 6, 2010

Fit out has begun..

Started to fit out the boat over the last couple of days with the help of the old man. Once our fittings arrived from ronstan we double check the dimensions of each fitting and its location and made a bolts list for each fitting. This resulted in several different lengths of M4 or M5 (metric) bolts being used over the whole boat in order to 1. keep weight to a minimum, 2. prevent bolts protruding into the spinnakers chute/bow pole area etc.

The bolts used were 304 grade stainless as our local store did not supply 316 grade, without ordering them in boxes of 100. So this just means that good care of the boat is needed to ensure that salt water is washed off when ever possible to minimise corrosion... on the plus side 304 is stronger than 316 grade and slightly cheaper. All up our bolt order for the bolt cost approx $100, which included several shackles and a 50 x 6mm tow ring.

All fittings on the floor and side tanks are attached to be boat by taping threads into pre-located fibreglass or carbon fibre "blocks" laminated into the floor.

The mast step is made from 2mm thick 6061-T6 aluminium, which i tig welded in the workshop at uni. The side stay and lowers mounting bracket is made from 2mm 304 stainless steel, which i also made in the workshop.

The overall rig length is 6.49m with a goose neck height of 640mm above the sheer (1000mm off the floor). I will upload a "plan/drawing" of the finalised rig once it is completed.

We roughly placed the rig into the boat this afternoon to try and estimate the stay lengths required. To do this we set the rake on the mast so that the tip was vertically above the back of the centreboard case (or equivalent distance in our case) as is a generally rule of thumb for cherub rigging. From here lengths were taken as were additional measurements of all rig fitting locations so that i can create a spreadsheet to calculation stay lengths and the effects of rake change/mast step position on length etc.

After the initial rigging today it looks like I'm going to have some "fun" trying the make the sail plan work for the boat. The jib requires a very long foot due to the mast position (6ft from the bow, as opposed to 5'6-8" or so for normal boats). I anticipated this and placed a large forestay mount on the boat allowing it to come back about 120mm, so I'll let you know what i can come up with.

Sunday, October 31, 2010

After many hours labour the hull as been wet & dry sanded and polished back to a smooth gloss with a few little patches showing on the side that the colour wasn't quite as thick as we once thought, but at least that means it will be light.

Since then we have finished off the cradle and put the boat back upright. The floor was then painted with white two pack paint with a roller. Three light coats were first applied wet on wet to get an even colour across the floor. To get the grippy finish a mixture of "Norglas" grip additive and caster sugar where added to the white paint. This slightly thickened mixture was then spread over the floor with a roller.

Since uni work was handed in last week its all hands on deck to get her rigged and fitted out so we can get her wet at least once before the Belmont state titles. Most of the fittings have arrived and will begin to be place on the boat mid week. A bolts order will be made early this week once we have the fittings and a new s/steel mast step is in the works to be welded up before the weekend.

Sunday, October 10, 2010

Hull has been sprayed

Finally got a chance to spray the hull and decks this weekend. The colour is Waratah red and flowed from the 1.4mm nozzle gun very well with no reducer. We ended up using 2.5 liters of colour (as opposed to 1.5L that i calculated from the data sheet) the main reason for this is that we decided to do a third coat on the hull from chine to chine to try and smooth out a little bit of orange peel.

Next step is to use a roller the put the white paint on floor and put in the aggregate to make a grippy finish on the floor. Then the do the final trimming pieces such as clear two pack paint on the rudder gantry, rudder, centreboard and transom bar.

Monday, October 4, 2010

Primer on topside of hull.

quick update:

The hull has had a further two coats of primer and spot filler and looks pretty good if i don't say so myself. It took a lot of torture boarding and relentless sanding to get there, but i think the hull is as smooth and fair as we are going to get it. We changed over to an older spray gun we have that has a 2.0mm nozzle and we thinned the primer 15-20% with reducer and it went on a lot better than our first coat with a 1.4mm nozzle and only 10% thinner.

We had hoped to spray the hull with colour over the long weekend but the rainy weather (high humidity) has set us back. So instead we flipped the hull over and began fairing the decks and cockpit with Q-cells/ epoxy then spot filler and we gave it a coat of high build primer this afternoon.

At this stage it looks like the topside will take one more pass with some spot filler to fill a few pin holes in the side tanks and help fair in a few more joins etc. Then a final primer coat and we should be good to spray the topsides as well. Therefore potentially next weekend could be a big weekend of spraying and we might be able to get all the colour sprayed by Monday next week (weather depending).

We also reweighed the hull before adding the primer this arvo, it came in at 43.5kg, with bowsprite and rudder gantry in place. So it still looks like a may end up with some lead in the boat (touch wood!).

The new carbon rig is still a few weeks away, as are the fittings from ronstan so we have decided to skip the first round of the state titles in two weeks time. This is probably a good idea as well because uni work is starting build up for the end of October. Our next aim is to have the boat on the water by the end of October so we can get some practice in before the second round of the states in November.

Here are some images of the progress:

Sunday, September 26, 2010

We put the first coat of primer/ high build filler on the hull today, which went fairly well. Although we need to play with our spray gun setup and try to get more of a "Wet coat" effect as we had a fairly dry/dusty effect coming from the gun, which took quite a long time to get a decent coat over the boat. On the next coat we might try the larger nozzle size (2.0mm) as opposed to the 1.4mm size on the current setup as well as adding more than 10% thinner to the primer.

We are planing to the spray the colour next weekend.

Wednesday, September 22, 2010

Hull laminating has been essentially completed, decks and side tanks are laminated in place as are all the hard points for fittings. At this point the hull weighed in at 41kg the minimum weight for the class is 51kg. This gives us 10kg for paint, filler and fittings.

I have worked out that i need 1.5L of (Waratah Red) colour paint for the hull, deck and side tanks and 0.25L for the white floor so i have ordered a bit more than this for wastage and spare paint in the event we need to do a significant repair down the track.

So far we have two three coats of "bog" (thickened epoxy resin with Q-cells) over the hull and "torture" boarded two of these coats and already the hull is look a lot nicer and fairer. Once we are happy with the shape or "fairness" of the hull we will spray a two part primer/filler to fill any left over small holes. Then we will be onto the final paint topcoats.

We have already ordered a new high modulus rig from CST and approx $1500 worth of pulleys, cleats and fittings from Ronstan. At this stage we are planing to be at the first state titles rounds in mid October in some form or another. Although there is still a lot of work to do associated with the centreboard case, vang system and fit out.

Saturday, September 11, 2010

side tanks are in!

Hi all,
Finally its starting to look like a boat!Side tanks have been glued in and laminated into place. The port tank will act as a spinnaker chute, helping to keep a clean cockpit and the stb tank will be a bouancy tank.
(this is a view down the spinnaker chute from the bow)

All of the hard points have been laminated into place, which is 5mm thick fibreglass plate, with approx 4 layers of carbon over it on the floor. These will then be drilled and tapped for an M5 or M6 bolt to attach fittings.
After re-weighing the hull with the following; sides glued in, foredeck on, gantry in the boat. The hull came in at 39.5kg which isn't bad, but i doubt that we will make the 45kg lower limit for the class (hmm that 6kg's of lead would have been good!)
This is an image of me trying to work out how to mount our vang system. The blue pen lines are a radius out from the centre of the mast, while the other lines are different layouts of connecting the system. The lay-out above with the green string appeared to follow an arc from the centre of the mast the best, meaning that when we was our main out and out boom angle increased the distance between the mast and boom vang will remain the same, giving a constant boom vang tension. This whole set-up will be discussed in more detail once it has been built

Monday, August 30, 2010

Just weighted the hull.

currently at 35 kgs that includes:

  • Hull
  • Floor glued and laminated in
  • 1 side tank
  • Bulkheads
  • bowsprit structure
  • transom bar
  • Gantry
  • Carbon blocks for fittings (almost 0.5 kg)
The class minimum weight is 51kgs including control lines and bowsprit.

So i figure 5 kg more in glue and fibreglass, 3-4 kg more in fairing compound and primer allowing 7 kg for fittings, bolts, ropes and foot loops.

So at this stage its looking like i should be able to fetch the minimum weight with not too much hassle unless the hull requires a lot more filler than first thought or paint.

Sunday, August 29, 2010

Current progress

This is the side tank under vacuum on the side tank mould. I was quite happy with how this process worked. Using only 5 supporting frames and a 3mm sheet of melamine coated MDF as the mould surface the shape held very well, even under vacuum there was no distortion or warping.
This is a roughly trimmed side tank, this will be going on the port side and will house the spinnaker to keep the cockpit neat and tidy. The mould gave a good smooth surface which should be easy to paint straight to will minimal filling and sanding.

This is the "tension member" that I have Incorporated into the hull fit out. The idea behind it is to help triangulate or form a space frame between the mast step and stay mounts to help increase the stiffness of the hull and rig, which hopefully will help to reduce fore stay sag when sailing, which may ultimately allow for a wider range of rig tensions to be used. The member only weighted 280g so hopefully the advantage will be worth the small weight penalty.

This is a quick image of the fore stay mount attached to the top of the bowsprit receiving tube. The plate is made from two layers of 2mm thick 0/90 deg woven prep reg plate, then extra layers of 0 deg fibres to deal with the tensile load and +- 45 deg fibre to resist "shear out" of the fore stay pin

This is a photo of the rear bulkhead that supports the bowsprit receiver tube. The bulkhead is glass and foam with local carbon reinforcement to help distribute the load to the hull. The joining tape for the bulkhead to hull joint is laid on the -+ 45 deg to provide good shear strength in the joint.
The floor has finally been glued into place using Q-cells and epoxy.

The centreboard case was opened up and the polystyrene foam was dug out.

This is a photo to try and show the collapse that we found in out rudder. That surface was the upward facing surface in our mould when we used to expanding epoxy foam. It looks at this stage like it was a large air pocket or void which has collapsed for some reason after it was made. Although we are uncertain why it collapsed as the carbon skin should want to stay in its moulded shape so they must be some sort of suction or residual stress present to force it to collapse, time will tell...

Also completed but i don't have any photos at this stage, the port side tank has been fitted, starboard side tank has been laminated, rudder gantry fitted and trimmed, spinnaker opening shaped, spinnaker chute has been laminated and carbon plates for fittings have been cut.

Bring you more photos shortly.

Thursday, August 19, 2010

Quick update

Above are a few images of the new side tank moulds. They were made using five 16mm MDF templates glued to backing strips then a sheet of 3mm melamine coated MDF was bent over the frames and glued down. Hopefully this set up will be able to resist the loads put on it from the vacuum bag, only one way to find out i guess. Plan is to pop one of these out this weekend.

Above is an image of us doing a rough fit / check of the foredeck and floor panels. Both of the these were pulled straight from the CAD model and fitted really well straight away. The foredeck template was also useful in highlighting how much the hull actually moved / spread out once it was removed from the jig.

This is a photo of the bowsprit receiver tube that i thought would be useful to share. Basically to fit the receiver tube a section was cut out of the bow and a simple bulkhead with a hole cut in it was made to support the back. The section that is on the stem will have a fairly substantial laminate (3-4 layers of 300gsm UNI + 1x 200gsm cloth) wrapping over it and down both sides of the bow. The bulkhead will then have a few strips of uni and some cloth to take to load to the gunwales and down lower on the sides of the hull. This area is going to have a few more little tricky bits and ideas thrown at it over the next couple of weeks so I'll keep you updated.

Tuesday, August 10, 2010

Floor ribs laminated in, centreboard case laminated in, bulkheads laminated in.

Next on the list:
  • Fitting bowsprit snout
  • Fitting floor
  • and building side tank moulds
I'll through some photos up shortly

Saturday, August 7, 2010

quick update of todays work:

Bulkheads glued in
Floor ribs glued in
Centreboard case glued in

Plan for tomorrow,
Laminate in place all of the above and trim/fit floor and mast step area.

Tuesday, August 3, 2010

mucking around with paint schemes

current thinking is red hull/deck/side tanks with white floor, carbon fibre finish on; transom bar, gantry, rudder box, foot rests. Then black gunwhale and fore deck grip. P.s. i'm also open to suggestions for paint schemes and names.