Thread: GIS Build in Queenstown New Zealand

I'm thinking of following Compass Projects suggestion of doing the sail with three evenly spaced reefs: First at 60cm, second at 120cm, third at 180cm from the foot. Third reef ends up with a bit more sail area than Mik's drawing, possibly makes it a bit more useable.

I figure I'll carry a small (a couple of square metres or so) spinnaker of nylon or polytarp for going downwind in 30+ knots. If I get caught out in extreme conditions and have to get to windward, I'll be on the oars. (It's amazing the stuff you can make progress into on the oars or a paddle if leeward is 5000nm to Chile)

I'm curious if anyone has any opinions on this, pros and cons.

Ian

The C spars look very well made having seen a number. But will they have the right flex, strength where you need it etc.

Did you record the yard flex?

Originally Posted by Compass Project

The C spars look very well made having seen a number. But will they have the right flex, strength where you need it etc.

Did you record the yard flex?

Hi Clint,
The mast just has to be strong/stiff enough. We spec'd it at stiffer than Mik's wooden box section, then added extra internal sleeves through the mast partner area so there's a full 5mm thick of carbon through this area. Mik's is over-engineered already, so we should be fine at about 30% stiffer than the wooden ones at the base.

Yard flex data: It bends 20mm supported either end with 10kg hung off the middle, which is exactly the stiffness I specified. It's twice the stiffness of any of the wooden yards people have made to date, so it will be interesting how that goes in practice.

The people who made the mast and yard are 18ft skiff sailors as well as spar makers, if you went to a National or European Championships in any of the development classes which allow carbon masts, you'd see a fairly high proportion of the top boats with their gear on them.

I need to get the wooden bits finished so I can try them out!

Ian

I have added that data to the FAQ.

MIK

Originally Posted by IanHowick

I need to get the wooden bits finished so I can try them out!

Progress is happening on the wooden bits, I took my big (5200x150x50) piece of Vic Ash to the joiner yesterday and got it ripped/thicknessed to all the thin pieces I need. I'd spent a while contemplating doing it myself with the skill saw and a guide and a new thin kerf saw blade, but having seen it done properly, I'm glad I paid the joiner!

If you're getting big stuff ripped down to lots of small stuff, it's worth finding a joiner with a big band saw that can rip timber and then dress it on a sanding thicknesser. I was contemplating losing 5mm to the circular saw kerf, then 1.5mm each side to the thicknesser. The band saw kerf was 3mm, and the sander took less than 1 mm to get a finished surface, so a lot less expensive timber turned to dust.

I'm doing my inwale stringer from 12mm Vic Ash, the gunwales on the outside of the ply will be Paulownia capped top and outside with 7mm Vic Ash, the other places where the Paulownia can take a knock it will also get a cap of 7mm Vic Ash.

I got some Jarrah knocked down thin at the same time, I'm going to try making a couple of blocks of the stuff, possibly with the pulleys made from HDPE, possibly I'll try a pulley turned from wood as well.

Another development - Blanche will get a carbon mast. Richard Harvey (UK) has just orderd one identical to mine from C-Tech in Auckland. Looks like he will be the first to have one in a GIS on the water, so we can await his report on the differences reducing a 25 pound mast down to 6.6 pound bring.

Ian

I can't wait to see your boat. It is going to look very cool with the cappings.

Jarrah blocks look really cool, but they will be on the heavy side. However they WILL be stable and Jarrah will guarantee that they keep turning forever! Have you got any hoop for these? Maybe make one or two for comparison. Some of my hoop was really hard, like the planks I used for my knees, and a sharp hand plane just skidded off it.

Interesting - I will contact Richard to see how much it will cost him landed. It seems that doing things in our dollars rather than Euros or Sterling helps keep the costs down.

Though I am being hammered a bit by exchange rates going the other way - I think we tend to just do things cheaper.

MIK

Originally Posted by Boatmik

Interesting - I will contact Richard to see how much it will cost him landed. It seems that doing things in our dollars rather than Euros or Sterling helps keep the costs down.
MIK

Freight to the UK was a little over NZ$300 including packaging and them taking it to Auckland airport to put on the plane. It probably looks better converted to sterling.

Richard called around a couple of carbon composite manufacturers in the UK, but no one was interested.

One good thing about importing things from another country, often you save paying the country of origin's sales tax/GST, and if you're lucky it goes through your countries customs without attracting import duty or sales tax, so ends up cheaper than if you were in the country where they made it.

Funny also what things cost more and what cost less, my sail from a NZ sailmaker will cost about twice the price Duckworks lists for their GIS sail, is this indicative of sailmaking prices in the USA, or is the Duckworks sail an especially good deal?

Ian

The Duckworks sail is a reasonable deal.

I do get the sense that sailmaking is a more routine thing in the USA than here - all the lofts seem to be very professionally focussed with racing being the make or break.

I get the feeling it is pretty similar in the UK.

In the USA I think some people drift into sailmaking because the like making sails. So they tend to price a bit like .... small wooden boat designers.

Or might just be the huge amount of competition - business competition - keeping prices down.

MIK

Hi Ian

How are you planning to attach the fittings to your spars? I'm was wondering whether some spectra loups could be epoxy/glassed or epoxy/carbon taped on? That way you don't need to drill any holes and they can be sealed up. Once you have sorted out where the halyard attachment will be, you could do the same there.

There might be other solutions, but I would probably plan to go quite close to the existing Goat rigging method.

A lot can be done with simple cow hitches around the spars.

Four the outhauls on the smaller spars and halyard takeoff for the mast it would be possible to make up carbon fittings out of tow or just glue in wood blocks - which would not need to be large - so holes could be drilled or fittings attached.

The ends of the yard and mast should be sealed anyhow ... so to use the same blocks for fittings might make the best sense.

Will the ends of the spars need some tape around them to prevent them from splitting? My guess is not with properly manufactured spars like these, but carbon spars have been prone to splitting at the ends in some cases.

MIK

Originally Posted by Boatmik

There might be other solutions, but I would probably plan to go quite close to the existing Goat rigging method.

A lot can be done with simple cow hitches around the spars.

For the outhauls on the smaller spars and halyard takeoff for the mast it would be possible to make up carbon fittings out of tow or just glue in wood blocks - which would not need to be large - so holes could be drilled or fittings attached.

The ends of the yard and mast should be sealed anyhow ... so to use the same blocks for fittings might make the best sense.

Will the ends of the spars need some tape around them to prevent them from splitting? My guess is not with properly manufactured spars like these, but carbon spars have been prone to splitting at the ends in some cases.

MIK

Hi Mik, yes, thanks, I think I have it figured, definitely the ends of all spars plugged and no holes drilled in the spars at all. I'll glue a small wooden block with a longways and crossways notch in it at the throat end of the yard, put a cord whipping right around the spar and through the eyelet in the sail to hold it on there. The other end will have a "sock" made of nylon climbing tape which fits over the peak end of the yard with the outhaul attached to it.

The masthead halyard block attachment will be a similar "sock". I'll add an extra loop on it for the gennaker halyard. (Wait till you see the retractable bowsprit and hiking gantry I've ordered from C-Tech)

The halyard loop on the yard will be a cowhitch, same as standard.

Yes, ends of the spars are already taken care of as regards splitting - the spar maker put an extra layer of prepreg biaxial tape on the ends of each spar, if you used off the shelf tubing, you'd have to do something like this yourself.


Pictures of what I'm planning soon.

Ian

Originally Posted by IanHowick

Hi Mik, yes, thanks, I think I have it figured, definitely the ends of all spars plugged and no holes drilled in the spars at all. I'll glue a small wooden block with a longways and crossways notch in it at the throat end of the yard, put a cord whipping right around the spar and through the eyelet in the sail to hold it on there.

Sounds good, as long as this attachment firmly fixes the throat so that it cannot move downward under downhaul tension one little bit.

Waterproof sealing of the spars is GOOD too

Further to the attachment points on your carbon spars, here is the Merlin kicker attachment. This solution spreads the load a bit better than a lashing.
Attachment 150107

I also like the simplicity of the Antal rings. Low friction and no moving parts. I just know MIK will love these!
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These snap-loops are also nice because they are easy to undo. They'd be easy enough to make as well.
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