cheap and simple rig

Hey - there 'Plod' where is this place you come from ??? Plodicatia ???

Is the economy there as totally devoid of value as your attitude ???

Did someone get your tampons mixed up with others in this place ???

You do - say above - "Moving on now" We - sure do hope so. Not so nice of you to come - - Here's you hat & coat - don't forget your mobile phone & do close the gate on the way out.

OH YES & please leave quietly - thanks. Ciao, james

 

expected as much... yawn...

have you even bothered to read about the subject matter we are discussing?

Eric sponberg charges for the design, he doesnt build them. Read this, about a free standing mast he designed, and the owners of the boats built it... http://www.sponbergyachtdesign.com/PoohSticks.htm
and another
http://www.sponbergyachtdesign.com/Copernicus.htm

there are more examples like this on erics website...

Rob Denney sells the same advice, engineering, and construction help for his masts. He also builds them, and has a pro builder to build them for people who dont want to DIY... choice is yours...

There a multitude of home builders that have built their own masts, and a multitude of home builders who have built their own composite aircraft, including carbon wing spars - your life depends on these more so than a yacht mast - something else you probably know nothing about because your too busy watching TV...
Its not my job to point out all the examples just to satisfy your ignorance.

All carbon masts are not filament wound sticks either... and certainly not a method a home builder would use to build one!

Have you learned anything yet WUZZI, or is your head still buried in the sand?

 

The technique used to make the masts for Pooh Sticks sure seems clever.

 

I Have my own ideas for constructing a carbon mast via infusion on a flat table type mold, no mandrel s necessary, everything layed up flat and simple with an outer fairing bent into shape but ill save them for another thread... the point im trying to make is this, carbon does not have to be difficult or expensive even for the home builder.

 

If you are not a mind reader, perhaps you should not have claimed that in my earlier post I did "deliberately engage in misquoting" especially when by your account you couldn't be bothered to check whether that was the case. Surely there is no need to abuse someone's honesty in a forum.

This is not a straw man argument. As you yourself agree, those who sell up to go cruising cannot be considered conservative generally. So why would they suddenly become so conservative when it comes to choosing rigs?

 

I don't know if this is a reference to me, but if it is I want to be clear. I am not, nor have I ever been a "professional rigger".

 

Because usually they've decided to put their entire life savings, life and possibly the life of their partner and children on the line by their rig choice.

Of course they're going to be conservative! That rig *has* to stay up and keep working. Prime criterion, way more important than being made of the latest stuff, the lightest or the absolute best performance.

Totally different mindset to racers.

As I'm neither interested in changing a mind that either can't see the point or doesn't want to acknowledge it, nor mindlessly driving up my post count to no good purpose, feel free to have the last word.

PDW

 

Steve Clarke,
An unstayed rig is a small step up compared to going from mono to multi or wood to grp and alloy. And there are now sufficient boats out there to show it can easily be done. A rig with nothing major to break won't need "knowledgable resources if it takes off into the wild blue yonder", so their availability is not a problem. The swing rig in the video is one of many that have been "got right" (for cruisers) at full scale.

bpw,
What is the cost of the timber, glue, fittings and rigging you are using to compare the wooden marconi rig with the carbon unstayed rig? And how much labour would be involved to build and rig it?
The skills involved in building a hollow (or even solid, multi piece) wooden mast are higher than those in a vac bagged carbon mast. You also require many more tools. If you are smart enough to design your own wooden mast, you could easily learn how to design a carbon one.

Richard,
Eric's article is out of date on costs as I have been showing you for some years and as demonstrated by the costs of the rig I quoted earlier in this thread. It is also out of date on sizes. There are carbon masts being home and factory built for every class that allows them and for every boat that wants less weight aloft.

Eric's first unstayed ballestron rig on a multihull (50'/6.25T pod cat, minimal bury, long fore boom) has just been launched. Looks great.

Team Phillips was the largest race cat ever built. It proved that unstayed masts on multihulls are not only possible, but work well. The boat's problems and demise had nothing to do with the rig. Walker Wingsails was an interesting failure, but as far as I know, the unstayed rigs did not fall down, despite their considerable weight. If you want an example of a modern very large boat with unstayed rig, try Maltese Falcon. It has 3 of them, all working flawlessly. None of these boats has any bearing on what Sailor 305 asked for.

Some peculiar things:

What does a 10' long, lightweight racing dinghy with fixed sail area have in common with cruising catamaran rigs?

You "use" pretty much the same amount of resin as you do when you wet it out by hand. But then you suck the excess out and throw it away. Infusion only uses as much as you need, plus plumbing. Infusion saves a lot of weight and time if the job is designed to minimise the secondary bonds and tabbing later on. Designers/builders are only just beginning to take advantage of this. It is part of the reason we can build a 15m/50' boat weighing 0.5T.

Infused glass panels are typically (me, groper, plenty on Google) within a few per cent of 33/67 resin/fibre, depending on resin and fabric type. That is, twice as much fibre as resin by weight. 800 kgs of glass will require 400 kgs of resin vs your handlaid 1100 kgs. 1100-400 = 700 kgs, a 20% weight and $10,000 worth of epoxy saving on a 3.5T 35'ter.

These are not the amounts you will need to buy. 200-250 gsm of resin is needed to fill the core on both methods. Wastage is anything from 5-20% for hand laminating, 1-8 kgs (depends on the plumbing used) per panel for infusion. Plus resin for bog and sealing coats (minimal on an infused panel as the exterior is against a mould or a table, varies enormously on a hand laid one), glue, etc.

The infused panels will need a mould or a table, a bag (reusable), and some garden plumbing tubes and tape. The hand laid will need sand paper, bog and a sealing coat to get the same level of finish.

The hand laid will be done in a day per side, plus bogging and sanding time (days to months). The infusion will take a couple of days to prepare, an hour to laminate and be ready to paint the next day. Plus mould or table build time which could be anything from a couple of days to a week.

2% is sailing at 10.2 knots instead of 10, which most cruisers would not notice. 20% lighter will make a 10-20% speed difference, and allow smaller motors, hulls, rigging etc which will allow even more weight saving/better performance.

Do you have a reference for this, please? It is completely unfounded, in my experience. Some thin skins (200 gsm woven cloth skins on honeycomb cores) do leak, but it is because they have pin holes due to the weave, not because there is too little resin. Bagged/infused panels do not have pin holes.

. Could you name some relevant ones, please? ie not dinghies and unglassed ply boats.

Please provide a relevant reference and an example for the glass content/resin richness claim. ie What is the difference in water permeability between 600 gsm glass laid up by hand vs infused. I have never seen evidence of either of them being anything other than totally watertight.

Other claims you have not substantiated:
In the thread on this topic in the Multihulls section you won't reference negative comments you attribute to another designer. Nor explain why your less efficient in every respect sheet ply boat is faster than his bent ply boat.
From the lightning thread: "I know at least one carbon mast that shattered when hit by lightning, apparently shards of carbon mast pierced the deck".

Could you also tell us (post #24, this thread) how you reef your cruising boat's stayed rig when running square in 30 knots, which is very relevant to Sailor305's question.

Eric,
I disagree about the build difficulty. Anyone who can use a string line, jigsaw/sabresaw, scissors and a vacuum pump could build a carbon spar quite easily.

I agree they need to be engineered, the same as aluminium and timber masts do, but with more variables.

I disagree that this is expensive. The engineering for the mast in the video cost $230 ($700 spread over 3 boats), and is included free in mast plans for boats with the same righting moment.

We include the basic engineering as part of the mast build, as is commonly done on alloy rigs. I expect other manufacturers to do the same as their volumes increase.

Post #24: "The (17.5m/59') mast tube on the 15m in the video (http://www.youtube.com/watchv=8chR6DAFjGA) weighs 120 kgs: 50 kgs of carbon ($50 per kg), 18 kgs of glass ($10/kg) and 52 kgs of resin ($18/kg). Materials cost $3,700. About another $1,000 for the consumables, bearings and all the fittings. Less than 100 hours work for the tube, using techniques similar to those used to build the rest of the boat. "

Plans for the tube and fittings, including all the email help you need, are $500. The same plans will enable you to build rudder shafts, beams and booms.

How does this compare with the cost of an alloy mast, it's fittings and standing rigging?

Apart from the vacuuming, the only skill required is cutting shapes in mdf, lining them up with a string line or straight edge, some hot melt gluing and cutting fabric.

You do not need a mandrel to build them. Nor are they (or any one piece masts over about 7m) filament wound. A vacuum pump is $150 (compare that to the wood and metal working tools in your garage), the other vac bag stuff can be bought cheaply from your local hardware, once you know what you are doing.
I supply the laminate if we have already built a similar mast. Otherwise, engineering is $700.

As with everything new, start with small samples. These can be fibreglass with whatever resin you have. Once you have bagged your first piece, you will wonder why all laminating is not done under pressure. There is a similar epiphany after the first successful infusion. If you want to have a go with either, let me know and I will tell you what you need to set it up.

They are prebent and were hard work to build. They were also an experiment and a first attempt, so don't be too hard on them. The current Schionning biplane boat owners are buying their masts from us.

These are pretty simple as they are flat or single curvature panels bonded together, but would be even simpler if they were box section. As they remove the need for travellers and vangs, they are worth the effort.

They are round. Using my method, non rounds are no more work and multiple tapers only a little more.

I have made more mistakes than most since my first carbon mast 20+ years ago. However, carbon is so much stiffer and stronger for it's weight than anything else, vacuuming is such an efficient way of compacting it and adding more laminate is so easy that very few (but not all, see 7th picture down at http://harryproa.com/Articles/articleu.htm ;-)) of them have been throwaways or broken in use. The method used in the plans I sell is tried and tested and simple. If you think it is anything other than simple and easy, I will refund the plans money.

Paul B,
Thanks for your honesty about your rigging experience. What was the insurance company that did not care about the age of the rigging? Any chance you could answer the other questions about your boat and rig from post #53?

Groper,
Great to hear from someone who is actually doing it.
Thread drift:
I have designed a couple of cats but most enquirers want the same stuff that everyone else has so I just send them to one of the advanced cat designers. However, if you want a cat that is different and/or with cheap/easy to build hulls or rig, let me know. The ideas stage is the fun bit. Happy to sketch and discuss this for nothing if you send me your list of wants and ideas.

rob

 

Rob:

Thank you for your detailed and objective response. Between your response and Grouper's I'm certainly feeling much more confident about trying this type of technique.

First, it is Steve Clark (without the "e') - I made the same mistake in correspondence with Steve and he finally corrected me!

You don't know how much I appreciate hearing first hand numbers and times developed through experience, rather than some blow hard quoting Internet posts third party.

I thought so but wasn't willing to bet my reputation on it. With that much bend on a 15-20% reef I kind of doubted the bend displayed matched the apparent halyard tension and the lack of stress distortion on the sleeved luff. This was a surprising picture for Schionning to put on on their site, as the sloppy reefing and failure to tension the sail foot appears to have let a lot of draft into the lower part of the sails - causing a lot of the flow problems.

They do look like they'd be a real challenge to build - especially because they will be visibly compared to another example with the same sail a few feet away. On single masts, consistency isn't a visible problem.

I can see the potential simplicity when visualising your build methods.

Experience and being able to start from a point where it is not necessary to duplicate errors and failures made by other people is one of the most critical components necessary for progress - in any field.

My point regarding the expensive, wasteful period in which knowledge and efficiency are developed is dead on - if everyone has to start from ground zero and go through the same level of experimentation and trial and error. You've obviously earned a lot of scar tissue that may prevent other people from making the same errors. Thanks for sharing.

Ditto. Paul B. has demonstrated encyclopaedic knowledge over the years here - and earned a lot of credibility with me for his blunt presentation and ability to cut through the bulls#!t. I'd rather get nastily gored for being intellectually sloppy by someone like Paul B than much of the third party cheerleading and Suzy Sunshine nonsense demanded here. I think the "rep points" system here is completely out of phase with reality and needs to be separated from "personality, popularity and seniority points".

Thanks again for your patient reply and willingness to keep going with the conversation in the face of contention and doubt. Truly professional.

--
CutOnce

 

Just a quick report regarding gravity storms.

The Wyliecat 30 UNO experienced a localized gravity storm during the Ditch Run a couple of weeks ago.

Seems maybe the stayless rigs that just need to be stepped and then last forever might be a myth after all...

 

Got something to say ????

'Paul B' - Please read title - "Got something to say" - if so please tell us - so we can try to keep pace with your elevation information services.

If not - & it's just another - I'm smarter than - better than - know more than - all the rest of you - continuing attitude of yours - then just go away & shut-up & let someone else with a tinny bit of comphrension about communtication skills - have the floor - please. james

 

I think PaulB has a point. Everything wears out and will eventually break. With a conventional stayed alloy rig you can inspect the pieces for corrosion or wear. Replace the wire at intervals suggested and with proper maintenance it's likely to give good service. With a CF free standing rig the big load and the one that is going to make it fall down is at the bearing at the deck. How do you inspect it? The CF and laminate is deteriorating all the time. How do you tell when it's had enough?

 

But it doesn't work like that. Stayed rigs do break sometimes regardless of the maintenance. It's a matter of engineering practices how much safety factor and allowance for fatique is given. Aluminium and ss are among the worst materials to inspect in this regard..
BR Teddy

ps. And Silver made a good point. It's been up many times before..

 

OOPS. Sorry Steve.

He (and Richard) would be more credible if they would answer questions when asked. see examples in my last post.

PaulB,
Thanks for the Uno information. Much appreciated. I got the following from Ted van Duesen, who designed and built the Wylie masts.

Rob, It's nice to make your acquaintance, if only by email. It looks as though you are doing some interesting work.

I designed the WylieCat masts and the laminate. Uno was the second WC30 built 17 years ago and Tom was exploring how far he could push the depowering concept in order to achieve both very good up and down wind performance without having to hoist and strike off wind sails. Composite Engineering, the company I founded and manage made the bare tube for the mast, but WylieCats did the outfitting and finishing. The masts were designed for use as a cat rig only and much of the design challenge was making the masts as small and light as Tom wanted, but keeping them stiff enough so sails could be made that would work efficiently through a wide range of wind speeds.

As you know, it is really important to reinforce a composite mast where there are holes to avoid stress concentrations that lead to failure. It is no different for aluminum spars except for the ductility of the metal. Here a load could exceed the yield stress and the metal locally yield. Only after a number of load cycles would the metal fatigue and crack. We are seeing this happen with quite of the few of the older Nonsuch aluminum masts. Unfortunately, it was hard to convince the builder that reinforcing should be done to carbon masts, and as they were working out the layout, they did not know where the fittings and halyard exits should go until they had built a few boats.

Tom sent me a short fax showing what happened, which I will share with you. They were sailing on a broad reach at over 12 kts in over 30 kts true wind speed with a large spinnaker up in addition to the main.The boat has been sailed a lot throughout her life in the windy Bay area. The pole was 3.7 m long and attached to a ring on a stainless steel band 1.25 m up the mast form the deck. Eight 1/4" screws were tapped into the mast to hold the collar in place. The foreguy put considerable compression on the pole and the mast broke cleanly at the collar. I do not believe there was any reinforcing at the collar.

I guess that I have to categorize this adventure as destructive testing since the spinnaker was not considered in the design and the rig was designed for minimum weight as a catboat. Still it is tempting to see just how fast you can go. It is very likely that there was enough factor of safety in the mast that everything would have been fine if there had been a little reinforcing added at the collar and halyard exit. I doubt whether am aluminum mast would have stood up anywhere as well. Still it's sad to loose a rig. We really prefer to finish the spars we build just to be sure that all the details are done properly. It's a difficult challenge to work in a team on a totally new development project and insist on following all the details when you are on the steep part of the learning curve without slowing all the development down. In retrospect, it's nice to see a prototype for a new concept stand up so well. Ted Van Dusen end

By the way, apparently Uno has been a very successful racer, particularly shorthanded, which is the answer to the question you were asked in post #35.

Sean9c,
Everything does wear out, but if a carbon mast is only subjected to the loads it is designed for (ie no banging into bridges, dropping it on the dock or highly stressed fittings added without reinforcement) it should last longer than the boat it is on, assuming both were designed for the same loads. Why? Because the fatigue properties of correctly built carbon are way better than those of any other boat building material. See p 13 of http://www.westsystem.com/ss/assets/HowTo-Publications/GougeonBook 061205.pdf. This is one of the reasons that carbon has taken over from alloy in the incredibly conservative passenger plane business.
Where the mast is an add on to the boat, we allow a hefty safety margin for long term fatigue.
An added safety factor is that boat masts that are stiff enough will invariably be way too strong. So the mast is likely to bend a huge amount before it breaks. Generally speaking, this load will be less than the righting moment of the boat so the mast should stay up.

How can you test it? There are numerous non destructive test methods which will pick up voids, flaws and damage. They mostly use heat and ultra sound, but there are many new techniques in the works. Some of them can be used before the mast leaves the factory, others are portable so can be used on the boat. Maltese Falcon has fibre optics in the masts which relay loads and other information. This will eventually trickle down.

The worried owner can do the simple static bend tests we do in the factory. If the results are the same, there is nothing to worry about. Of course, any mast that is subject to impact or uv damage (lost paint) should be inspected and if necessary repaired. And no fittings should be added without consulting the engineer or manufacturer.

rob