I've read in several recent posts mention of people wanting (or dare I say lusting for) carbon superwing masts on F16's. Although I've also read these are readily available on A-cats, unless I've missed it, I have yet to see them available on any F16 (understanding that the carbon mast on the stealth is not a superwing mast).

So what's the story here - are they now available (or are they perhaps rumored or expected to soon be available)? Since the aluminum superwings are so good, what will be the benefit of a carbon mast? I would guess it might be a little lighter and maybe the stiffness could be tuned for sailor weight and/or desired mainsail luff shape, but would that be worth the extra cost? I would bet they would be less durable, both to damage and UV. Sexy, yes; practical or better I'm not sure...
Thanks for the input,
Jerry

I think it's just that no one has actually put one on an F16 as yet. The carbon A class section, in my opinion would be an excelent option, we use it on the F14 and the difference from Al' is "outstanding". It is so much lighter and the strength is "major", Nothing like the "delicate instrument" that we were told it would be before we incorporated it.

Well, the Stealth carbon mast is special in its own right, with a tapered top section and it is a breeze to right.

But you are right in the sense that we haven't seen a carbon mast in the F16 class yet with a crossection profile as used by the A-cats and the (alu) Superwing mast.





Pretty much if you lay down the money for one then you can have one. I think it is safe for me to say that we'll see a second commercially available F16 carbon mast (with A-cat cross section) being introduced in the foreseeable future. I know a certain supplier has indicated looking into it. That is all I'm allowed to say at this moment, I think.





The carbon mast would certainly be lighter, probably by some 3 to 4 kg overall not more. This is because the F16 rules has rule that limits weight reduction on the mast section. This is done to keep alu and carbon masts in the same performance ballpark and to garantee seaworthyness of the design. Having said this, I'm told by carbon mast builders that the F16 rule is pretty decent for carbon masts. They can be build lighter still but the min weight in the F16 rules is a pretty good average for a dependable mast without going overboard. The builders like this as well, it levels the playing field a little bit and gives customers protection against special (disposable) masts. It is considered a good compromise.

My personal opinion is that a carbon mast can be made to suit any crew set/crew weight/sailing style and in that sense it is attractive. The lighterweight will make the boat feel more stable and make righting singlehandedly a breeze. Having said this I expect the alu mast to be a better compromise for crews who switch between doublehanded sailing and singlehanded sailing often. It is also a very attractive option moneywise and it will hold up better to things like UV-degradation and outdoors storage. I regard the alu version to be pretty capable already and in that way I don't expect that much difference between the masts.

I always understand that a full sail can always be made flatter by bending a mast (alu rig) but that a stiff/flat rig (carbon) can never be made fuller (using only normal trim controls). In this sense I feel that an alu mast has a larger range of usage (2-up to 1-up and back).

So in summary I don't think one is per se better then another; it all dependents on your way of sailing and the configurations your are exepect to sail in the most.




But the new carbon mast are quite developped in this respect by now; indeed alu last forever, but I don't think carbon is comparable to say 10 years ago anymore.

Wouter

Hey I know I haven't been posting much lately, but you seem to have forgotten F16 altered has been using Carbon A class section mast for over a year.

It is a OZ built second hand A class mast, which I put Cedar timber cross ways up the inside covered with epoxy glue. This has made it bullet proof and brought it up to F16 min. wieght. I believe second hand A class Carbon masts are certainly a option for the individual F16 sailor, especialy as some are now considered to heavy or stiff for A's and anything other than a Fibrefoam is considered not good enough in OZ for most A sailors, meaning there are some second hand ones around. Saarbergs (European made) and Applied Composites (OZ made as used on Altered) are the non popular ones I have heard of.

There is also a modified Taipan 5.7 getting around with what looks like a A class section carbon mast on it, I think it was built in Sydney. If it is strong enough for the 5.7 it would certainly handle a F16.

Regards Gary.

Yes, agree. When speccing a carbon mast, you can work out the bend charicteristics you want and then get it built into the actual construction. A "whippy" top to allow some automatic gust response when the appropiate amount of weight is out on the wire so allowing you to have less work to do when it's gusty etc.

But it will mean that people need to understand this when buying a 2nd hand boat with a carbon stick - if it was sailed by fat bloke(s) then the mast will be too stiff for think bloke(s) and visa-versa.

Thanks, guys, for your feedback. Good points all.
I had forgotten about your carbon rig, Gary, sorry!
Wouter, you got at one of the issues I was hoping someone would address, which is that I suspected that carbon rigs may have a slightly more limited range even if they can be more precisely tuned for one specific set of conditions.
But I'm not sure if that necessarily has to be true. Even though I'm under the impression that carbon overall is stiffer than aluminum in general, I would think that the overall characteristics of the aluminum mast (range) could be duplicated in carbon, but maybe the cost would negate the benefit of the lighter weight. Specifically, I'm thinking in terms of wall architecture, not only fiber thickness/direction but also reinformcents/ribbing etc analagous to what was done on the aluminum extrusion.

It's interesting that in windsurfing, where virtually all the masts are carbon, the entry level models are 50% or 75% carbon whereas the premium masts are 100%. The best racing masts are 100% prepreg. The lower carbon content masts are good, but you can feel a difference in the higher end masts, both in weight (especially for really big sails) but also in "dynamic response", ie, twisting off of the tip in gusts or when pumping for example.

My last question is: if a one were to buy a carbon mast tuned for one's weight, when sailing it vs an aluminum mast, what would one feel as the key differences; especially, how would the two rigs compare a) as wind strength increased and one needed to depower, and b) in very gusty weather?

Jerry

Jerry,
There was a time when AHPC produced two different mast sections. Cat rigged and sloop rigged superwing sections. The Cat rigged section had a thinner wall.
Now you can only buy the sloop mast and it is used in both configurations.
Now we're talking about cat rigged and sloop rigged carbon masts.
I expect you would be able to replicate the AHPC mast in a combination of carbon and glass to meet the bend characteristics of the aluminium mast and use it in both configurations. The weights would be almost the same as a full carbon mast as you would just be replacing carbon with equal weights of glass to maintain similar wall thicknesses for manual ruggedness while tuning the bend characteristics with the carbon type and orientation.
I expect with the addition of glass the mast would be more durable as it would compensate for some of the downsides of physical properties of carbon.
The Aluminium mast will always cost less than the carbon mast because of the labour component in the cost of the carbon mast.
On another point re UV protection.
When carbon masts were first being made with wet layup they were subject to UV degradation.
The move to pre-preg construction provided two significant improvements.
1)They are now built using a resin with a stronger resin matrix. The stronger resin matrix allows the layup to stand up better to compressive loading which is a prime cause of mast failure.
2)The second improvement was UV resistance. A UV inhibitor is included in the re-preg resin.
Personally I would probably store my mast out of direct sunlight but this should not be such a big issue with the UV inhibitor in the resin.

This is just the way I see things.

Regards,
Phill

Phil, the Inter 20 carbon masts are all painted white for protection. Obviously this adds weight but how much?

I was concerned when I first got my Jav 2, with it's black carbon mast, because I live in Florida and leave the mast up on the boat in my backyard (lake front) all summer. I was surprised some times on a hot day, I would touch the mast and it was not all that hot, not nearly as hot as what a black peice of metal would be in direct summer Florida sun (most black cars get up to 140 degrees F. in the direct sun)

So, how big a deal would it be to paint the carbon mast white? That would give it some scratch protection as well. You sure don't see any black carbon A cats sailing around.

Tim,
Standard resin will start to break down after 90deg Centigrade. Pre preg is heated to cure and while much of the curing can be down at 80 -100 deg C it needs a period up around 110-120 deg C to make it resistant to high tmperatures after it has been cured.

I can't tell you exactly how much weight you would add by painting a Mast. But I have painted beams once. It adds around 1kg per beam. Notice I said once.
I couldn't get over how much weight it added. Now given the prep material before the top coat adds weight and prep material will most likely not be required on the epoxy mast I'd guess you would still add close to 1kg to its weight and that is a weight increase of around 10%.

Personally I wouldn't paint it.

Regards,
Phill

Phill,
The early wet layup carbon beams and masts went soft at 70C!.. Which is in the ball park of a black beam in our sun..
On a sunny day in Perth the moth wings wilted!!..

Stewart

Stewart,
It does not surprise me the moth wings wilted in the sun when done in wet layup and left black.

I'd be interested to find out how they make the I20 masts considering they feel the need to paint them.

I'm sure the I20 mast would be lighter if left black but they offer a warrenty. On a side note, the Corsair F28 C masts are all white and most other carbon masts and hulls are white. I don't know if it's paint or gelcoat.

Tim,
Very few hulls are built from pre-preg Marstrom hulls are the exception.. The rest are usually wet layup so the UV protecion has to go on the outerside as there is no UV protection in wet layup Resin.

The protection of choice for hulls is usually gelcoat becuase of its durability.

With wet layup a competent laminator will get around a 50/50 resin fabric mix by weight. The pre preg has the resin impregnated into the fabric in a lab and is controlled to a choice of 37 or 39% of resin.
When you are looking at laying up a mast pre preg delivers UV protection, a much stronger layup due to the stronger resin matrix and it will be lighter becuase of the carefully controlled improved resin/fabric ratio.

As far as hull construction goes it is mostly wet layup. I think Nacra claimed the Infusion is the first cat built with resin infusion.
The Blade F16 by VM was built using resin infusion for nearly a year now and there is another manufacturer that I know of using resin infusion for hull production.

It is certainly my view that all production boats should go to resin infusion as this produces a better product using a cleaner process. Maybe this will be what is needed to bring the weight of main stream production hulls down as the process itself pushes quality up.

Just the way I see it.

Wouter-
Don't forget the original BIM 16 here in the US had a RIBA CF mast derived from their A cat CF mast, and that was way back in the origination days and the reason we did not "outlaw" CF at that time-

Kirt
Taipan 4.9 US159

Phill,

I am not sure about the new sections, but the Omohundro masts were made on a male mandrel, and if you chipped off the paint you were looking at a significant amount of fairing compound. The paint was primarily a quick way to dress it up.

M

Phill,
I believe the International 14s built in South Australia are prepreg.. Could be wrong...But from the looks of them they seem to be...
I would also be surprised if the Windrush International Moths aren't prepreg..
As for classes.. I believe the 18teens are all prepreg..

Apart from the oven which need to get to 120C prepreg is easier than wet layup.. Lay down, cover with core, lay down vac and cook.. The issue of not wetting out the carbon fibre isnt an issue..
Windrush uses a home made tin oven, but a ply oven would work as well.


Stewart

Stewart,

I hadn't even considered monos when making the post.

Agreed, pre preg is much easier.
It is also a lot more expensive.
From memory the pre preg plain weave carbon was 50% more expensive, the glass was around 500% more expensive while the Uni was actually cheaper. I still have SP Systems pricing around somewhere probably out of date so things may have changed.

I don't know of any cats being built from re preg carbon?
Not even aware of any A class built with pre preg.
I think there are other resons apart from cost but I won't
go into that here, happy to discuss offline.

My personal veiw is that for hull construction Infusion is the way to go when considering, cost,quality and controlling quality as well as ease of construction.

Mast construction:- pre preg is the way to go.

Just the way I see it.

Matt,
Thanks. That explains a lot.

Regards,
Phill

Phil:
Is that the whole idea behind the new Nacra Infusion? I know they redesigned the hulls, but is the name from the change in a hull laminating/layup process? What in nonengineeerspeak, is that process and the difference between those type of hulls and what is currently being produced?
Hate asking you the question, but since it came up I felt I oughta take the opportunity. Especially awkward question since the Nacra Infusion Hull shape seems a pretty close visual clone of your Blade-18 design. Just my impression.
Cary

Cary,
I should't really guess the answers to your first two questions.
Please read the following quote from the Nacra Europe web site and draw your own conclusions.
"Construction
The Nacra Infusion is the only production catamaran that is made with infusion technology. This technique makes sure that weigh distribution in manufacture produces a much stiffer hull compared to conventional methods, and stiffness of hull produces extra performance in high level racing for many more years."

Essentially instead of wetting the cloth out by hand where both resin/fabric mix and quantity of air trapped in the layup depends on the skill of the laminator. The hull or component is layed up dry. A light weight fabric is included in the layup to act as a transport medium and a vacuum is applied.

The resin is mixed in a container and tubes from the container enter the layup at preset distances. Once the vacuum is confirmed without leaks the taps in the tubes are openned and the resin is drawn from the container into the layup. You can see the resin migrate through the laup. As each section completes saturation the taps are turned off and the vacuum can be held until cure.
There are many advantages other than the quality of the end product. Not having to touch the resin means a lot of the human error component is taken out of the equation and with that goes things like wastage. A by product is a process that is also better for the environment with reduces gas emissions.

Hope that helps.

Regards,
Phill