Blade's strengths and weakness?

Seth's decided he's not ready to part with his Taipan yet. So now I'm looking at Blades as well. Anyone got observations on this boat? I got pretty universal praise for the Taipan, are you all as happy with the Blade? These boats are built really light, aren't you seeing them break some? Thanks!

dave

Dave:
All boats have their good stuff and their bad stuff. I have had issues with my boat in the past. Nothing that quick fixes cannot address the problems. Most of the problems were user error.

I did change a good majority of blocks lines and some minor things to make the boat easier to race ONE UP.

What would I change on the blade? Well if I were the dealer I would ask the buyer if they plan on racing mostly two or one up. I do believe the new blades are more inclined to two up racing. But this is no perfect world or perfect market so we must work with what we can get and only improve or make things better for each individual.

Having had mine for a year and just recently helping build two new blades. On mine I've replaced ropes, cleats etc and moved things to where I want them. I think the new blades are pretty much spot on regarding fittings. Matts done a great job evolving his product & out of the box, there's nothing I would change (except tiller extension)!

Having sailed all versions of the Blade I agree that the evolution is there. On the very last day of the Zandvoort event (second day of distance racing) I crewed for Geert on his Alter Cup boat. I can only say :"WOW, what a upwind monster". We had heard these comments form the US Alter Cup sailors and I can only concur. That sail design is just right.

I'm very happy with Taipan but I do think the Blade is overall better. The strong points of the Taipan are its 1-up performance in very light winds. Blade's are nicer in all other conditions in my opinion. The only real caveat is that big wind under spinnaker the Blade stays flat and calm for all the way up to the threshold and then falls off it. The Taipan is certainly less dive-happy, it is in fact more so but because the bows start nodding a little before meeting the actual threshold you get ample advance warning, on the boat you can power it up all the way to inches of the threshold and feel like you have still acres left. That is what get most newbies and a few experiences sailors as well. But once get the know the craft better you'll know where the push and were to hold back a little. In my opinion the Stealth has its strong point right there with the T-foils. And so we have covered all 3 strong points of each boat. The Viper and Aussie Blade are still to young to be judged on this but they are said to be a little bit more forgiving downwind in a blow as well. It certainly looked that way.

Also there is another thing that most F16 sailors do well to learn. It simply pays so much to anticipate the wind and gusts on the downwind legs. If you are a fraction to late then yes the bows goes (but still recovers all the time) be on time and you drive it deep and accellerate fast with each gust. Timing is absolutely everything here. If a guyy is walking away from you under spinnaker (like Tim I expect) then it is this that he is doing right. It will feel like you are bearing off and heading up again BEFORE the gust is there. Look for, train yourself on it and experience the results.

Wouter

Hi Dave,

I would not call the "Formula Catamarans Australia" Blade (the only one I have experience with) lightly built. It is every bit as strong as the Taipan, with it's standard Kevlar outer skin and Kevlar reinforcing of bulkheads and frames it seems bullet proof <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />. Or at least Hobie 16 proof so far, I have hade one bounce of leaving a dent but no cracking of the skin. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

Wouter, what makes the Aussie Blade different from VWM wrt downwind behavior? Are there any differences in hull shape?

Wow! Thanks you guys! This feedback is wonderful, and it seems that these are all well sorted, solid boats. I look forward to joining the club!

Dave

Speaking as a sailor who moved from a 70's Nacra to a 00's Blade I was surprised at how 'tender' the hulls are. I think I already had a dent before the boat had hit the water. After a couple of capsizes, the insides of the hulls are starting to resemble golf balls, with elbow and knee dents.
My boat isn't Kevlar. Kevlar may be something to look for.

I think the dents are a product of the lightweight construction. The hulls aren't glass core, it is foam core so it doesn't take much to dent the outer skin in. I certainly have more than a few. Not sure kevlar would makes much of a difference.
The HT that I had before had the same issue and the construction is largely the same.

My thoughts on buying a used US based VWM Blade:
1. Make sure the hulls are kevlar (almost all are). Look for dimpling, as described in earlier posts.
2. Check whether the daggerboards leak (my first low aspect boards leaked)
3. Inspect the rudders closely (the earlier types cracked at the rudder head)

That's about it. Most of these items have already been replaced on all early VWM Blades, but if you are looking for things to check - then that is it.

Later models of the VWM have already have these evolutions in place. It is an evolution and things do get better in each cycle. This is not a trend for VWM boats, but for all boats. Certain hull numbers have always been coveted because they are "stiffer" or "better built" - N5.2 2300 series boats are "the fastest" still today.

AHPC has had many more boats built from their moulds and have had a chance to perfect their product. US built VWM Blades have had many fewer boats built, but have been improving them with each cycle. The latest boats have been VERY good, IMO. The Blades are just as well built, just make sure they have been taken care of and kept up to date.

You will find lemons in every line of boat/car/golf club/etc. You just need to know what to look for.

Tom, I remember you and Terry ran into dagger board and or rudder problems. I have one of the same dagger boards and rudders and have never had to deal with delam problems. WIERD!

Also another thing that some other people were having problems with was the jib compression struts, ive raced my boat hard uni and sloop and never had issues. My boat does have the small dimples here and there, but those never slowed me down.

LOL

Hi all,

as suggested I would agree that Kevlar makes no difference when it comes to dents, the amount of denting that occurs in a Glass or Kevlar outer skin is a result of the core stiffness, as was said, solid glass boats had little trouble with this but they are to heavy and flexible for a F16 hull.

So the amount of denting is reliant on the density of the foam core on boats like Taipans and Blades and then it is still a balancing act between weight and dent resistance,along with thickness for overall stiffness. I have certainly seen some Mosquito's in OZ that dent to easily. Can not comment on those in the US, it may be worth asking the manafacturer if he has altered foam core density at all, as that is what they did with the Mossies in OZ.

I can't think of anything I would call a weakness. The cosmetic dimpling I have results from hitting things or dropping it off the trailer <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />.

Fortunately, I havent't hit any channel markers (with the hull) yet <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />.

Or those pesky anchor lines that always get in the way. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I don't like the mast rotation. It's fine if you adjust between races, but I'm unable to tweak it while racing. That's a personal mod. though.

[/quote]Or those pesky anchor lines that always get in the way. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> [/quote]

HAHAHAHAH

Yea Robi, that was an incredible sight. Sorta' like stubbing your toe on the (elevated) crack in the sidewalk and finding your face on the cement!

But more damage to the foils that dimpling your hulls ... unless you count the dimple on your forehead from smacking the water.

HAHAHAHA

the manufacturers can make the area around the "dimple" area harder.. by increasing the foam density in that area and adding a second layer of skin.. Reducing density in other areas as well as decreasing glass/kevlar/carbon in non dimple areas..
Just things that are modified as builders get more experienced with their product..

<img src="http://www.catsailor.com/forums/images/graemlins/crazy.gif" alt="" />

HAHAHAHAH

Yea Robi, that was an incredible sight. Sorta' like stubbing your toe on the (elevated) crack in the sidewalk and finding your face on the cement!

But more damage to the foils that dimpling your hulls ... unless you count the dimple on your forehead from smacking the water.

HAHAHAHA [/quote]

I take it your team lost. . . again <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />.

No actually played pretty good. Held the #2 ranked offense in the country to 23 pts ... while we scored 44. Yipppee.

Much better than the drubbing we took at So.FL last week.

Exactly right, Robi. I did not intend to imply that all boards and rudders were bad - but there were a limited few problems. It'd be a good thing to check prior to purchasing a 2004/2005/2006 Blade, imo.

I had a delamination problem with one rudder (an original carbon fibre rudder--not being produced any longer), VectorWorks replaced both rudders without question.

and from Bobcat
and from PTP
and from Tom (tshan)
So is there a consensus here? Are you saying kevlar reduces, but does not eliminate dimpling?

Are there other attributes or drawbacks of a kevlar outer skin?
For instance, added resistance to puncture wounds?
More difficult to repair?

Thanks

I am probably in the same boat as you actually. I know little about Kevlar but what has been written here. I think that it is more puncture resistant and I guess I extended that to more dent resistant.

I think Kevlars greatest virtue is puncture resistance.

Bulletproof baby!

I have an AHPC Kevlar Taipan that seems to be very strong and I have not seen any dimpling, leaking, daggerboard well issues, delamination, etc. I have no idea about the Blade.

The outer layer of a sandwich composite has to withstand tensile loads and the inner layer compression loads in case of an impact.
When we compare the different laminate materials:
Tensile strength [MPa] E-glass 2400, Kevlar 3000, Carbon 4000,
we see that carbon is the strongest material, but in case of an accident Kevlar has it's large advantage over the other materials.
Strain at break point E-Glass 4.5%, Kevlar 2%, Carbon 1.2%.
The 1.2% figure for carbon fibre indicates that though very strong it is also very brittle and will break shortly after the load stress passes yield point.

So the advantage of Kevlar as outer layer is, that it is lighter than glass, stronger in tensile strenght and not brittle.

In case of repair Kevlar will fuzz at the surface if you want to sand it, and it is hard to cut. It must be covered with glass or gel coat.

Here the source for the above mentioned with more technical background:
http://oneoceankayaks.com/Sandcore.htm
http://www.auf.asn.au/scratchbuilder/composites.html

There are only two small drawbacks with Kevlar. It's sensitive to light (UV) and absorbs a lot of humidity???
Two good reasons why not to use it in boatbuilding.

Those are not good reasons to discard Kevlar as Carbon is at least as sensitive to UV when untreated and glass is at least as hydrophile as Kevlar can ever be. Both other materials are used extensively so why not Kevlar.

Wouter

Still the reason why the aircraft industry has almost abandoned Kevlar is the problem with waterabsorbing...

Farrier will not allow Kevlar on the outer skin, not sure why, can anyone enlighten me, he also is quite open that you can use carbon on the outer skin but to get dramatic weight savings, the skins become so thin that they cannot withstand the impact loadings of crashing into things. He advocates glass and a good layer of it as it is very resillient to dings etc ?, easy to repair, cheap to manufacture and does the job, any weight savings can be saved elsewhere. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

Back to what Holger said Concured by extensive search of "kevlar" on this forum (after I asked) seems the common layering is gelcoat, glass, then kevlar.

The common theme for kevlar use is not structural strength, but improved dent resistance

How does the water come to the Kevlar strands as long as it is bedded in the epoxy matrix? Epoxy does not absorb water, like polyester or vinylester. So when the Kevlar is stored dry prior the laminating process, everything would be ok? And most builders use a gelcoat or painted surface which inhibits UV.

its the epoxy that is UV sensitive and heat sensitive... Maybe heat isn't an issue where you are.. It is here, so those in the know just paint the hulls...

dent resistance comes predominantly from the core density, particularly with the very light skins; carbon, kevlar or glass; used on our size boats. The thickness of skins on our size boats range from 0.25-0.5mm. That's why hard points are de-cored or have the core replaced by a harder core.

The Kevlar is stiffer and doesn’t dent (just be sure to leave the car/house keys at home and not in your back pocket)... <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

I'm changing from the "hook" system to the "keyhole" system for my harness. To me that is a good way to be proactive in the interest of minimizing holes in the hulls of my fragile Blade.

I found that the round 80x2mm alu beams are not so stiff as expected. I think these are the recommended ones which most homebuilders use. In choppy waves i can see and feel some vibration in the platform. Compared from memory to my former Nacra 500 it is noticeable more.
Would a replacement with 80x3mm carbon tubes for example bring effectively more stiffness?
How far does a little more flexible platform suffer in speed compared to a optimized platform with more rigid beams? Probably working on my sailing skills has more effect than new beams, but it is always nice to have optimal material for the beloved sport.

80x2 beams are in the homebuilding plans because these are universally availbable the world over while having a good ration between weight and stiffness.

Not all stiffness comes from the beams, the stiffness of the beams landings and torsional stiffness of the hulls between the beams is important as well. Basically, we need to find out first what the case of your problem is and adress that.

Going for 80x3 mm beams will give you 50% more beam stiffness but this will not translate directly into 50% stiffness increase of the whole platform because of the other factors named above.

Weight increase (for 2 beams) will be about 4 kg.

It is worth a try, but I don't expect more then 25% stifness increase.

How much does the boat flex now ?

Measuring this involved laying the platform up on its sterns (without mast etc) and seeing how far one bow needs to be lifted before the other bow is lifted clear of its support as well.

By the way the nacra 500 (and nacra 5.0) used the beams of the larger boats like the Nacra 6.0 and F18's and that makes them very stiff for the Nacra 500. Of course this comes at a cost, in the case of the Nacra 500 this cost is roughly 50 kg additional boat weight and 20% slower performance.

Stiffness of a platform is important but certainly not all important. More stiffness is mostly better in the way of feel in very choppy conditions. In the way of all-out speed I'm not sure how important is really is.

Wouter

For a exact measurement in this manner I'll wait till the season is over, and I have to take the mast down. Probably beginning of the november. So far I enjoy the last sailing days with cold feet