Mar 7, 2017
F18 Open Project: 'The Convertible' stage
Click renders images for HQ & Slideshow. Exploder F18 pics hulls by Matías Capizzano , F18 Exploder with Brewin Deckweeper sail by Alex McKinnon /F18 Aus Nats 2017 -- Since I started working with the F18 OP hull back in 2012 the parallel idea of having a low cost foiling platform was always there, I remember sending the final cad to Jakub telling him "if doesn´t do well floating, we'll make a foiler ...so go ahead full steam!". For the design I bet pretty high on the shape taking special care of the cross bow section and volume in that area. Luckily enough the F18 platform did good for new launched boat at Kiel, an Argentine stage nats won here , both events with the boat launched / assembled few days before, and Brewin also having some good mixed performances and a tight 4th for Agustín at the Worlds here in BA.
On the hull/bow shape finally it resulted to have one the greatest margin to push downwind in the breeze (this confirmed by Mischa, Brewin & local Arg rider) . The good aspect of the design is we defined the F18 Hull '2.0' as a reader and excellent F18 sailor rightly pointed out. Click pics to the left by Capizzano from BA F18 Worlds 2016 to see actual hull, same as renders above.
Still much room to play on the F18 platform as the 3 boats above have been sailed and raced with three different rigs/mast/sails combos.
In the end the great thing is that render in the main top header banner you always see when entering this website became a reality. Is not that easy to put your dreams into facts, and help from others is always key, in this case it was all Jakub Kopylowicz / Exploder efforts and investments which put the boat on the water.
F18 OP Second step : The Convertible Stage
In July 2015 an article where I wrote about the intention to built a 20k 18' foot double handed foiler, this was based on the materials to be used. After the article I received a hard complain from a builder for 'misleading' market costs & prices and how I dare promoting my own projects (?!). Now the same people are offering a +-20k 18' foot flying machine. So I was right, it was possible to build one in that price range.
Of course is not going to have F20/FP carbon masts, super light carbon hulls and FP refined equipment, these 3m wide cats are currently untouchable in terms of speed and stability (lets see how the Nacra MKII Z foils does against them ) but they are rather expensive, +34-40k.
The aim for the convertible platform is to fly for fun and not to win the AC or every long distance blue ribbon.
Following Morrelli & Melvin / Nacra concept of a convertible dagger case used first on their F16 and later on the Nacra 15 I came up with the idea of doing the same on an F18 platform. I'm not going to buy a 35-40k double handed foiler any time soon, so using the low cost F18 material platform (although some new F18s have raised to 23k + vat) was the perfect start to go fun foiling and at the same time continuing to race legally no problems in the F18 Class.
If you can race floating F18 from 5 to 30knots and go for a fly (changing boards/rudders) in the racing off season, well that would be the perfect choice for those who like to race in large fleets and foil too. That combo is present for those of use who participate in A-Class regattas, but here I mainly sail/foil the A for pure joy almost every day.
The added ingredient of the double handed foiler utilizing current A-Cat Z foil / T rudder tech, beyond sailing with a friend, is that you can achieve a more stable flight, this was first seen and reported on the Nacra MKII, and now also quite visible in the Phantom Essentiel.
I assign the added stability to the no span limitation and a more balanced rig with the addition of a jib & Spi power.
Right now the Nacra MKII & the Essentiel provide a more easy and stable flight than the latest A-Cat, and like technology used is exactly the same (with some dimension rules for the A) is clear that the gap is generted by the aspects name above.
Z Foil conf choice
Based on the incredible flight development of the A-Cats, the Z foil has become the defacto option for new foilers, aside performance you also have practicity as its main asset, Z foils can be loaded from the top, while TNZ Js need to inserted from the bottom and remain there always. Z foils are also cheaper to built than Js. Already discussed this point many times here in csn, no point of further explanation.
Convertible Case & build specs
Currently the F18 Class allows to use epoxy resin only in combination of wood cores. The problem is balsa cores are more expensive and do not have the same bend or mold fit provided by the foam cores. Thus to mantain the hull 100% legal and also keeps costs down , the idea is to use vynilester resin / foam cores (already used in the majority of series F18s) in combination with specific area reinforcements, which is needed as the loads go exponentiallly up, just look what happened to the Nacra 17s MKI, and a dagger case capable of supporting the straight F18 legal dagger and the foiling Z shape option.
This can be done in several ways and one has to look on the water level/space of a no specific case but frames defining an open box.
The idea will be adapting a special case which can support both boards and also keeping water space to the min.
This F18 convertible project is not the only one, after I wrote about it here last year and Dec 31 on providing more info (this post) now I know at least one F18 production builder who is going for it too. That is only great news, as it will bring new awareness for the Class.
It is important to note this project does not intend to change F18 rules, but only provide sailors with a boat capable to do both things, some are able to buy an F18 along a 35-40k double handed foiler, but they are few.
Thus being able to give your F18 a 'double program' use, will simply elevate the numbers of F18s sold, resulting in direct Class growth without affecting or interfering in any manner with IF18CA legal rules or racing.
--Already in April 2016 I sent a formal doc to the IF18CA which included the convertible dagger case concept to be analyzed.
This project is intended to continue racing in the F18 as is, for any other purpose it is better, simpler and easier to do a 18 dedicated 100% foiler platform.
Alternative Dedicated 100% Foiler: Phantom Essentiel
If you don´t pretend to race in the F18you have already great foiling dedicated options / no design restrictions at excellent costs like Alex's new Phantom Essentiel , seen here foiling in 7knots / wing seat equipped catsailingnews.com/2017/02/phantom-essentiel-stable-flight-in-7.html
F18 P Convertible Built
Those interested in building a set of convertible hulls get in touch, the idea is to prepare a special batch when built schedule permits, I will built one for me and have others here in Arg and abroad ready to jump in. - catsailingnews gmail com -
Also stay tuned as the other production F18 foiler from a known builder will be announced soon, although is vox populi in the F18 circuit, but I will wait for them to release the official news.