Black Diamond fins are carbon sandwich constructions that are individually handmade according to the customer`s wishes. Size, flex, twist and rake angle can be customized. Tuttle, Deep Tuttle and Power Box are available.
Black Diamonds are moulded fins. The carbon fibres are of high quality, no prepregs, for some designs high modular carbon is used.
The epoxy resin applied in our product is of top quality and recommended by the German Bureau for Aeronautics. It withstands continuous vibrations and guarantees a long period of stable performance of the fin.
Finishing and workmanship are impeccable. For continuous improvement and perfection top windsurfers have been offering their feedback.
Excellent sailors are giving their feedback for achieving best results in fin production.
We do not intend mass production.
Our goal is to satisfy the individual sailor and to improve his racing results.
The current TESTING TEAM:
Michael Rossmeier: Freestyle
Thomas Fauster, Andreas Tezzele: Slalom
Jurjen van der Noord: Speed
DETAILS ON CONSTRUCTION AND MATERIALS
Black Diamond fins are moulded fins and hand-laminated sandwich constructions.
We only use epoxy resin of top quality recommended by the German Bureau for Aeronautics. It is approved to be used in combination with glass, carbon and aramid fabrics for the production of manned aircrafts. The resin is outstanding for resisting permanent vibrations, excellent adhesion to enforcement fabrics and for minimum shrinkage. Resins of minor quality do not withstand the vibrations of longer duration, endurance is drastically reduced and therefore the fins can break easily.
All the carbon fabrics materials used are of aircraft quality. They are able to withstand permanent vibrations, they have a low volumetric weight and high tensile strength for stiff composite constructions. For fins with a very thin section like for type S1 high modular carbon fabrics are perfect to withstand the extreme stress.
A sandwich construction is a structural panel consisting of two relatively thin, dense, high strength sheets of structural material with their faces bonded to and separated by a core. In the case of Black Diamonds, the structural material is made of carbon laminate and the core material is epoxy resin. The carbon layers have to cope with the tensile and pressure forces. The core serves as a spacer, maintains the fin profile and has to cope with the shearing forces.
For the construction of the carbon laminate, the carbon inlays are put into the female mould in a predefined angle. Then they are soaked with the resin-hardener solution and de-aerated. All layers are laminated “wet-in-wet”. The fibres consist of microscopically thin and parallel single filaments. This parallel position makes it possible to meet all the lines of force in the laminate. In this way, the construction can be adapted to the stress which leads to less weight and higher durability. In addition the flexibility, in terms of twist and flex, can be manipulated.
The construction details of each single Black Diamond fin are documented for future use. If later on the same fin is ordered or the same fin with a different flexibility, rake angle, nose radius or length this can be done easily.
DAMAGES AND REPAIR
Fin damages mostly occur on the leading edge or on the tip. These damages always cause a small lag of speed potential, the lift of the fin is worsened especially with a wider angle of attack, planing and acceleration are not at their best any more. Spin out is to be expected more frequently.
The leading edge is responsible for the development of the flow which is crucial for the fin function. Therefore, all damages on this part of the fin should be repaired properly. You may either use epoxy filler or pure epoxy resin.
Damages to the fin tip can be ground away and the fibres can be sealed with epoxy resin or car varnish. In case of a heavy damage, you even may cut off the tip parallel to the base without much of a disadvantage.
If the trailing edge is damaged, repair is mostly a bit more difficult because of its thin section. All projecting parts should be ground away and – if possible – the edge should be square.
BUYING A FIN
If you know which type and size of fin you want to buy and if you have made up your mind for either a moulded fin or G10, there are still a few details that you should think about.
Check the leading edge of the fin with your fingertip, there must not be the slightest damage. Even if the edge is rather sharp there must be some nose radius to be felt or seen. A completely sharp edge has to be taken away with fine grinding paper. Let them do it in the shop and then check again.
There must not be any asymmetries in the fin profile, no dents or other irregularities. Try to get some information about the relative thickness of the fin and the section profile, these are essential features.
The trailing edge should neither be razor-sharp nor rounded. The fin should end with a clean square edge.
If you are not an expert it might be difficult for you to judge the flexibility in terms of the flex and twist. If you don`t trust the shop ask an experienced friend.
The position of the fin blade in the base has to be symmetric, the chord of the fin section has to correspond with the centreline of the board.
The base has to fit tightly into the box, the upper edge of the base should be on the same level as the underside of the board. Therefore take your board along for buying a fin. After you have fixed the fin in the box try to bend the blade sideways, the base should not move.
Quite often it is necessary to adapt the fin base to the box of the board as the different producers are using boxes which deviate slightly from each other. Fitting in fins with Tuttle or Deep Tuttle base is a delicate job as both sides of the base are parallel to each other. Never use force on the screws to pull the fin into the socket. Grinding paper, adhesive tape and lots of patience might be necessary to get a good result.