Jefa rudder blades

Jefa Marine produces a wide range of standard rudder blades for boats from 26 to 60 feet length. This unique product line offers the boat builder a modern rudder blade without investing in expensive moulds. The rudders are made in our modern GRP factory and are available in six sizes depending on the boat size.
  Jefa rudder blade prices: (retail prices excl. VAT)
RUD30 GRP rudder blade 0.55 m² € 1.090
RUD34 GRP rudder blade 0.7 m² € 1.230
RUD35R GRP rudder blade 0.75 m² € 1.360
RUD40 GRP rudder blade 0.9 m² € 1.370
RUD46 GRP rudder blade 1.1 m² € 1.520
RUD55 GRP rudder blade 1.44 m² € 1.760
RUD30 rudder blade dimensions:
RUD34 rudder blade dimensions:
RUD35R rudder blade dimensions:
RUD40 rudder blade dimensions:
RUD46 rudder blade dimensions:
RUD55 rudder blade dimensions:
The manufacturing process of the rudder blades:
Jefa rudder blades are very stiff, strong and durable as they are made in a solid aluminium mould and foam filled under pressure. The production process will be explained in the below sequence.
 
All rudder moulds are produced out of a solid piece of aluminium in our machine shop. Custom moulds can be made to suit a specific rudder blade design.
 
All moulds are high gloss polished to achieve the best possible blade surface.
 
The mould is carefully cleaned and the edges are taped and covered in plastic.
 
Both mould halves are polished with mould release wax.
 
The moulds are hand painted two times with gel coat, with a ½ hour interval.
 
Sharp corners on top and bottom are filled with polyester glue, radius 10-12mm.
 
One layer of 300g powder bonded mat, with vinylester resin is added.
4 layers of 600g emulsion bonded mat, with polyester resin.
The mould is cut clean, the extra laminate at the top and front is for a better connection between the two blade halves.
The rudder stock is carefully positioned in the mould.
The rudder stock is carefully positioned in the mould.
Polyester glue is added on all contact places.
The rudder stock is carefully glued to the blade.
2 layers of 600g is added on each spoke for extra connection.
The edges are glued with polyester glue.
The spokes are glued to both blades and laminated to one side.
The form is filled with PU foam. This foam will dramatically expand in size and completely fill up any free space in the blade. Within 90 seconds the moulds have to be closed, otherwise this set is a loss.
Just before closing.
Finally both parts meet and are secured as the pressure runs up high due to the expansion of the foam.
A vent hole in the mould assures any air is pushed out so the foam is completely spread in the blade.
After a few hours rest, the mould parts are separated and the blade edges can be finished by hand.
 
The shaft entrance in the blade is sealed with Sicaflex 221
The finished rudder.
A destructive test clearly shows the overlap and foam filling.
The unique production process in metal moulds and high pressure foam guarantees a complete filling of the blade.
The cut of the bottom of the blade. The large overlaps are clearly visible and will ensure the blade parts will never separate.
The rudders are packet and crated for transport to the boat yard.
Rudders not transported by ourselves are individually packet in carton boxes and grouped on pallets.
Modifications to the standard rudders:
Via inserts in the mould, it's possible to modify the rudder blade shape. Inserts can be made for the bottom and the top of the blade.
 
RUD30 rudder blade with a modification in the bottom and in the top.
 
The complete finished RUD30 blade with modifications.
 
Detail of the modified bottom of the blade.
 
RUD30 rudder blade with a modification in the top for a production boat builder.
 
The aluminium insert in the RUD30 mould.
 
The ready rudder blade RUD30 with special top.
 
Detail of the special top side.
Jefa rudder blade CAD data:
Using below link, you will transferred to our document server ftp.jefa.com where you can find 2D AutoCAD drawings and 3D IGES files of our rudder blades. Please don't hesitate to contact the Jefa commercial team for any specific inquiries.
Rudder blades CAD library.
(when you can't open our ftp server, your browser doesn't support anonymous ftp access (mostly due to a proxy server), please contact us so we can mail you the library).