Interesting info, protruded for battens wrapped for masts

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choco said..
Interesting info, protruded for battens wrapped for masts

?si=RIUVGnm2c6rnR8Zr

Roll wrapped for both.

masts aren't roll wrapped - as they're not made with woven cloth wrapped around a mandrel, rather its continuous filament winding (ie: a third method)

Some are pullwound.
Others( probably most) are roll wrapped

In the only definition i know of it, "roll wrapped" is one bit of cloth rolled. Like rolling a ciggie.
No masts made like that.
Mast manufactures is one tow, or a number of tows say 1-5cm wide, coming off a spool and wound around the mandrel

Not pultrusion, nor roll wrapping

No that's not an accurate description of roll wrapping unless I have misunderstood you.
Roll wrapping just mean you lay up the cloth on the mandrel in whatever orientation you want, doesnt have to be one piece of cloth
Mast I have here is a mix of cloth(0-90 weave 1 piece) and UD(lots at zero and less at various off axis) it was made by roll wrapping onto the mandrel. Most of the masts are made like that.

Putting aside the small ending/join areas that have a wrapped piece of carbon for re enforcement, Im not seeing any roll wrapping on any of my masts, and theyre all layed at 0 degrees/90 degrees.

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Mark _australia said..
masts aren't roll wrapped - as they're not made with woven cloth wrapped around a mandrel, rather its continuous filament winding (ie: a third method)

This is not true. Most masts ARE roll wrapped using 0 & 90deg unidirectional Pre-preg. The woven cloth is mainly cosmetic & on the outer layer only. The 0 deg & 90deg layers are interspersed at exactly the right positions in the lay-up, seams are staggered on the 90 deg layers to minimize thick spots &/or variation in stiffness. All the No Limitz(Ezzy Goya) made masts are made that way. And most if not all of the Italian(Italica), & Croatian(Proxima) factory masts are made that way. Not sure about the Chinese factory but very few masts are made using filament winding anymore & AFAIK the only high end masts not using roll wrapping, use a "Tow-preg" process where prepreg tow ribbons are wond continuously. AFAIK only the Slake masts & masts from that factory use this technology.

Gorgesailor is correct.

A mast manufacturer (Not Euro or China) I have bought from directly, specifically describes their process as 'roll wrap'.

Powerex used to use the tow winding method, but I understand they dont make masts anymore.

There are a couple of other factories that use the filament, or tow winding process to make tubes and masts, eg. for the Slake brand.

That is an excellent video.

It makes it quite clear why most masts are made with the roll wrap method. They need some radial wrap for compression strength and must be made with a tapered section so cant be pultruded. Filament winding is much more capital intensive to set up, and therefore potentially a more expensive method.

Most masts also have the un-sanded finish, showing the pressure wrap medium pattern quite clearly. The Powerex filament wound masts I own, have what appears to be a precision ground or sanded surface with a sealing finish. An older NP mast I have, that appears to be roll wrapped, also has a sanded and sealed finish. Generally, masts are less likely to be sanded finish, as the sanding can go though some of the surface fibers, thus potentially compromising strength.

A lot of battens, both rod and tube, and both carbon and glass, are pultruded. As the video explains, they are more prone to splitting, but can be very stiff for their size and weight. Some batten tubes, particularly the larger rear sections in race/slalom sails, are roll wrapped. This is done to enhance durability, and using higher percentages of carbon too optimise stiffness. The method and material used depends on the use. For instance, wave sails are more likely to use rod than tubes where weight is less of a consideration than durability, and if they use tubes, it is more likely to be roll wrapped. Race sails use a mix of rod and tubes and of different constructions in different areas of the sail.

Carbon booms may use a mix of construction methods. The curved sections, and often the whole front section are generally made in split moulds. Straight sections are usually roll wrapped, sometimes joined to a split mould curved section.

Roll Wrapped windsurfing masts have a tapered section, and therefore are made on a tapered mandrel. Some RDM masts have a parallel tube lower section and a tapered top section. Some have both tapered tops and bottoms. Most SDM masts I have seen are tapered sections top and bottom.