It would be possible, though not ideal, to use a stepped pole. There are masts around that have been assembled from two tubes with quite a difference in diameters, and with a conical adaptor to allow the sail to slide over the join.

Nedal is a big enterprise, and the extruder in the Netherlands, and supplies customers across the whole of Scandinavia and Europe. I would be very surprised if there were another one in such a small country

They seem to be available in 4 and 5 mm wall thicknesses in various lengths, although sold only in 6060.

Jami Jokinen wrote:Points taken, thanks. 

I'll wait for the info about the alloy type of the flagpole and go on from there.

If the tube is 145mm and I will add 6-10mm of glass, how big should I make the hole at the partners (of mast collar, should I have one welded) - to leave suitable amount of space for the wedges?

Jami,

That depends on how accurate you are when lining up the mast step and partners. On earlier boats (Malena, Johanna) I made room for quite wide (3cm?) wedges to make sure I could adjust the mast rake to set right, even with a little error in the mast step.

On Ingeborg I made a (temporarily) movable mast step, then test-stepped the mast and moved the step about 1-2 cm forward to get the mast right. Then the step was screwed and epoxied permanently in place before re-stepping the mast This method lets me have neater partners with only 20mm wedges. I take care to make the wedges with fine angles and with a lip on top to keep them from ever dropping through.

Arne

Jami,

What causes stress in an un-stayed mast.

The two biggest factors, which stress a mast, are sail pressure and the pitching of the boat.

To minimise the last factor, I have made a habit of making moderately short masts, and then pile on some sail on it.  The original reason for this was that the quite stout and heavy spruce masts I used, would otherwise add too much to the hobby-horsing of the boat (increase ‘pitch radius’). With aluminium, I am more concerned about the whipping of the mast and eventual fatigue, as David mentions, so I still keep the masts as low as I can. I am less afraid of sail area, as the stability of the boat will put limits on how much sail one can carry in a rising wind. The HM-style sailplan lets one set the biggest and tallest sail on a given mast length.

The rigs I have drawn for your Gallion 22, at least the smallest rig, must be said to have a moderately short mast, which will not add nearly as much stress on itself in a seaway, compared to some tall JR masts I have seen.

I am not sure if the lower section of your mast will see most stress and need an inner section added. Remember, the pole is tapered. I suggest you try it as it is (with the added GRP around the partners) in moderate and rising winds and then observe it (go to the mast and sight up along it). It may well be that you will spot a nice and even  -  and hopefully moderate  -  bend up along the pole. This is a fine thing with free-standing masts: It gives a quite accurate feedback about how much and where it is stressed. It will scare you long before it breaks.

Arne

However, I also have to balance between this and the availability/cost of the materials - as is the situation to everyone else, I suppose.

Regarding the lifespan of the mast, five years seems too short, ten years would be a lot nicer.

EDIT: The wall thickness of the flagpole is 2,5mm and not 2,8 as I thought. I don't know how much difference this makes. I have contacted the seller and demanded exact info about the alloy type.