Substituting aluminium spars on the Oz Goose sail boat

The plans for the various Goose versions show timber spars.

Some have contacted me asking about using aluminium tubing.

I do like the timber spars because they look nice.  But you can save a bit of weight on the yard by using an alloy tube.

Brad Hickman did all the work on this and with a suitably modified boat derived from the OzRacer went on to win the PDRacer worlds.  Six months after (???) there was an anonymous challenge to the legality of his boat.  So it was measured and was found to be class legal. His boat is the one in the pic.

Here are his spar dimensions

Alloy Spar option for Oz Goose
Spar Diameter ins Diameter mm Wall thickness ins Wall thickness mm Alloy
Mast 2.56 65 0.065 1.651 6061 T6
Yard 1.5 37 0.065 1.651 6061 T6
Boom 2 50 0.065 1.651 6061 T6


1/ I do think the mast will look much less nice than the timber version which has a classic taper.
2/ We do have a nice timber box boom design now.  Contact me for details or see the “files” section on the Goose Facebook group.

And just for general fun, here is Brad using the spars to motor upwind in his OzRacer derived boat using the Aluminium spars.

About Michael Storer
Designer of the Oz Goose and several other highly developed sailboat, canoe, rowboat and canoe plans since 1992 Sells plans internationally. We also make high quality sails for all small boats at extremely competitive prices in the Philippines and export internationally. See our groups on facebook.

5 thoughts on “Substituting aluminium spars on the Oz Goose sail boat

  1. I need to build a 3-part mast. Would 2 1/2 OD still be correct? I’m figuring my inner sleeves would be 2 feet each– 1 foot on each side of the split. Does that sound right? And is there any problem with using wooden yard and boom with an aluminum mast?

    Thank you.

    • Absolutely fine. One option is that the top third of the mast can be the same section as used for the sleeve. It will save a little bit if weight and the taper effect will help the appearance.


  2. Thanks very much, Mike. Re-examining this (after looking at the vendor and shipping options), I’m thinking of a 4-section. Bottom 2 sections would be 2.5 OD, upper 2 sections would be 2.25 OD, and top 15″ would be 2″ OD. All wall thicknesses would be 1/8″, not the 1/16″ mentioned above. Sleeves would be inserted 9″ into the outer tubes. Total weight for the mast would be around 25 lbs. Does that sound reasonable to you?

    • Hi Chris,

      Normally a two piece aluminium mast will be lighter than the timber equivalent. . A three piece mast starts to be somewhat heavier than a timber mast and four piece heavier still.

      I don’t know why you are planning to double the wall thickness – it will be a tank. Is there a problem getting the approx 1/8″ wall in the table above?

      if there is no real compelling reason to go four piece I would go two or three.

      After all, the yard and boom are already longer than half the mast which defines the stowage length. Looks like overkill unless you have something really specific in mind.

      Saving weight in the rig is probably four times more effective than saving weight in the hull, but both will give you noticeable differences.


  3. Thanks very much. The vendor says that the shipping has a surcharge for pieces over 58″. I’ve asked for more specifics about that surcharge, but I would guess I’ll end up with a 3-part. The vendor hasn’t responded with more specifics, yet.