Quick Mast and Spars From PVCBy Paul Herting #596 "Huey" (2ar)
I finally made a sail for my PDR, hereís a couple of pictures. My daughter and I are squinting because the sun was in the late afternoon sky.
When I cut my Lateen, I cut a slight negative roach into the leech of the sail. I did this because in the past I've made sails where the leech flaps a lot. The effect of the negative roach seemed to cause the sail to curl slightly to windward. To me it looks like when an airliner engages the landing flaps. The idea being that the wing has added curve and develops more lift at slow speed. Maybe it has the same effect on the sail. I don't know all of the physics, but it has something to do with the air delamination being delayed on the low pressure side and the hook effect creating more pressure on the high pressure side. Anyway, the effect would mean more lift when sailing close hauled.
To get out sailing on the water before it gets too cold, I quickly made a mast from 2" PVC pipe with a stair rail rammed in it as a stiffener.
This picture shows the excessive mast bend that this PVC mast has, and this was only a moderate puff of wind. I was surprised because most duckers use a 2 X 4 which starts off as only 1-1/2" inches thick. My stair rail was easily that thick and then with the PVC it should have been stiffer. But I can see that the standard simple 2x4 mast has stiffeners on the sides of the bottom, so those masts are 2-1/2" thick.
Anyway, I donít have enough season (water temp is already down to the mid 40ís) to have time to build a wooden mast. So yesterday, to quickly replace the PVC mast, I picked up a 2" aluminum pipe, cut to 12 ft. which I have primed and painted white. It cost $42 which I don't think is outrageous Ė way cheaper than getting an aluminum boat mast. Iíll just drill through the top and put in an eyebolt and pulley. If you figure all the labor into making a nice wooden hollow mast, the price of the aluminum pipe looks more reasonable and it weighs about the same as the PVC/stair rail combination. In terms of stiffness, there is no comparison.