Well I've had an Epiphany,or Brain fart...what do you think of chainlink fence top rail as a mast,I used it on the last boat but it was only 10 feet.this one will need to be
15' 3"(3' stub and 12' 3" mast).
The toprail comes in 1-3/8 and 1-5/8,12 to 20 gauge that I have run across,it even comes in colors
Bob: Galvanized steel? How much does it weigh? That would be my first concern.
Dave
I havn't been able to find any specs on the weight,I still have my old 10' stick,I will dig it out and see if I can come up with a weight.My feelin is it will probably be heavier than would be considered optimal....
ok the piece I have is 1-3/8 od galvanized,1/16" wall thickness(16 gauge ?) and 10'6" long including the swedge ,and it is much lighter than I remember and far lighter than the 2"X 12' wood stick I made.Maybe a larger od and thicker gauge might work?
More importantly then the weight is the stiffness, which will not be favorable in a tube of that diameter. You see diameter is the key in all mast designs. There's a really good reason only a few steel masts have been made, in the last century and typically only on really big yachts. It's strength to weight ratio is good, but it's stiffness to weight ratio sucks.
Lastly building a solid wooden mast is crazy. I know what the plans say, but hollow masts aren't hard to make (box or birdsmouth) and you can have a mast that's a fraction of the weight of solid, with the same strength and stiffness, plus it's less in material costs too.
A 1.375" cold rolled steel tube (4130 alloy), with a .058" wall (standard size) will weigh .812 pounds per foot, not counting galvanizing, which will add maybe another pound. So this sounds light, but it's not big enough in diameter, given it's stiffness. Simply put, in a modest gust, it'll buckle and watch your head, 'cause it's coming down. This is one of the primary issues with steel (and aluminum to a much lesser degree) tubing.
Well if it looks to good to be true.... :'(
guess I'll stick with my wood stick,Thanks Guys.
Bob
Your back will thank you if you make a box section or birdsmouth mast, instead of gluing some 1x4's together. The boat will sail better too.
Oh I dont doubt that and I like the Birdsmouth mast.I made a short piece just too see how it works and I think I could do it,no bets on the sraight an narrow tho,but I think I will save that for another project.
The only reason I was considering alternatives is I just dont much care for the hinge setup,Which I think I complicated by making the mast octagon but it will work out.
i've re-done mine, using an octagonal style, douglas fir. i used a tabernackle, which because i'd already built the boat, winds up extending higher then i'd have liked (above the boom) but it pivots really well, snags less then the hinge system i had before. the solid mast isn't that heavy and is easy to raise by myself.
as you can see in the pictures, i need to make some adjustments to get a better sail shape, these were taken before we sailed last weekend. went out for a couple of hours and everything worked really well. i bought a new gooseneck from duckworks for $27.50, well worth it!
Looking good man.
Think I could get the diameter of the octagon portion of the mast,and the lower portion too for that matter,give me something to chew on
Is your mainsail and gaff able to go all the way down past the pivot point ?
Thanks,Bob.
the lower "stump" is 2.5" x 2.75" the mast is
2.5" square then i took 1/2" off each corner
at 45 degrees leaving 1 1/2" flat side on each
side of the mast
then i used 3/4" x2.5" stock on each side for the
tabernackle. the gaff jaws will slide over it with a
little help