PocketShip.net

I am looking to order lumber for the mast and all the other bright work on my Pocketship. Here in Iowa spruce is not to be had. The rub rail and the trim on top of the cabin are made from mahgany that we do have here . To make things easyer I'm thinking of making all the solid wood parts that will be bright finished from African Mahgany. Checked the difference in the two, Spruce weigths 28 lb. per cu. ft. and African Mahgany is 30 lb. per cu. ft. Using these numbers the mast weights 19.3 lb. in spruce and 20.7 lb. in mahgany, only 1.4 lb. more. The yard weights .3 lb. more made of mahgany. Mahgany and Spruce are both rated moderately hard and mahgany has good split resistance and spruce poor. Wondering if mahgany could be used for all the spares rub rails and floor boards in the cabin.Do any of you now a reason not to use African Mahgany?

ROGER

"Mahogany" is fine for a lot of semi-structural uses. Like all tropical woods it does not show grain from early and late wood, and it can be difficult to estimate the integrity of pieces. I have taken a 1x4 split it into stringers on the bandsaw and had each piece immediately warp until the ends nearly touched. Yet the original piece had been carefully sellected from a bin for straightness and grain (to the extent anything shows). This may have something to do with why it is northern woods like spruce and birch that dominate the aircraft field, because they can be evaluated.

Black spruce is readily available in lumberyards across america. But not in all regions. If you have it, sometimes you can find material in 2x10s that can be cut from around the pith and laminated into a decent spar. There are marine and aircraft suppliers that will ship you spruce, but it won't be cheap.

Mahogany is brittle, short-grained, and often cross-grained. No good for masts. With all of the really nice Phillipine mahogany gone, I've long since relegated mahogany to low-stress structural functions and decorations. It's good for rails, particularly on PocketShip, whose rails aren't structural.

Strangely enough, the best stuff for masts is probably all around you---in the form of house framing studs. That's mostly spruce of one variety or another. Sure, 9 out of 10 two-by-sixes are going to be gnarly and unusable. But the 10th will be mostly clear, and once ripped and scarfed it's the right combination of strength and weight for a mast. So go to a lumberyard (as distinguished from a "home center") and sort through the pile.

We had a deal with a lumberyard in Maine to sell us all of the clear 2x6's and 2x8's they came across. He charged us a little more, but it was still extremely reasonable. Half the cost of the sitka spruce we've been using lately. And the sitka is actually a little heavy.

It's just got to be free of twists and knots larger than a pencil eraser.

Thanks for the help. There is a lumber yard 50 miles away that might have something that will work. Not mutch boat lumber here in Iowa, one great reason to buy a kit. Great wind here today but a lot of the water is still on the hard side.
ROGER

There used to be a specialty lumber yard in West Liberty, IA called Hill Hardwood Supply. I got some clear VG douglas fir with very tight grain in 12" x 2 1/2" x 16' lengths there about 6 years ago. They probably have other lumber suitable for spars as well. They may still be there.

Found some Douglas fir at a wood supply house today. Real straight grained, 18feet long and clear. It was raining on and off all day and didn't want to get it wet so will have to pick it up another day. If this isn't good enough I have a old aluminum mast from a daysailer in the back yard, ''NOT THAT HARD UP YET.''
ROGER