Matching Mast Sections

[phillip]

Good Morning: I'm having problems matching mast sections for a Roberts 28 ketch. I've looked at Skene's (elem.of yach. design), but just don't quite get it. Any source information would be greatly appreciated.

Thank's Phil

[gonzo]

Is this new construction or a re-rig?

[phillip]

Thank's Gonzo: This is new construction. I've been struggling with this for a while and not making any progress. I don't want to start plating until I have a plan for the masts.
I spent a lot of time tooling up and lining up material and I feel I'm ready to go. Just one more piece to the puzzle.

Thank's for your consideration.

Phil

[gonzo]

Does it mean that the plans by Bruce Roberts don't have rigging specifications?

[phillip]

The plans are complete with rigging spec. Folio sheets also provide lots of other goodies. The selection of spars is left to the builder. A choice of standard alloy sections proportional to boat lenght is shown. There are also plans for wooden masts that are built from solid beams. So..... If your building your mast from wood... do you match the wall thickness on the solid hollowed beam? Do you add a percentage because your mast has no solid sections? If your matching alloy sections... Is there a length to wall thickness ratio? If your looking at a rectangular mast, but your building a round one... Do you average the outside dimensions to come up with a diameter?

Thanks Phil

[cyclops]

Phillip. Post this thread in the wooden boat repair section. There are a group of mast people talking about "birdsmouth masts revisited . They have the experence to help you. See you there.