Tapered Spars?

Good question… and another post prompted by a comment. Thanks, Ed.

The Pathfinder plans specify extruded aluminum for spars so there is no taper. But John Welsford states in the plans that wooden spars will work/are acceptable if the wooden spars are 5% larger in diameter than the aluminum spars specified in the plans.

When John drew up a balance lug yawl sail plan for me, he specified a 19'10" wooden main mast with a diameter of 80mm. The mast tapers from 80mm at 5'10" from the foot of the mast to 58mm at the top. He recommended using staves of at least 16mm if using the birdsmouth construction method.

This link provides a lot of information and calculators re birdsmouth construction. About half way down the page is a paragraph and illustration dealing with tapering.

If I am reading that information/illustration correctly, the taper can be cut after the V-notch and before assembly. My thought is to set up a jig and use a flush cut trim bit in the router to cut the taper. I suspect I will experiment with a test sample before dealing with 20+ feet of CVG Douglas fir…

The mizzen mast for the balance lug yawl plan is "as per (original) yawl rig" - in other words, extruded aluminum. I plan to build a wooden mizzen mast using the birdsmouth method but I haven't figured out the taper and I haven't asked John for his recommendation either (I may do that soon). The main boom and yard offer opportunities to test the milling and assembly sequences for longer spars. I already have a main boom built so I may just experiment - including tapers and, possibly an oval cross-section - with the yard.

Router Cutting the V-Notches

Joel's comment asking about how the router worked cutting the V-notch prompted this post.

I am not yet comfortable enough with a table saw to try cutting something like a V-notch in pieces as small as the staves are for the mizzen mast. Yes, I had help - more like I watched - ripping the staves.

Two years ago, in a fit of enthusiasm, I bought a MLCS multi-sided glue joint bit based on encouraging words from another boat-builder. But, once I realized how small the staves are for the size spars we use, my enthusiasm waned and I didn't do anything with the bit. So now, while building Gardens, I decided to experiment with the birds-mouth method.

Having milled the test sample staves to size (16mm x 22mm) and length (914mm), I installed the bit in a Hitachi variable-speed router mounted in a Craftsman bench-top router table with finger boards. Getting the bit height and fence adjusted took a few tries but once it was set up, the routing went very quickly and smoothly. Set on low-speed, this set-up cut each V-notch in a single pass and cut without tear-out. I imagine notching the longer staves will require more help and at least some in-feed and out-feed support. I suspect that notching hardwood might require multiple passes through the router but using fir, spruce or other softwood the single pass eliminates some handling.

Of course, having convinced myself I can make birds-mouth spars, I can see making all of the spars for Gardens using this method. And who knows, maybe, perhaps, going back to make a set of round spars for Karen Ann.

Birdsmouth It Is...

I was finally able to get to the shop to test the birdsmouth technique for building spars. Actually, it wasn't a test of the method so much as a test of my abilities. My first reaction to a new-to-me tool or technique is usually, "Oh, man, there is no way I could do that…" and I dismiss the new-to-me tool/technique without ever trying it as beyond my abilities. Then, with the passage of time (sometimes weeks, sometimes months or, in this case, years), I eventually try the tool/technique to discover that I can, in fact, use it! Such is the case with the birdsmouth technique.

I am happy to say the milling of the staves went without difficulty using a drum sander (to thickness the stock), table saw (to rip the staves to the proper width) and router table (to mill the birdsmouth V-notch).

Gluing the test sample also went without a hitch. The test 'spars' are the same diameter of the mizzen mast and I found the staves to be easy to run on the router table - one of my earlier concerns. Hose clamps worked well for these short sections and, I am sure, would work on the masts - assuming I have enough on hand.

Gluing up two 18" test samples with TiteBond II is probably not an adequate dress rehearsal for gluing up two masts (14' mizzen and 20' main) with epoxy. I think more helpers and a warmer day will make gluing up the masts a relatively painless experience. A gluing party may be in order this spring. Beer may be offered as an enticement…

Two lessons learned in this experiment: One, the birdsmouth technique is not beyond my abilities. And, more importantly, Two, most boatbuilding techniques involve a series of simple steps, which means I can learn most -if not all- of them. I just have to remember that second lesson.

A Very Worthy Endeavor

Tom Pamperin is a boatbuilder and sailor. I first "met" Tom by way of the WoodenBoat Forum, where he is a regular contributor. Tom and I attended Sail Oklahoma in October 2011 and I had the privilege of sitting at the table while Tom interviewed John Welsford. Tom and I attended Howard Rice's Small Craft Academy in Mackinaw City, MI in June 2012, where, in addition to the classroom work, lessons and exercises, we shared an enjoyable late afternoon sail from the beach back to the launch ramp.

Tom also teaches English at the high school and college levels (not necessarily at the same time…) and writes - often of small boat adventures. A number of his stories have been published in magazines and on-line. Tom is talented, generous, well-spoken and an all-around good guy.

Tom is now writing - perhaps it is already finished - Jagular Goes Everywhere, (mis)Adventures in a $300 Sailboat. Having researched the publishing options available, he has decided to self-publish his book which is, to me, another great adventure for him. Here is a link to his KickStarter fundraising effort. KickStarter Campaign For Jagular

Take a look and, if you are so inclined, help him get the book published by making a contribution. The KickStarter fundraiser will close on March 12, 2014.

Mast Construction... Which Method to Use

While varnishing the spars continues at a slow and steady pace, I am planning and preparing to build the masts.

I have gone round and round over how I will build them… hollow box, solid round, hollow-box rounded or birdsmouth?

After much deliberation, I plan to test my skills on a sample birds-mouth spar section. It will be about three feet in length and will match the diameter of the mizzen mast. It that test run is successful, I will build a birds-mouth mizzen. It the test is not successful, I will probably build a solid mizzen mast and a rounded hollow main mast as specified in John's sail plan.

To get started, I'm ripping the staves tomorrow. Cutting the notches on the router table might be delayed as I am still consolidating my tools from two separate shops - and the weather may impact when all the bits and pieces for this project wind up here. Gluing the test section will follow soon after the notches are cut.

Shop Gremlins

Ever not been able to find something - a tool, fasteners, stir sticks, anything - you KNOW you just had in your hands? Yeah, me, too… far too often…

So, a couple of weeks ago, looking to begin working on the mizzen mast for Gardens, I went to the plans for the spars drawing - and couldn't find it. Okay, I'm sure (well, pretty sure) I had it in my hand not too long ago. But it wasn't with the rest of the drawings… Checked everywhere in the garage cabinets and workbench, checked the basement, checked virtually every cabinet in the house - all without luck. Checked the new (and uncompleted) workshop in the barn. Nope. Maybe it is still in the shop at Little House… nope, couldn't find it there although I did manage a bit of much needed straightening up over there looking for the drawing… Well, it has to be somewhere…

Went out to the workshop today to check what needs to be done with the floor. I moved a couple of things around and found two drawings… The gaff yawl sail-plan (which I set aside a while ago as not needed) and, yes, the spars drawing. Why didn't I find it the last two or three times I looked out there? I don't know. I'm happy to have found it but I'd love an explanation as to where that drawing has been or why I couldn't see it until today… The best explanation I've come up with is Shop Gremlins.

That's my story and I'm sticking to it.

And now I can get started on the mizzen mast!

It's a New Year!

As last year drew to a close, work on Gardens slowed to a standstill after she was moved to the Farm in October. The weather went cold and wet, then colder and snowy, then colder yet with ice… Conditions in the barn have not conducive to boat building these past couple of months.

Then the holidays arrived with family and friends here for a wonderful Thanksgiving weekend followed closely by a quieter - yet busy - Christmas. The weather - ice and snow - contributed to the quiet Christmas.

There has been some progress around here. New circuits and new lights have been installed in what will be my new shop. It probably won't be a proper work shop until next spring but I can see it taking shape. We also acquired a portable generator and had the necessary switch-box installed to keep things running around here during (highly likely) power outages resulting from winter storms. (Not really boat related but "fun" stuff nonetheless.)

As for boat building work, the spars will move to the basement for varnishing. A tiller mock-up and, eventually, laminating and shaping Gardens' tiller; and fairing and painting the foils are other winter projects I'll be working on in the basement.

It's a New Year! We're looking forward to a fun, busy and productive year!