birdsmouth mast help needed

[Frank Hagan]

Scott, you're a builder after my own heart!  That pretty much sums up my efforts whenever I'm doing something new.  My second mast was much easier.

Epoxy is very strong, and pretty forgiving, and you have to think of all that surface area you have along those long V-s cut in the staves.  I think you'll be OK. 

[dale]

Scott,

I haven't even decided which boat I'm going to build but I'm ready to build the mast!  Can't wait to try one of these birdmouth jobs.  I built my last mast hollow box style.  I'm sure yours will be fine.

[ScottWidmier]

Last night, about 5 hours after glueing the mast up, I went down to the basement to check on the mast.  I was plesantly surprised to find a lot of epoxy drips on the form under the mast and even some epoxy that had squeezed out of the upper joints.  Not only that, but the epoxy was hard, not tacky, which is one advantage of resorting to the fast hardener.  So, dying of curiosity, I unwrapped the shock cord, plastic coated wire, and cut the string (impatiently) to see if I could pry the halves apart (crucial).  After a little bit of fussing, mainly caused by the adhesive on the painters tape, I was able to get the halves apart and a glorious sight met my eyes, epoxy had also been squeezed out of the joints on the inside all of which alleviated my fear of starved joints.  So, I am now a lot more confident that I have a mast I can use!  ;D  ;D  ;D 

I did differ a bit in method in that my mast doesn't exactly split in half.  I have three staves on the part that lifts up and the other five on the part that stays in the form.  This gives me a more complete cross-section to fit my plugs into though I do have everything strapped back together (dry) out of concern for possible warping of the three stave cap.  The need to work is getting in the way of my mast-building!

A couple of observations for those thinking of a birdsmouth mast (probably have more later).

1)  Building a birdsmouth mast isn't beyond anyones skills (if I can do it you can do it).  Just be aware of first time anxiety.

2) Making a form out of a long 2x and plywood with half-moon or, even better, half-octagon shape cutouts is highly recommended.  Makes putting the mast together a snap and helps hold the mast nice and snug leaving space under to pass whatever you are using for clamping pressure. 

3) Lining up the staves next to eachother birds-mouth cutout up makes spreading the epoxy easy and fast.  I needed 12 pumps of resin on my mast.

4)  Don't worry about the staves having a bit of warping as putting the mast together will take care of this.

5)  Innertube, rubber medical tubing, or in my case shock cord provides an easy way to get clamping pressure on the mast without having to bother with fancy knots or keeping steady tension when wrapping.  Several short lengths work better than trying to wrap one piece down the length of the mast.

I did notice that I will be plaining off almost a quarter of the flat corners on the birsdmouth mast which really does point to more staves resulting in a stronger mast.  I think the main advantage would be the ability to use thinner staves resulting in weight savings.  Basically removing unneeded or uneven thickness in the walls of the mast.  The builder must judge if the weight savings is worth the added effort though.

The mast that is currently on my boat made from 2 layers of 2x and rounded has a pronouced warp of a little over an inch so I can't wait to get this new mast on.  I also will be weighing both masts to see the weight savings and will post the results here.

[ScottWidmier]

Dale, you know you are going to build one of those Welsford beauties.  What is holding you back from admitting it?    They have the capacity, stability, and length you are looking for plus they just look so good!

[dale]

Scott,

Perhaps.  Here are my leading contenders at the moment (not necessarily in order of priority):

1)  Acorn skiff [Oughtred]

She is 11'9" with a beam of 3'11.5".  Designed primarily as a pulling boat but can sail.  I've ordered WB issue 56 which has a review of the boat.  I would love the wineglass transom.

2)  Catspaw [Herreshoff/White]

She is 12'8" with a beam of 4'5.625".  Should be a bit more stable than above.  Transom not quite as shapely as above.

3)  Christmas wherry [simpson]

She is designed to sail and is buildable from 14-18' with a 4'10" beam.  Again, nice salty look with handsome wineglass transom.

4)  Core Sound 15 [b&B]

15' with 5'5" beam.  Totally different boat but supposed to be a blast to sail.

5) C12 [bateau]

11'11" with 5'3" beam.  Your mods are beautiful.

6) Navigator [Welsford]

14'9" with 5'10" beam.  Quite a lot of boat in less than 15'. 

I'm actually leaning towards the Acorn skiff.  I'm waiting on the review.  Not quite ready to start anything though.  Planning a sailing trip to FL in Oct.

[ScottWidmier]

All of those are beautiful boats and you need to pick one what you are excited about in order to keep your motivation up through all of the steps.  Personally, I want to build a lapstrake design one of these days since it screams WOODENBOAT when on the water.  Most of my mods on the C12 are designed to make it look more like a homebuilt rather than a clorox bottle. 

The Acorn is definitely a beautiful boat but I am not quite sure it satisfies all of the needs you stated in your earlier post.  The beam to length ratio certainly would make her a dream to row but very tender.  A boat like this is a great one-person boat but two people would have to be very coordinated and move often when sailing.  I know one gentleman who built a beautiful pooduck skiff which is 12'10" long by 4'6" beam.  The round shape to the hull made her tender requiring a lot of moving around when sailing and a very tiring boat to sail long-distance in.  He would rarely sail two in the boat and you had to be ready to get wet.  The Acorn, the Catspaw, and the Christmas Werry with the shape of their hull would probably all be too tender for your wife to enjoy sailing with you on.

  Pooduck (http://www.woodenboatstore.com/prodinfo.asp?number=400%2D102).

The final three boats on your list all have hulls with harder chines so not strictly round.  Both the C12 and the Core Sound have a V bottom which has more initial stability than the first three boats on your list making them a lot more comfortable for two.  I have had my whole family, 2 adults and 2 kids, on the c12 comfortably thanks to both the beam and hull shape combination.  Of these two boats, I would probably go for the Core Sound 15 given that it is more boat (longer) and you can always add the trim I put on the C12 to the CS15.  Besides, the extra 3' isn't any harder to handle on and of a trailer.

Welsford's Navigator is a flat bottomed multi-chine hull so a lot more stable than a round-bottomed hull even though it has that beautiful lapstrake look.  Of course, you get that look with a lot less strakes and no need for ribs like the first three boats on your list so much easier to build.  My bias is for the Navigator because it has the look that screams WOODENBOAT but is simpler to build and has good stability for a comfortable sail.  I would change the coaming to be a curve rather than a point and make a platform up front with storage underneith.

Have fun in Florida in October.  Any interest in going to the Glen-L gathering in Alabama the last weekend in October?  Several folks like myself are going to crash the party...well, basically any homebuilt is welcome by the coordinators.

[ScottWidmier]

Dale, just had another thought when on the way to work.  The advantage of those first three boats is that they are easy to propel and can be cartopped or campertoped if necessary.  An advantage if you want both your Mac and a more substantial dingy along than that beautiful one you already built.  Problem is that most cartoppable boats only take two in a pinch with the notable exception of sailing canoes.  They can take two because of the configuration of the passenger where both passengers sit in the bottom of the hull facing forward in actual seats using a push-pull tiller to steer.  I had a mouseboat and now my 12' dory that I made to this configuration and they are perhaps even more comfortable, with the padded seat with back support, than my MacGregor.  The 12' dory I built is probably only 36" wide but two people can sail very comfortably in her only having to lean their upper bodies a bit to adjust to wind conditions.  Getting in and out is a bit more interesting though and having her configured for rowing makes for a bit of a challenge when you have to swap directions you are sitting.

Anyway, there are several excellent two person sailing canoe designs out there including some great looking lapstrake boats.

Besides, you can get the MacGregor plans from Oughtred and have two macgregors  ;D

http://www.woodenboatstore.com/prodinfo.asp?number=400-080

http://www.woodenboatstore.com/prodinfo.asp?number=400-020

http://books.google.com/books?id=cmQbSMxnH2oC&pg=PA105&lpg=PA105&dq=piccolo+sailing+canoe&source=web&ots=34EZFQjtZY&sig=rfzt3u4HT3AUTT1N9FJkjVjmO4g#PPA105,M1 (I have this book btw)

[dale]

Good thoughts Scott.  Oh, don't we wish one size fits all.  As I see it, I need three boats - my Mac for cruising, a lightweight rowboat (maybe a canoe) for the lake when there is no wind, and a daysailer I can keep at the house.

Another possiblity for a day sailer is the Oughtred Shearwater.  Nice size for me at 11'11" x 4'11".  She's a beaut but no wineglass transom.  I'll just keep mulling it over.

Yes, I have the Glen-L gathering on my calendar.  Might be a possibility.  I might have some time on 9/15 as well if you wanted to hook up - though I may be getting the Mac ready for the trip.

BTW:  I emailed you.  I was curious about what kind of plywood you use in your boats.  Okoume is pretty scarce around here from what I can tell.  Spruce in Peach Tree City has 1/4" and 5/32" .  The 1/4" is only $20 a sheet.  Does that sound right to you?  Seems low from other prices I have seen on the net.

[ScottWidmier]

I will look for your email.  On the Stevenson Pocket Cruiser I used BC plywood and it was still going strong when I sold the boat 5 years after I built it.  I have built a couple of small boats from 1/4 inch luan including the 12' dory it is inexpensive and a very lightweight plywood which fit my needs.  For the C12 I bought some plywood labled marine which had more plys than normal and no voids.  However, it had a fir facing so I glassed the interior and exterior to keep it from checking.  I will probably continue to use luan for small boats but, for my next major project I will probably order some okume or other marine plywood.  My time is worth it especially now that I am putting so much more effort on the finish of the boat.

Incidentally, I just finished planing the birdsmouth mast round using a spokeshave and block plane.  Good exercise, quiet, and surprisingly quick.  I do have some gaps on the outside of the mast but none really large.  Plan on filling them with thickened epoxy.  I put the mast between two sawhorses and sat on it and was surprised by how much stiffer this mast is than the solid one.  The solid one is 2 3/4" in diameter and the birdsmouth is 3". 

[Dave R1]

Take a look at this from Walter Simmons, too.

Rhodes Wherry. 10' 6"

Oh, and the grey and red Christmas Wherry is from Walter Simmons not Simpson.

[PAR]

Back to the topic of stave count with "symmetrical mouths", you can use an asymmetrical layout for the mouth and save a bunch of material and rounding. I've been using this method for many years. The mouth is offset toward the inside of the mast and has a minimal amount of material removed in the rounding process. This also permits thinner stick wall thickness, as you're not removing much in smoothing. I've built 12% wall thickness poles using this method.

On the left is the way most do birdsmouth staves, on the right is the way I do it. This produces a true hexagon which is easier to plane down to round, or in the case of the inboard end of sprits or the bottom of masts, the hexagon can be remain and fair into round, producing a classic touch. They have the same inside and outside dimensions, plus the same thickness staves.

[ScottWidmier]

Wish I had seen this earlier its Brilliant!

[Norman Colter]

That is how Graham has them drawn on my P22 spar plans too. Masts are on my schedule for this winter. What another timely thread. 

Norm