Building Core Sound 17 mark 1, #414

[Andy B]

@Don Silsbeyes, that is what I was proposing, sorry I couldn't explain it very well.

[Don Silsbe]

I’m on a long vacation right now.  When I get home after Labor Day I’ll put two triangles together* and work out just how feasible a conventional tabernacle would be on a 17 mk1.  I brought it up here to create a mini brainstorming session.  Reacher’s idea may have created a spark in AndyB’s head.  (Or not.  It doesn’t matter.) Hopefully other ideas will surface.  For the record, there is no such thing as a stupid idea.  The most obscure idea often triggers the very best one.

* Automotive engineers (even retired ones) schooled in descriptive geometry do not use T-squares.  They use two triangles instead.  And for the record, my transom drawing above was a sloppy actual sized sketch.

[Don Silsbe]

I happen to have a small drawing with me while on vacation.  According to this, there’s a half inch gap between the mizzen mast and the c/b trunk.  The tabernacle is constructed of 3/4” material.  My temptation is to shift the mizzen 1/4” to port to make it fit.  Would this be OK, or is this “touching Superman’s cape”?

 

I could shift the c/b 1/4” to starboard instead.  Would that be better or worse?

 

To B&B— Did I just violate a copyright law by posting this?  If so, I’ll remove it,  NP.

[Don Silsbe]

The alternative would be to shift the cc/b 1/4” more off the centerline.  There’d be two advantages to this.

1) It keeps the mast completely on the centerline of the boat and firmly on the keel batten/keelson.

2) The bailer can be snuggled up to the keelson and tabernacle at the appropriate location.  
Your thoughts?

[Don Silsbe]

New Subject—Cockpit Coaming

 

I’ve been reviewing photos and videos of other mark 1’s, and am leaning to a flush cockpit coaming, at least aft of the main’s cleats.  I like the clean look and feel on my bottom.  This decision is partly functional and partly aesthetic.  Focusing on the functional aspect, what am I missing?  Here is what it looks like on Alan’s Southbound.

I’m also considering using some thin Sapele for this, and steam bending the curve.  How well does Sapele respond to steam bending?

 

 

 

[Reacher]

Don, when I thought of a mizzen tabernacle for a 20.1 I wanted to keep the foot of the mast above the thwart so there wouldn’t be a big slot in the thwart to allow for the swing. 
 

One idea was to brace the underside of the thwart and then bolt the tabernacle box to the thwart. Second idea was to make a square hole in the thwart to allow the tabernacle to go through the thwart to the floor of the cockpit. One side would be flush with the cb trunk. If starting new, I would look at a “U” shaped cut in the thwart to allow the sides and back of the tabernacle to go through the thwart. The pivot pin would be about 15” above the thwart. 
 

A inconvenience with the mizzen tabernacle is that the mast has to be unpinned each time for travel and storage. 
 

In the end I went with the swivel because it gave me most of the advantages of a tabernacle without much modification to the boat. If I were building new I would probably look at the “U” cut in the thwart. And live with the ugly crutch arm for the main mast.

[Andy B]

@Don Silsbe, I'm enjoying the brainstorming of ideas I probably don't have the talent to build 

 

Cockpit coaming:  I like the idea of the flush coaming and would try it if I didn't think it would turn out looking like a hack job.  But for you, since this boat is intended to carry you through your dotage , I would ask how often you think you are going to be sitting up on the rail?  If not often, then you won't be taking advantage of the flush coaming, just the disadvantages of slightly more wet seats.

 

If anything, I would extend the coaming all the way down to the seats to create a sizeable backrest, all the way from butt to middle back.  Leaning back on that would be a pleasure.  You would lose a bit of storage under the thwart (mainly for oars), but you've already stated that this is going to be a daysailer, not a cruiser, so I think that's a good tradeoff. 

 

[Don Silsbe]

@Reacher  I assume you haven’t seen a lot of mark 3’s Down Under.  Let me show you a few as relates to the subject of a tabernacle.

 

First, the mizzen remains pinned, and swings FORWARD (!).  Because of power lines at the launch site I used, I needed to launch Jay’s 20.3 (that he built and I bought) as-trailered. I had to raise the masts as she floated at the dock. If you zoom in, you’ll see that the aft edge of the tabernacle is even with the aft edge of the thwart.  On this boat, the mizzen is secured down low, about 3” above the cockpit sole.

On Steve Warfle’s Skeena, the thwart is more aft.  Also, the mizzen stops at thwart level.  I’d probably favor Jay’s solution, but I have no good reason for it.

 

Also notice that both tabernacles have a crutch for the top end of the other mast.  I am confident that I could currently handle some sort of mizzen funnel, but I’m less confident that it would become more and more cumbersome “into my dotage” as Andy puts it.  I want to sail right up until I am admitted to the Assisted Living unit.  LOL

[messingdd97]

Hey, Don:

 

If you decide you want a long shaft Suzuki 2.5, I've got one that I'd trade. I'm planning to be at the messabout, and could bring it. I've also got it listed for sale if you're interested.

 

David

[Don Silsbe]

@messingdd97  Thanks, David, but I think I’ll stick with what I have.  I’m going to equip the boat to handle my short shaft as well as an electric trolling motor.  Most of my sailing will be on reservoirs.

[Reacher]

Don, you are right, I haven’t seen a tabernacle like Windepedent! In fact, looking at the picture I still can’t see how it measures out. On my 20.1 either way I swing the mast the top of the mizzen would be out in traffic.

 

I just realized that I have never seen a mark3 of any length. That probably shows in my comments.

[Don Silsbe]

I understand, Reacher.  In the photo above of Windependent, you’ll see that the masthead light on the main is pointing aft.  The masthead float is forward.  I remove that for travel, of course. Here are some photos of Windependent with the masts down and ready for the road.  You are correct in that there is a lot of overhang, especially aft.  This is mitigated by the boomkin and the rudder being in the up position.  Jay is handy with a sewing machine, and made covers for the mast and rudder.

 

 

[Don Silsbe]

@WindyBeard. Look at the above photo of Skeena,, the one from the stern looking forward.  See the fin on the Suzuki long shaft?  When you swing the motor around for reverse, the fin needs to clear the transom.  This requires you to notch the transom regardless.  Other long shaft 2.5’s might do better.

[Mike Vacanti]

The bolt-on style of motor mount that Alan had on his CS17.1 that I copied on my CS17.1, allows the Suzuki 2.5 to rotate 360 degrees without touching the transom.

[WindyBeard]

Hey Don,

 

Yes, a notch like Steve or Amos or others have and a recessed deck was what I had in mind.  Since I won’t buy a motor until I’m well into the build I figure I can plan the notch accordingly but I’ll gladly take any advice.  Your mount seems to put the motor pretty far back… does that weight hanging out there cause any issues?

 

 Thanks,

 Derek

[Don Silsbe]

@WindyBeard   That bolt-on metal bracket was what I did on my previous boat.  I should have notched the transom.  It worked fine, except that the motor wouldn’t latch in the tilted position.  I needed to get creative.  This time, I’ll do it right.  I’m building a partially completed kit started by someone else.  I’ll do it right this time.  Here is the link to Alan’s photo essay of his transom modification:  

https://photos.app.goo.gl/dnbRVtpFxNTxV5o16

[Steve W]

"On Steve Warfle’s Skeena, the thwart is more aft.  Also, the mizzen stops at thwart level.  I’d probably favor Jay’s solution, but I have no good reason for it."

 

FWIW, if I was to do this again, I would have not put the thwart directly in the center of the mizzen. I would have moved it aft about 4" with the mizze right where it is or make it wider. The reason is that in light air I find myself wanting to move to the center of the boat to keep it trimmed properly. As it is, I have a cooler that I can perch on, but it's not handy. As for the opening above the thwart, I designed as provided by Alan. The glass Douglas fir isn't going anywhere. 

 

The other mod I'd make is to extend the tabernackle 6" higher. When the masts are down, access to the cabin is not great and it wouldn't take much to make it way better. But that's for Mark III's. 

[Hirilonde]

2 hours ago, Steve W said:

The reason is that in light air I find myself wanting to move to the center of the boat to keep it trimmed properly. As it is, I have a cooler that I can perch on, but it's not handy.

I sail a different boat, but I find that every small boat I have sailed I try to get as far forward as humanly possible. I go right up to the cockpit coaming in my Lapwing using the tiller extention. Wetted surface matters more than the shape in the water, so long as the board and rudder are still wet enough.

[Steve W]

Dave, it's true. I sail with a lot of other boats who are often "dragging a#$". Skeena is big enough I only need to get to the mizzen, and I pack gear to compensate when I have crew. I do have a bubble level on the thwart just to be sure. The problem I try to address is side to side trim. My constantly evolving data says keeping Skeena sailing on one of the flat panels slightly healed is fastest in light conditions. I think it's probably due to keeping the sails full and driving, and sometimes I find being on the leward side is too much heal and on the windward not enough.