Building Core Sound 17 mark 1, #414

[Don Silsbe]

As some of you know, I’m buying a partially-completed kit.  I’ve put down a deposit, and will pick it up later in September.  I’d rather not jinx the sale by posting this, but I’m neck-deep in planning the build.  I have questions.  I’m looking to my friends here on the forum for your opinions.  The first question appears in the following post.  If you’re wondering why I sold Jay’s Southern Express,  IM me.  I’ll be happy to discuss that with you.  Meanwhile, here is a photo of my final objective.  Yes, this is the boat I had before Southern Express.

[Don Silsbe]

So, the first question is about mounting a motor.  The kit is the aft deck version, which I like.  I have a short shaft Suzuki.  It needs to extend below the transom, yet tilt forward when under sail.  I see my options as:

 

1.  Notching the transom deeply, adding a well, and using my short-shaft.

2. Not notching the transom, but adding a well, and buying a long shaft.  Do I still need to make a well for this?

 

3.  Only adding a tall plate to the transom, tall enough to tilt a new long shaft.

 

4. Adding an external commercially-made motor mount for a long shaft motor.  On my previous mk1, I had to mount it so low that it wouldn’t tilt naturally.  I need a long shaft to do this, or add a shallow well.

 

What has been your experience?  What have I not thought of?  Which would you choose?

[WindyBeard]

I think for my mark 3 I’ll be doing option 1 but with long shaft. But this is based on reading what everyone else has done, not on any experience of my own. 
 

I’ll be closely watching what you do; you’ll likely be slightly to moderately to majorly ahead of me the whole way…

[Paul356]

I have an external mount with a short shaft that tips up.  Will try to get a picture.  Not sure the mount is made any more, tho.  Got it thru duckworks.  Would be really interested in hearing your thoughts on going fromt the cabin model to the old Mk I, which I have.

[Don Silsbe]

@Paul356— It has to do mainly with my realizing that my appetite for adventure has diminished dramatically in the past few years.  If the weather is lousy, I’d rather stay home.  It’s not worth having a cruising boat.  
 

I’m very interested in seeing what you did.  I love my Suzuki shortie.  The long shaft has a hideous fin above the cavitation plate that keeps it from solving the problem.

[Don Silsbe]

@WindyBeard— The mark 3’s are a little different configuration than the open daysailers, but I’m happy to have you tag along on this conversation.

[Don Silsbe]

Does any body use an electric trolling motor?  My little 30# thrust motor is the same length as a long shaft.

[Don Silsbe]

@WindyBeard— I’ve been searching the forum, and found this from Graham on the subject.  Amos was building his 29.3 at the time.  It shares the detail of Gram’s experience on the subject:

 

I do not think that you can make a well work on the 20 if you are staying in the 2 1/2 hp range. Your freeboard is a bit taller than the 17. If my freeboard was 1/4" taller or more it would have gotten ugly. The reason is that there is no reverse and you have to turn the motor 180 degrees for reverse. The problem is that the exhaust curves back over the cavitation plate which swings under the bottom of the boat in reverse. If you cut the well deeper, the cowl under the motor will hit the transom.  Mine clears the bottom by an honest 1/4" and the cowl clears the transom top by less.

 

Before everyone says just get a long shaft, the shaft extension goes under the exhaust / cav plate and does not solve the problem. I put mine to port before I realized my error because the tiller is to port which comes very close to the cockpit coaming. with the tiller down I can turn the motor a couple of degrees to port without hitting the port cockpit coaming. It just allows me to tune the motor for straight running with the tiller down. I can only reverse the motor by turning it 180 to port but only after lifting the tiller 90 degrees. 

 

I am not finding this a big deal in real life but it would be more elegant if the motor was to starboard. With the tiller lifted I can vector the thrust each way for tight maneuvering and fortunately the motor has a clutch, so swinging it 180 degrees is not difficult. When I turn the motor to rotate the boat I am glad that it is only 2 1/2 HP because it really turns fast.

[Andy B]

10 hours ago, Don Silsbe said:

Does any body use an electric trolling motor?  My little 30# thrust motor is the same length as a long shaft.

Alan used a trolling motor (maybe 55#) at Raid Erie for his 20 mk3.  It worked okay to get in and out of the marina and do a little motor sailing.  I think he said it would not work well against wind/waves/current.

 

But his was in a well.  I was thinking about a trolling motor, but with the battery cable and higher head, that's just more hanging around the transom for my sheets to get caught on.

[Don Silsbe]

When I was employed as an engineer, I learned to not only trust the drawings, but to consult others to learn from their experiences.  So, I first posted this on the forum.  Then, I went through all the build narratives I could find.  Then, I made my drawing.  I started 10” from the centerline of the boat, then tried 14.5”, and finally 20”. (Trial numbers 1, 2, & 3 respectively.)  Each iteration made the notch in the transom smaller (vertically).  I then transferred Alan’s Southbound centerline to the drawing.  The conclusion is that the 14.5”. Is slightly outboard of Alan’s 13”.  I think Graham’s Carlita is closer to the 20” trial, but I think he did that to avoid the boomkin.  What do y’all think?  Should I go with 14, or go more outboard?  
 

Here’s Alan’s modification to Southbound.

[Mike Vacanti]

I bought a second hand CS17 mk1 about a year ago and the first thing I did was add a motor mount. I copied the mount on Alan's Southbound almost exactly. I mounted a Suzuki 2.5 long shaft and I have no problem tilting the motor up or reversing it.

 

The only real issue is that the motor loves to catch the mizzen sheet. I saw a mod on this site some time back where a fellow ran the sheet through a ring (I used a mountain climbing rappelling ring) and then attached a light shock cord to the ring and tied it off to the middle of the mizzen sprit. If the sheet goes slack during a tack the shock cord pulls it away from the motor. Seems to work pretty good so far.   

[Don Silsbe]

Good to hear, Mike.  I tried something similar on my Bay River Skiff years ago.  It didn’t work, and I abandoned the idea.  Maybe I should revisit it.

[PadrePoint]

7 hours ago, Mike Vacanti said:

I saw a mod on this site some time back

That’d likely be mine??  I found it helpful. 
This is a photo of my initial experiment with it… (the thin elastic cord is hanging down before I decided where to cut it.)

When the mizzen sheets become slack in low wind or a tack the ring slides down and forward enough to help things from getting tangled in my motor. 

[Mike Vacanti]

3 hours ago, PadrePoint said:

That’d likely be mine??  I found it helpful. 
This is a photo of my initial experiment with it… (the thin elastic cord is hanging down before I decided where to cut it.)

When the mizzen sheets become slack in low wind or a tack the ring slides down and forward enough to help things from getting tangled in my motor. 

That is the scheme I implemented but the fellow I copied was from overseas. 

[Don Silsbe]

NEW SUBJECT—

A TABERNACLE ON THE MIZZEN

 

 Before this unfinished kit showed up, I was going to build an Amanda to serve as my Old Man’s Boat.  The hardest thing for this old man to do on the 17.1 I had was stepping the masts.  The double tabernacles on the 20.3 were a godsend.  I’d love to have both on this boat, but I see a problem with the mizzen.  The c/b trunk is in the way.  It would also put an ugly slot in the thwart.  One solution would be to devise a mast-stepping aid similar to what I made for my first 17.1, but use it for only the mizzen.  I could always wait on this, and make it as I sail into my 80’s a couple of years from now.  But it would be better to do this in the initial construction.  What are your thoughts?

[Andy B]

Check out the "toaster slot" that the Old Salt 15 is using for its mast: 

 

 

Maybe something like this, but loaded from the aft?  Your steps would be:

1:  Put the mast in the boat from standing on the ground, aiming the base of the mast near the mast step.

2:  get into the boat.

3:  Align mast base with mast step.

4:  Raise the mast, walking aft to fore, and aligning it in the "slot" cut into the aft half of the thwart.

5:  Close the "gate" on the thwart to keep the mast in place.

 

You may need a beefier thwart (either horizontally and/or vertically") but I think that would be the easiest way to raise it.

 

[Reacher]

Don, I’ll recycle this photo of the mizzen swivel on my CS 20.1. 

 

After two seasons of use I am completely happy with it. Without the swivel and the main tabernacle I doubt if I would be using the boat.

 

The effort and feel of swinging the mizzen into position and back down is no different than stepping/unstepping the main mast using the tabernacle. It is actually somewhat easier and more secure because of standing in the cockpit rather than on the deck.
 

The mizzen does require some manipulation to slide it through the thwart and lift it out, but the foot of the mast is always contained so it is secure to handle. 

 

At this point I don’t know of any better method aside from a mizzen tabernacle. Of course you might come up with something you are more comfortable with. Good luck.

 

 

 

[Don Silsbe]

@Andy B— I saw that.  “Toaster slot” is a clever nickname.  I think it’d be too big a tear-up for a Core Sound, though.  The main isn’t the problem so much as the mizzen.  A tabernacle on the main mast solves most of the problem.  A winch for the main would make stepping even easier.  The 20.3 I had (albeit briefly) spoiled me.  That would be ideal, if I could get it to fit.  Reacher’s swivel or my removable funnel significantly reduce the effort.  

[Andy B]

2 hours ago, Don Silsbe said:

@Andy B— I saw that.  “Toaster slot” is a clever nickname.  I think it’d be too big a tear-up for a Core Sound, though.  The main isn’t the problem so much as the mizzen.  A tabernacle on the main mast solves most of the problem.  A winch for the main would make stepping even easier.  The 20.3 I had (albeit briefly) spoiled me.  That would be ideal, if I could get it to fit.  Reacher’s swivel or my removable funnel significantly reduce the effort.  

No, I mean make the slot for the mizzen mast by cutting the slot into the thwart.  That way instead of trying to get the base of the mast up on the thwart, you are positioning the base along the floor of the boat.  I think that helps in two ways. 

First is in loading the mast--you could put the mast in the boat from the ground instead of while standing in the boat.  Pick the mast up and slide the base to the mast step.  Having the end of the mast (the heavy end, too) along the floor instead of on the thwart would allow the mast to rest nicely on the transom.  Then you get into the boat.

Second, you now just start pushing the mast up as a lever, with the end of the mast resting in the base/step cup (you could even make a back stop to push against.  You never have to pick the mast up, just keep levering it up in the air, through the slot in the thwart, until vertical.  Then close the "gate" in the thwart.

You'd have to beef up the thwart, maybe even make a mast case going all the way under the thwart down to the floor. But I think the advantage of not having to pick up the entire mast would be great.

[Don Silsbe]

@Andy B— OH!  Now that’s worth considering.  That’s roughly how the Illur single mast is stepped on Roger Barnes’ boat.  It is held in place with line lashed between two belaying pins.  I imagine the same thing could be accomplished with a chock bolted into the “toaster slot”.