Building Ninigret

[Oldad]

Take a look at this thread,Thread: "Skål Sandy!” a Caledonia Yawl Build in Cream Ridge NJ

the building of a Caledonia Yawl. Glued lap (epoxy) no frames, no rivets I have sailed in Geoff Kerr's CL that was built many years ago using this method, still like new.

[stromborg]

One thing that's bugging me about epoxy is it being brittle. Something is telling me I want something with some flex to it. I've considered G-Flex to solve that worry. The other glues 5200, 4200, Sika have some flex.

The number of old epoxy-glued boats still floating around ought to dispel your concerns. What drives your idea that it is somehow too brittle?

[timo4352]

some reading on brittleness:
https://epoxyworks.com/index.php/if-...more-flexible/

https://www.jamestowndistributors.co...t.do?docId=357

my fears could be unfounded, but maybe not...

...or maybe deep down inside I just don't want to use epoxy for this build...IDK...

[stromborg]

Both of those articles come to more or less the same conclusion, the wood substrate will tend to fail before the epoxy does. I worry more about the quality of mass-produced marine plywood than the epoxy I mix up and apply myself.

My intention is for my next big build to be cedar planks on steam-bent oak frames so I get not wanting to use epoxy to hold the boat together but it is a very good structural adhesive.

[Steamboat]

Disclaimer: I am an opinionated rank amateur!

Just a suggestion, take two relatively long ( 2' t0 3') strips (3" to 4" wide) of plywood that are thin enough that you can twist them some by your hand. Make a 3/4 to 1' lap joint with a filler like wood flower or west laminating filler and let the joint cure for a few days. Once fully cured twist it until it breaks, if you can't break it bend it over something until it breaks. What failed the wood or glue joint.

One more thing to consider when building with plywood, every nail or screw penetration is an avenue for moisture to find its way between the plys.

It is your boat, do it your way!

I did! Despite numerous warnings I've made the majority of my non-plank components from locally sourced slash cut black locust. The standard is Doug Fir. I have paid a price it, any cutting, planing, shaping has taken longer and required more effort than working with DF. Oh, then there is the frequent tool sharpening and the worn out planer blades.

I am hoping to see the progress on your build however you choose to proceed.

[Falcon1]

Hi Timo,

I'd vote for no epoxy just because that sounds like a pleasant way to build, and it's what I'd like to try for my next one. But for that I'll build small, like Atkin's Nina.

Ninigret is a lot of boat to construct. Perhaps going with a method you're familiar with might be good, then go full trad. on a next, smaller boat. (I'm also considering the Norwegian Pram.)

Anywhoo, I'll be following along as usual. Good luck!

Mike

[timo4352]

Got the strongback 95% complete.
The lofting table will be on top of that.
Some kind of progress anyhow.

[timo4352]

...and finished the lofting table today.
First coat of paint on. I'll do a second coat tomorrow. Should be ready to start the lofting by the end of the week.
Maybe sooner depending on how anxious I get --- which is pretty much....

Reminds me of "the scale of the thing" thread... the lofting table looks huge in my shop.

[timo4352]

I took off work for the rest of the week for some much needed time off.
Got started on the lofting today. I don't go back to work until Monday so we'll see how far I get.
It's a start.
IMGP0075.jpg

[SBrookman]

Now you've really started! Seeing that great expanse of white is exciting and disconcerting as you can now see the size and scope of the project ahead. It's great fun seeing the shape reveal itself as those numbers from the table of offsets become sweet lines.

[Steamboat]

Good idea to take the time off for lofting, can focus and make good progress. Doing that kind of work in little snippets of time has its problems.

[stromborg]

I took off work for the rest of the week for some much needed time off.
Got started on the lofting today. I don't go back to work until Monday so we'll see how far I get.
It's a start.
IMGP0075.jpg

What is that batten made of?

[timo4352]

I made the battens from MDF. Painted black. This one is 3/4" X 1-1/2". Also cut some 3/4" X 1" for tighter bends - that worked OK for the stem on the 3/4" edge.
I had to stop - I hit a couple hiccups that are making my brain hurt... I'll go back to it in the morning - fresh.

[timo4352]

...still stuck in lofting limbo...
I have sent my question off to Pat Atkin but not sure what I'll get back...
My question:
"I am lofting Ninigret and I am having trouble figuring out the rabbet on the stem.It seems to me that I would need a height above the baseline or the LWL to the waterlines LL2, LL4 and LL6. Or maybe a note that the rabbet is a consistent width from station O to the sheer possibly?
I cannot find anything in the plans that gives me this information."
..so what I have here is no info to locate the rabbet going up the stem. It does not appear to be a constant width from the drawings.
The other thing that has me stumped is the offsets say "Dimensions given in feet and inches to the outside of planking" --- if this is the case, then when I draw the stem that line should be the outside of the planking also...no? -- but they show the rabbet drawn inside, so obviously the line is to the outside of the stem - not the planking.
What gives?
Maybe this pic will help --- those waterlines shown are LL2, LL4 and LL6 as mentioned.

Ninigret-2 (1).jpg

[timo4352]

OK - I think I got over this hurdle...
Forgetting about the rabbet because I'm thinking it will be simpler to do a two piece stem anyways....
Good thing I've got some good, big erasers on hand ...

So when I project my stem down to the plan drawing,.. and figure out my landing on the stem for the planking - I get a line I can work with. Project that line back up to the top of the stem, and measure across to the front of the stem, I get 1-1/2"...
...now I can square that up off my baseline at the LL2, LL4 and LL6 waterlines to get those same 1-1/2" points. Tap in a few nails, connect the dots with a batten, and I think I'm setup for my two piece stem. This makes my outer, or false stem that 1-1/2" thick which should be good. I hope.
Sound like a plan? Or does my rambling make any sense to anyone but me?
Maybe I just needed to talk myself through it...
Or maybe I'm dead wrong...

[stromborg]

"Dimensions given in feet and inches to the outside of planking"

That means you have been given the outside faces of a boat-shaped object and when you get around to making the frames you will need to subtract the thickness of the sheathing from the frames so the finished boat more or less matches you drawn dimensions. There are a few ways to go about accounting for the thickness but on this size boat I think you can simply subtract the thickness of the plywood and be just fine.

That also means that the drawn line of the stem is where the finished piece should end up.

The rabbet should be somewhere on the plans. Could be in the table of offsets or on the drawing as "X inches back from the face of the stem along waterline Y" or from the forward perpendicular. Keep plugging away at it, the solution should show itself as you go. Even going with a two-piece stem you will still need to find where the planking intersects with the stem, you should be able to develop that from the half-breadths once you get them drawn. I have done just enough of this stuff to be dangerous and my grasp of the subject/writing skills are not solid enough for me to get super-didactic about the applied geometry of lofting, hopefully someone more adept than I will come along. Or someone who has built Ninigret will stop by and say "Oh that is in the lower left corner of page 3".

[timo4352]

Thanks Steve
I felt like I was stuck there, and there was no sense moving forward to doing the body plan...
...but I feel pretty confident in this approach that it is safe to proceed -- if I'm wrong I still have a few erasers handy.

The planking deduction... I know that has to happen. Still contemplating just how I want to accomplish that. Seems to me taking the angled deduction off the plan lofting would be the most accurate, but yes, the difference looks minimal from just taking it right off the frames. Maybe leave them a little heavy and do a little more fairing once it's all set up.

[SBrookman]

I had just made a bevel board, per Gudgeon's manual, for figuring the plank deduction when Paul Gartside stopped by before I used it (he was teaching a class down the road at WBS) and said it wasn't necessary. Of course I took his word for it, glad to have one less calculation. Like the other Steve, I know just enough about lofting to be dangerous, to get it done, but I could be missing the finer points. So I don't know if that applies to your design or that is just how Gartside's designs work.

[timo4352]

Well i have pushed ahead and I think, pretty much, finished the lofting. This hard chine design makes doing the body plan pretty easy.

I did not have the room to expand the transom out -- so I superimposed it (in a different color). I hope that is not going to come back to bite me...

Did a quick check plotting off the LWL on the plan view and it looks good.

--So question is: with this hard chine design do you see any need for me to draw those additional waterlines in plan view?
-- and should I go to the trouble to add buttocks to the body and profile?
Or is this just a waste of time and added complication for no gain?
I'm thinking the latter, but what do you guys think?

[Oldad]

What do your lofting books say? Seems like doing it all will give a better picture, plus lofting is fun. Right?

[Gib Etheridge]

It seems to me that additional WLs, buttocks and diagonals would be useless with the straight frames.

You're going to build upside down, right? It might help later if you mark the LWL on the transom, then before you flip it you can use it and a laser level to mark it all the way around. That's also a good time to completely finish the bottom.

[timo4352]

Suddenly it occurs to me that just maybe the designer knows a bit more than me about it... He did not include any of those additional lines in his plans, most probably because they were not necessary, so why would I ?
Maybe I just answered my own stupid question... and I said I didn't want to be asking any stupid questions...
Go figure.

[stromborg]

I wouldn't add many extra lines either. However, since it will never be easier than now I would mark for things like the cockpit sole and berth tops. That will give you 3 good reference planes to check for plumb as you go forward and you'll already know where the internal framing pieces go when the build gets to that point. A laser level works but can be a bit fiddly to set up, is pestered by vibration and only works line-of-sight so inevitably the place you really want a mark will be in shadow.

[timo4352]

I have been getting some feedback from some past Ninigret builders lately, and everyone seems to be in agreement that the forefoot is in fact quite difficult to construct on this boat. So now my thoughts are leaning more towards doing a 1/2" bottom (rather than 3/8"), and double diagonal planking the forefoot.
So much for limiting the epoxy usage - huh?
Gib - you have done some strip planked bottoms haven't you? I wonder if that might be an option too? But may need to be glassed then...hmmm...

[Gib Etheridge]

Lot of twist here, so strip built garboard then glass the bottom and garboards in one piece.

rowboat 035.jpg

rowboat 036.jpg

rowboat 077.jpg

shop 005.jpg

[Gib Etheridge]

Strip built here then cold molded 2 layers then glass. Glassing is easy.

rowboat 005.jpg

rowboat 043.jpg

rowboat 140.jpg

[Gib Etheridge]

With that batten at mid-width for the garboard you should be able to lay up 2 layers of 1/4 ply cold molded pretty easily. Some would call it overkill, but glass between the layers, especially if they were not crossing, and on the outside would make it stronger.

So many options.

[timo4352]

I figured out I screwed up a bit on my lofting of the body plan. Not terrible, but I guess I'm glad I caught it now so I can fix it before I started cutting any wood.
What made my mistake obvious was by looking at what the apron would look like --- I had the rabbet in the wrong place, and the apron got real thin in some spots.
Dropping the rabbet line just that little bit gave me some meat back on the apron. I don't know what I was thinking when I drew it that first time...I just kinda made up some arbitrary line for some strange reason... rookie..


How deep do you think I should be cutting the rabbet in the keel?
The keel is 2 inches thick --- and the rabbet is to accept 3/8 or 1/2 inch planking, depend on which I decide to use.

[timo4352]

Just watched the acorn to Arabella video on cutting the rabbet, Good stuff.
And Louis's video on tuning up a Ryobi hand planer -- I have to check out my Porter Cable to see if I can improve it in a similar manner.

[DoctorB]

Timo -
Waiting with interest! It's your turn now.

[timo4352]

Sorry Doc --
I got nothin' right now.
Just re-figuring my rabbet and apron on the lofting body plan and re-drawing that part of it.
And trying to figure out what wood I'm gonna use,etc. Not quite ready to start cutting anything yet.

[timo4352]

...working out the numbers on the framing wood...
The plans call for white oak frames and keel apron @ 5/8" sided...
I have lots of tight grain douglas fir... increasing to 3/4" the numbers seem to work pretty well... All but the hardness difference, not much I can do about that.
I end up with some weight savings even with the increased scantlings, which I believe should be offset by the increased weight of the meranti ply.
Thoughts?

[timo4352]

..no cigar...
all my figuring looks like meranti will still add about 300 pounds to the hull - even with me using the lighter douglas fir framing.
Not good...
I see my plans spec Regina plywood, which best I can gather is Bruynzeel - possibly okoume gaboon.
I can't really get the answer I need on that from the Bruynzeel site - I can't read Dutch.
Homestead Hardwoods does also show a Bruynzeel okoume for 90 bucks a sheet... Okoume Mahogany they call it...Maybe that is comparable. I have to contact them about the number of plys on that one as it is not listed

[timo4352]

...
"I am lofting Ninigret and I am having trouble figuring out the rabbet on the stem.It seems to me that I would need a height above the baseline or the LWL to the waterlines LL2, LL4 and LL6. Or maybe a note that the rabbet is a consistent width from station O to the sheer possibly?
I cannot find anything in the plans that gives me this information."
..so what I have here is no info to locate the rabbet going up the stem. It does not appear to be a constant width from the drawings.
Maybe this pic will help --- those waterlines shown are LL2, LL4 and LL6 as mentioned.

Ninigret-2 (1).jpg

Well, it appears that the info to locate my rabbet is in the plans. I just need to understand lofting and boat building a little more to get to it.
In reading Chapelle's Boatbuilding, on page 109, I believe i just got my answer...
If you notice the waterlines drawn in the front half of the boat plans -- the answer is in there -- and the book just told me how to decipher it.
So I will be drawing those waterlines; just as shown in the plans to get the projections I need to locate the rabbet.
Too late now to go start this, but tomorrow I'll give it a shot and see what I come up with.
This lofting really is fun stuff...see?

[Gib Etheridge]

When I do inner and outer stems I just bevel the inner stem in place using a batten to determine how much to take off. If you pre-bevel it according to the lofting you will do well to leave it a little heavy and finish it in place using a batten as a guide anyway, so maybe you can save a bit of effort by just using the batten method only.

If you plan to laminate the outer stem it's easiest to use the inner stem as a mold before beveling.

I admire your pluck Tim. I don't much like lofting.