How to construct ribs for an 18 foot Grand Banks dory

Picture of How to construct ribs for an 18 foot Grand Banks dory
I'm building a traditional 18 foot Grand Banks dory.  The dory will be discussed in a future Instructable but thought it might be interesting to focus on how I constructed the ribs which are the heart and soul of the dory, or more properly, the skeleton of the dory which supports the entire rest of the boat.  

I have used a combination of traditional and modern techniques and a lot of help from friends and family that I refer to as the "planking crew."  

The dory is being built with plans from  Henceforth, I will refer to as the Plans.  Unless permission is granted, I will not discuss dimensions but will show my woodworking techniques.  You can purchase the Plans for $49.99 and obtain the dimensions.  The Plans are conversationally written, as I expect you would receive if you visited their boat shop and shared a cup of tea. 

In summary, the rib construction involved learning the traditional building method from The Dory Book, harvesting white oak logs with a major branch sticking out at nearly the correct angle, milling the logs into 1 inch thick boards, drying boards in solar kiln, planing boards from 1 inch down to 3/4 inch (20 mm) thick, using a plywood form to mark and rough cut the rib shape from the oak board, use the same plywood form and a router to create the final rib shape, and join 2 halves with a finger joint for installation.  Each of these tasks will be discussed in detail in the following Steps. 

A word on nautical terminology.  There is a lot of it and I'm just learning it.  Jack left port (i.e., left = port) is my starting point.  And there are multiple words for the same thing.  Ribs = frame = brace = knees and sometimes are combined like knee brace.  I'll use "ribs" throughout.

The primary purpose of the dory is to carry picnic supplies and picnic princesses (i.e.,  persons not rowing) to islands off the coast of Maine.  There are a lot of picnic princesses in our family, hence, why I am building an 18 foot boat.  

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Very nice work.
But filling epoxy into gaps in a piece of wood will not make it stronger : wood will break along the side of the filling. A rib should not have any knot it the wood.
Also scarf joints should be preferred to finger joints as they have a much larger gluing surface. A good scarf should be 12 times the width of the wood piece.
Thanks for sharing.
dorybob (author)  vincent75201 year ago
Vincent - Attempted to reply earlier, so this may be a duplicate. All your comments are spot on. Being a rookie boat builder, I thought that cutting a finger joint with a router bit would be easier than planing a scarf joint. I was afraid of scarf joints but learned not to be, thanks to lots of internet help. The scarf joint is much stronger. I've placed additional supports across most finger joints. I think she'll hold together. Thanks for your comments. DB
Glad to help.
Don't worry about being a rookie… I was for 5 years wile refitting from top to bottom - actually from keel to mast… ;) - my 30 ft blue water sailboat. That's why I feel I can share my experience.
You are right by making your first experience in boat building with a doris : excellent boats and you will learn most of the basic boatbuilding techniques with them. Not only that, you will also have a great boat that will reward you in pleasure at sea and make you comfortable for further, more important building. There are many bigger dories that are cruising boats that sail around the world : so you couldn't go wrong (I have the book somewhere in my attic, if you need the reference, let me know)
As for epoxy : this a great resin and the best choice.
Still it is well to learn how to use many "additives (?)" (such as wood pulp, silicate, etc… name change with brands) and how to make various joints with resin : it will be a great help.
However 4 important things you should know about epoxy (there must be more, but they are the only ones that come to mind right now. Then again I am well aware that you sure know most of it already !…) :
1) Never over tight your joints when using epoxy. Even when it is used as a "glue" there should be a tiny film of resin left between the joint (as opposed with a wood glue where the joint has to be extra tight to hold firm).
2) Do respect temperatures and humidity conditions given by the manufacturer; better be careful than sorry : I did see some joints that had to be redone. Didn't happen a lot, but it did happen. If conditions are not good : postpone or work under shelter with proper conditions.
3) Depending on how you work, epoxy can be very messy. Myself I am messy by nature (sigh !…). When using epoxy in great quantities I quickly realized I could become an absolute mess !!… Fact is that as you use gloves you do not realize that they become sticky and you climb up a ladder to get on the boat, then you seize a hammer or a staple gun and etc… Soon everything become smeary and you only realize it when you take your gloves off and grab your tools or descend the ladder : your hands get gluey you get furious, etc…
The ideal (which is never realized) would be to have a working space as clean as a lab. If you are wealthy enough, get a few basic tools, such as hammer, a couple of pliers, etc… only to be used while working with epoxy. Otherwise they will be smeared at one point or another.
4) Last but certainly not least. Protect yourself : gloves at all times, mask and goggles. Be aware that EPOXY IS ALLERGIC : not at all times nor with everyone… But I have 2 friends who worked with epoxy for some time and who suddenly started to have rashes and / or eye sores that were extremely painful so they had to stop using the stuff altogether. Now (ten years after !) they cannot enter a place where epoxy is used without feeling itches …
Once again, better be safe than sorry.
So the best policy is : use latex gloves that you throw away after each use, buy cheap tissue overalls in bulk and use each only once (ie. throw it away after a day's use), use chemical masks (dust mask are no help).
Get rags by the ton : use them and throw them away immediately after use.
Do not attempt to clean rollers or brushes with acetone. Buy the cheapest ones in bulk and throw away after one use. Cleaning them with acetone will overexpose you to the solvent and make you spend more expensive solvent than needed. Brushes and rollers must be considered as expendable in the budget.
However, cleaning your tools with acetone is OK.
BUT do use a special epoxy soap for your hands (epoxy manufacturer's catalog should provide) : not only it works much better than any other solvent but its the only safe and healthy approach.
NEVER use acetone for your hands : as acetone is a grease remover it also takes the sweat and slight natural greasy film that protects your skin, thus making it easier for acetone to get through it and enter your blood and system.
I don't make this up : I read it in an official report from the French secretary of labor (I know we have a reputation of laziness, but in this case it may prove to be useful !!!… LOL).
Of course this caution is of no concern for someone who uses epoxy once a year or so. Boat building is another matter as, for quite some time, you will be exposed to the stuff as much as a professional is.

Enjoy your boat building : this and sailing is so rewarding !…

When you have more news, let us know and post !…

Have a nice week end and forgive my typos and spellos (english is not my mother language).

dorybob (author)  vincent75201 year ago
Vincent (or more properly, Monsieur Vincent), Again, I agree with all your comments. Being an environmental professional, I have attempted to limit my exposure to all toxins, whether it is chemical, dust, or noise. I have been impressed with the Entropy resins as they are ~1/3 natural organic materials. Maybe a little less toxic than other resins. Good ventilation also helps.

Over the winter, I enclosed my workshop to maintain heat and the proper drying conditions. I wore a respirator with organic vapor cartridges. Before entering the home, I had to take my clothes off outside because even they absorbed the paint odors. Very chilly! We all need to avoid poisoning ourselves so that we can enjoy our sailing adventures. I look forward to the Spring (Printemps), warmer temperatures, and the open doors of the workshop.

I will prepare updates as I proceed. Bon Chance.
Glad you enjoyed !
This also may help other builders. Help it does anyway !…

But please no "Monsieur" … I'm not that kind !!! :D

Enjoy glorious sailing !…
NuklearTaco2 years ago
NuklearTaco2 years ago
I finally got it to work to load a picture on. This is more on the line what i was talking thats what there called "outriggers", i've always called them yauties. These fishing boats are usualy run by a diesel engine. Thanks for helping out too!
boat.jpgboat 2.jpg
dorybob (author)  NuklearTaco2 years ago
Wow. Those trimarans are beautiful. You may have already seen the following but I really enjoy both Tim Anderson and Wade Tarzia's Instructables about their boats and boating adventures:

NuklearTaco2 years ago
I live in the Philippines and fishing is what the whole place revolves around. The normal sized fishing boat here is about 30+ feet long. And most of them have the yauties on the sides wich balance the boat. I tried to put a picture on but it wont let me, but to give you and idea of what i'm talking about go on google images and type fishing boat philippines. I've looked for some plans/blueprints of fishing boats but i can't find any.
dorybob (author)  NuklearTaco2 years ago
Dear NT, Sounds like you might be talking about a double outrigger sail boat as described below:

I assume that the outriggers = Katig = yauties??

Plans are difficult to find but here may be a start:

With the main web site:

Others have asked your question but no easy answers. You may have to visit local boat yards.
dorybob (author) 2 years ago
Dear NT, Not sure what you mean by yauties but a drift boat is a nice fishing boat. They seem to be popular out West (e.g., McKenzie River Drift Boat) A drift boat is basically a modified dory. I searched for drift boat plans. One set of plans I found = One of several drift boat builders = If this is not what you're looking for, get the correct spelling of yautie and maybe I could help more. Also the following is not a fishing boat but is a simple boat plan, the Puddle Duck Racer = Looks like a fun boat. Take care, dorybob
NuklearTaco2 years ago
Hey, i was wondering if you would know any good places to look for fishing boat plans. Such as the ones with the yauties(sorry if wrong spelling) on the sides.
dorybob (author) 2 years ago
Thanks for the kind comment.
What a cool build! Thank you so much for posting this project on the site.