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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Thu Oct 08, 2020 9:55 pm 
Diamond Grade

Joined: Sun Dec 14, 2014 4:28 am
Posts: 1192
Oh crap, I want more pics, I was really enjoying the build.
So you just paint this up, with maybe a glue water coat, and thats it? No fiberglass for strength or anything? And you say you get 3 yrs or so?
I haven't built one yet, but love reading about builds, have mostly read about fiberglass on thin plywood though.
Keep posting ;)




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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Thu Oct 08, 2020 10:42 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
To be honest I have ho idea how long this particular plywood that I used will last. It's from Chile if I remember. Some kind of softwood ACX anyways. I think they advertise it as underlayment. I did not find any voids in the middle ply, but there were some small knot holes in the C side. I've had boats I couldn't trust as season, one I built out of cheap sheathing plywood (garbage) delaminated in the first ten minutes. But if it's decent ply and you keep paint on it it'll probably last a couple seasons. Gotta prick it with a knife once in a while to make sure.

The glue I was talking about is just watered down wood glue. I learned about it on another website. Ply wood tends to fall apart starting from the outside edges working in. Not always. Sometimes it its checked (cracks in the outside plys) too much to be safe. Gotta keep an eye on it. I just painted three or four coats of wood glue watered down by about 1/3rd onto the exposed edges of the plywood. Just the end grain. It soaks in pretty good. It should keep any water from creeping in when the paint on the chines rubs off, I think. Just tried it I'll let you know.

As far as paint- yeah i paint everything with 100% acrylic latex house paint. Floor paint of I can find it. I tried that paint with the primer in it already, it isn't suitable IMO. Keep paint on everything. It doesn't just keep the water out, it makes it easier to see if I damaged the plywood or if it is wearing out.

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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Sun Oct 11, 2020 9:00 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Here are the PDF plans for Herb McLeod's One Sheet Skiff. Cool little boat but it really is too small with too little freeboard to be used for much of anything but messing about. This link describes how to build one. Link from Duckworks-

https://s3.amazonaws.com/plan_downloads/OSS.pdf

https://duckworksmagazine.com/14/designs/oss/

The construction of my skiff, The Model F Special, is most exactly the same except for some butt joints or scarfs in the plywood.

Took my skiff out today. It floats and did not come apart. Paddles with a bit of a walk, which could be solved with a skeg added, but it isn't bad enough that I'm worried about it. I was using a nine foot paddle. A shorter paddle might have paddled straighter and faster but it would also drip cold water on my hands. The seat is a bit too far forward to trim out correctly when paddling. This boat would trim out great if I put oar locks on it and it does have a bit too much rocker. I didn't measure the draft with me in it, but I would guess it is about 4" with me in it and maybe 4-1/2" with a small load of gear. I also should have added a couple more 1-1/2"x5/8" battens across the bottom from chine to chine. I used four, probably will stick in another one or two.

I'm not really sure how to build one with less rocker yet still having parallel chines and sheer in the sides without messing with the flare on the frame, maybe make it 17* instead of 20*, but then that would probably change a lot of stuff...

Maybe that'll be The Model G. The design points were a two sheet boat that's easy to build.

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 Post subject: Building The Model F Special
PostPosted: Mon Oct 12, 2020 4:50 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
To get started building the model F special you will need some simple hand tools such as a pencil, rule, a bevel gauge, a 10pt or finer hand saw, a block plane, an electric jig saw, and possibly a table saw if you cannot find reasonably clear 1x2" material which you probably won't find anyways so you will need a table saw. I used a $100 bench top 10" Chinese table saw that I paid $150 for because of the tariffs. All the table saw is needed for is ripping 2x6" or 2x8" into 1x2", but it can aid in cutting out the stem and frame parts as well.

The first thing you need to do to start is to lay out the 1/4" plywood sides and join a four foot and eight foot 12" rip off off your two sheets of ply wood. Just rip one 12" piece off one sheet and two 12" pieces off the second sheet. Then cut the one cut from the middle of the sheet in half to two 12"x4' peices. You want a factory edge on the joined edges when these peices are joined with a butt block.

To make your two butt blocks, crosscut 8" off of your 24"x8' peice of 1/4" plywood. Rip your 24"x8" peice to two peices 10-3/8" by 8". The blocks will be left 1-5/8" short of the chine (bottom) of the sides. Join your side sheets to make two sides 12" x 12'.

Clamp your joined sides together face to face, A side of the plywood, with the butt blocks facing outside outside. Cut the two sides together to assure they are exactly the same.

Measure 12" back from the bottom edge of the 8' sheet towards center on your side, this will be marked (by you, both sides) "Bow". Measure 6" forward of the 4' butt edge bottom side and mark "stern", both sides. Cut the angles off from chine measurements of 12" and 8" to zero inches at top of sides. This will complete the plywood sides peices of your boat. Save the drop from the plywood, you will need the two triangles cut off the bow for frame gussets.

Stay tuned.

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 Post subject: Building The Model F Special
PostPosted: Mon Oct 12, 2020 6:21 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Next you will need a frame. The frame is placed 6'-6" from the tip of bow.

The frame will be made from 1"wX1-1/2"h lumber ripped off of your 10' 2x4. The bottom of the frame will be 32-1/2" across. The sides must fit flush to bottom of frame, so your crossbrace on the bottom will be in the neighborhood of 29-1/2". Flare to the sides will be 20 degrees. The easy way to do it is to set your table saw miter gauge at 70 degrees, crosscut a 1"X11-1/2" with the 1-1/2" side on the table on both sides to a length of 29-1/2" on the short side. Use two side peices of 1"X11-1/2" with a 70 degree crosscut for the sides of your frame. I like to leave the frame sides at least 6" longer than finished length, so I would cut the sides of the frame at least 18" on the short side.

Use the drop from the bow of your plywood sides to make gussets for your frame. If you want to be a craftsman you can make your gussets with the center ply perpendicular to the bisection of the apex of the bottom of the frame and diagonal to the bottom crossbrace. Or whatever, it does not matter a lot. Cut both your gussets out clamped or screwed together so they are exactly the same, making sure there is a 70 degree angle on the bottom. Glue your frame together with the gussets. Mark the side of your frame with the gussets "Aft" or "Stern", and the opposite side without gussets "Forward".

Stay tuned.

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 Post subject: Building The Model F Special
PostPosted: Mon Oct 12, 2020 7:27 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Next you will need a stem peice. This will have a 45 degree angle on the edge and should be at least 18" long and better 24". I'm a hack so I just ripped a 45* down a 20" peice of 2x4, but I was in a hurry. The correct way to do it is to rip a 22-1/2 degree off each side of your 2x4 stem piece. This is tricky to do on the table saw without flying fingers.

So, unless you want to be called Nine Fingers for the rest of your life, here are two safer ways to cut your stem-

1. Take a 4' 2x4 and rip it 3' down each side, the cut your stem out of the middle.

2. Rip it at a 22-1/2* out on your table saw, but hold the blade down about 1/2" from cutting all the way through. After both sides of the stem are cut half way through you can either finish it with your hand saw or if you are a hack in a hurry like me just split it off and clean it up with your block plane.

Stay tuned for transom instructions. If anybody has any questions, ask any time.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Building The Model F Special
PostPosted: Mon Oct 12, 2020 9:54 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
The first step to making the transom is to take your 2' wide sheet, the one you cut you butt blocks out of, and draw a square line off the factory edge somewhere within 15" of where you cut the butt blocks off. This line will be the bottom of your transom. Measure 14" from that line towards the end you cut the butt blocks off of. This will be your sheer line. In mark the center line of your rectangle. Now, at the bottom of your center line measure to 10" off center each side, and cut from 20" wide total at the bottom to nothing, leaving it 24" wide total. You transom us now an inch long on top, give or take. This is good. Some people like to round the corners and leave it high. On The Model F Special #1 I just marked a point a half inch high of the sheer and cut the top of transom from the corner of sheer to a slight peak at center of top. If you make it straight it isn't wrong, it just looks stupid.

Next you need to frame out your transom with 1"X1-1/2" peices. You will need sides to run from top to bottom and crossbraces cut to fit between them. But, the outside edges of the sides and bottom will be beveled to a ten degree angle on your table saw, or you must use your block plane to cut this bevel after the dry fit. The transom fits wider inside the boat than outside the boat, so if you are using a block plane leave your transom framing hanging proud about 1/4" from your plywood on sides and bottom.

Stay tuned for dry fitting the frame, stem, and transom to the sides.

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 Post subject: The Dry Fit
PostPosted: Tue Oct 13, 2020 10:38 am 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
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The purpose of dry fitting (fitting without glue) is to check or mark your bevels on stem and tranosm, to mark the notches in the frame for the chine logs, and to accurately align the peices so that when glued you can use these holes to line everything up again.

Put your boat together upside down. First screw you sides to your frame with two screws each side. Your butt blocks go inside the boat, short of the chine. The frame is placed square to side 6'-6" from the tip of the bow. The sides must be placed with the inside edge of the plywood ever-so-slightly above the bottom of the frame, maybe a pencil width. The outside of the hull side will stick up higher than the inside edge. Line your sides up equal heights above bottom of frame and better the sides be too low in the hull than too high.

Next fit your stem peice. Screw it with two screws each side. The stem must hang over at both sheer and chine. I like to leave more hanging over the sheer than the bottom. The stem will be cut to length with your handsaw before the bottom is put on.

Lastly the transom is fit. It is placed with the bottom edge flush to plywood flush, or failing that ever-so-slightly low relative to the sides. If you already cut a ten degree angle on transom framing the dry fit us done.

If you still need to bevel your transom sides, fit the sides tight to plywood stern of transom and leave it loose with a gap on the inside of the boat. Use your bevel gauge to determine your bevel. It should be in the neighborhood of ten degrees, but you don't need to know that. Just stick your bevel gauge with the stock against the chine and sheer inside the boat and blade of you bevel gauge against the top and bottom transom crossbraces. Transfer these angles to top and bottom of transom. Plane the bevel down to the line marked. Or, if you are a hack in a hurry you can just rip the bevel into the transom with your circular saw.

Next, marking and cutting notches in the frame...

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Tue Oct 13, 2020 3:59 pm 
Diamond Grade

Joined: Sun Dec 14, 2014 4:28 am
Posts: 1192
This is awesome, thx!!


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 Post subject: Notching the frame
PostPosted: Tue Oct 13, 2020 5:59 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
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I'm glad you appreciate it Dave. {hs#

To mark the notches in your dry fit frame you will need a try peice. This is simply a short peice of 1x2" , maybe 6" long, with a 20 degree angle ripped into the edge so that it mimics your chine log. Place the narrower face of your try piece against the side at the frame with the bevel up (towards bottom of boat), and flush it up to the bottom of sides on the inside of the side, right where your chine log will go. The long side face of beveled edge should be flush with the bottom of the frame. Using an extra sharp pencil, mark the outside of the try peice on your frame both sides fore and aft and both port and starboard.

Remove the frame from the dry fit. You might need to put a temporary brace in between the sides, or just disassemble everything. Join your marks across the side and bottom of frame. This notch must be cut out as precisely as possible with your handsaw. Better a pencil line too deep and too wide than too small, so cut to remove the pencil marks. Reassemble the dry fit and check the clearance with your try peice. If there is about 1/8" gap or less of wiggle room, that's good. If it is more than 1/4" gap, you can probably just throw your frame away and build a new one. If it is too tight you will need a wood rasp to finish the notch.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Building The Model F Special
PostPosted: Tue Oct 13, 2020 8:39 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Once you are confident that your chine logs will fit, you may glue the assembly together. First put the frame in and secure it with your Tightbond III and four or five wood screws. Next glue and screw the stem, then your fitted transom. I like to not put screws where the gunnel is. Doing so will interfere with fasteners going into the sheer clamp at transom and stem later. Before the glue starts to set you must make your transom parallel to your frame. There are two ways to do this, and I would recommend doing both-

With the bottom of the facing hull up,

1. Measure diagonally from port frame to starboard transom, and from starboard frame to port transom. Push the hull to shape by making both diagonal measurements exactly the same. Then, make sure the measurement along the sides is equal from transom to frame, port and starboard. Brace it diagonally with a stick of scrap and a couple screws to hold it in place.

2. Mark the center line on your bottom stem, frame, and transom. Put a small nail into centers bottom stem and transom to hold a taught string. Mason's line is best, but kite string or fishing line will do. Stretch your line between stem and transom. To account for the rocker, put the line inside the frame. This line is now literally "straight as a string". Take your square and place it on center bottom of frame with the blade facing down towards the line. When your frame center is directly in line with your stem to transom line the hull is as straight as it is going to get, especially if your sides are different lengths. Brace your hull in place until the glue has cured.

Pour yourself a drink and wait for glue to cure.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: 1 X 2 Stock
PostPosted: Tue Oct 13, 2020 10:44 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Okay, it's getting late today. Lock up your tools, unlock your liquor cabinet (if you are so inclined), and forget about using power tools until tomorrow. Let me tell you about the 1"x2" stock that you will need.

Try finding 1x2" twelve or 14' long and you might get lucky to find some horribly expensive trim moulding that will do, but if you got a table saw-

Find yourself a spruce/pine/fir 2" x 6" or maybe a 2" x 8" longer than your hull. You want a board that was cut from the core of the tree. The end grain of the board you are searching for will look like this-

|((((0))))|

Make sure it has few or better no knots, and definitely no loose knots. You need this board to be straight enough to rip on your table saw, so you don't want any crook or warp. Bent a hair to an edge is okay so long as you think you can hold it up against your fence when ripping.

Clamp your bench top ten inch (preferably American made, or at least a Delta) to your bench and set your fence at 5-1/4" or whatever you need to do to rip the broken edge off the outside edges of one side of your 2x6. To do this- you will want to rip your board about three quarters of its length, stop the power and wait for the blade to stop, lift the board out of the cut, turn the board end for end, and continue your cut to meet the cut from the other end in the middle of the board. Then, set your saw fence at 3/4" and rip five rips off in the same safe and sane manner, flipping the board end for end to meet each cut in the middle. You might not meet exactly each cut, but that is easily cleaned up with a few swipes of the block plane. No, it is NOT easier if somebody tries to help you. Trust me.

You will end up with five 1" X 2" sticks. The end grain will look like this-

1. |((|

2. |((|

3. |0|

4. |))|

5. |))|

Now, numbers 1,2,4, and 5 can be essentially interchangeable as sheer clamps or chine peices. 1 x 2 number 3 is my keel peice. When you apply your chines and sheer clamps you will want to pay attention to the crown in your one by two. The cup of the grain wants to face the center of the boat, crown facing away from center- especially on your sheer clamps.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Installing The Chine logs
PostPosted: Wed Oct 14, 2020 7:02 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
To install your chine logs you must first throw your tape measure away. If I catch you using it I will reach through my computer screen and take that thing away from you. You don't need it, you don't want it. A tape measure will just confuse the matter.

Choose two of your 1x2 and orient them so that the crown will be facing the plywood side, 2" face against the plywood. Mark them both fore and aft and port and starboard so they don't get mixed up. Then, rip a 20* or maybe slightly less angle in the edge of the 1x2. The drop from your rip will be most of what you would have to plane off latter if you do not have a table saw.

You will need about ten, maybe a dozen clamps. Spring clamps work swell. Your chine log fits flush to the Inside Edge of your plywood side. The Outside Edge of side will be above that, it will be planed into place later . At frame the beveled edge should fit flush to frame bottom. Take your bevel gauge and place the stock on your sides at the stem and use the blade of your bevel gauge to get the angle between chine and stem. Cut this bevel into the forward end of your chine log. Check fit.

Now, take a measurement of the bevel at the transom and transfer that bevel to the aft end of the chine log making sure that the bevels are further apart than the finished peice will be. Put your chine log into the notch at frame and bend it down and in until the forward bevel fits into place. Then, clamp the chine in place against the side up to somewhere past the frame. The aft end of you chine log should be resting on and above the transom. Scribe a straight line across the chine log and down onto the outside of side. Next, place the aft end of chine log against the transom and clamp in place up to somewhere forward of the frame. The forward end will be sticking out over the bow. Transfer your mark from the side onto the chine log. You now should have two marks on your log. The distance between these marks is how much need to be removed from the log to fit it. Measure this distance with two marks on a stick of scrap, then measure from aft bevel of chine log forward that distance. Cut the exact bevel you just cut but on the new mark.

Once you have fitted your chine log you may clamp it in place, with glue, and screw it every six inches or so. Make sure that your screw heads are ever-so-slightly below the face of your plywood. If the screws stick up you will nick your block plane on them while planning the bottom into shape later.

Sharpen up your block planes boys! Next we plane the sides to fit the bottom.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Building The Model F Special
PostPosted: Wed Oct 14, 2020 9:30 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Quote:
...Next we plane the sides to fit the bottom


No wait, we don't do that next at all.

First your boat will need sheer clamps on the gunnels. Easy, the peice will fit outside the hull. You can cut it to fit after the glue is dry. Dry fit your sheer clamps with spring clamps to be sure they will take the bend without breaking. Put the crown of the grain facing away from the center of the boat. Glue and screw the sheer clamp through the plywood every six inches or so. Put a 1-5/8", maybe 1-3/4" screw from the outside of sheer clamp into the stem and transom.

You might be tempted to put a long screw into the frame through the sheer clamp. Well I wouldn't do it that way if I were you. The apex of that bend at the frame is under both tension and compression. You probably Do Not want to put any extra holes there.

When you add the second sheer clamp it will intersect with the first one at the bow. Cut just enough off the first one installed that the second will fit. Then you can cut both sheer clamps together to finish size with your hand saw.

Now prepare your block plane.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Thu Oct 15, 2020 2:43 am 
Diamond Grade

Joined: Sun Dec 14, 2014 4:28 am
Posts: 1192
Yaaaaas!


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 Post subject: Planing The Sides
PostPosted: Thu Oct 15, 2020 12:13 pm 
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Joined: Tue Jan 08, 2008 10:15 am
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To use a smoothed, polished, and tuned block plane is a joy to do. To try use a dull block plane is an exercise in horribly excruciating frustration. When you purchase your block plane buy a sharpening stone or stones, and a sharpening roller guide. The back of your plane iron (blade) should be polished smooth into a perfectly flat plane, and I mean perfectly. You should be able to place the back of your iron against a small plate of glass with a bit of water between glass and iron and can pick the glass up by lifting solely on the iron. If you try it, when you pick up the glass with your iron look underneath and you will see that the water is tight to the steel with no bubbles or gaps. Yeah, perfect! The beveled edge of the plane must also be smoothly polished- and Sharp! Sharpen up your block plane after you buy it but before it is used. They generally come ground sort-of sharp but not nearly polished and not sharp enough. When you use your roller guide and stone, make sure not to tip the guide or the cutting edge.

Take a three or four foot straight edge and lay it across your frame from chine to chine. The straight edge should be resting on the outside of the ply wood sides. Plane the bottom of sides down until the the straight edge touches both logs and the frame all the way along the length of the straight edge. Sometimes the grain will catch and tear in one direction while it will cut smoothly in the opposite direction. Continue with your straight edge towards the stern. If your chine logs were properly beveled you shouldn't have to plane much at all except as you get closer the transom you will notice the bevel to chine log is less than 20 degrees.

Plane your transom bottom flush to chine logs and plywood sides, then take your hand saw and carefully cut off the bottom of your stem (which will be on on top as the boat is upside-down) flush to plywood sides at bow. Rather too shallow a cut than to have cut into the sides with your saw. If the bottom of stem is a bit high plane the end grain down to flush with chine logs, or use a wood rasp because planing end grain is an exercise in patience.

The goal is to get the bottom of sides and chine log into a flat plane from chine to chine following the rocker curve defined by the transom, frame, and stem all round the whole boat. You want your plywood bottom to fit nice and snug to the sides and chine logs.

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 Post subject: Cutting A Bottom for The Model F Special
PostPosted: Thu Oct 15, 2020 2:12 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
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Okay! If you can lay your straight edge anywhere on your chine perpendicular to the keel and parellel to the frame you can put your block plane away saftely on its side. If you lay it down on it's shoe you risk rust.

Take your 3'x8' sheet of plywood and lay it on the hull from the transom to whatever length is short of the stem. Secure your sheet to the chine logs dry with a few screws, just enough to hold it in place tight to rocker in the sides. Take a peek underneath the sheet to assure it is laying snug to logs. With an extra sharp pencil mark the outside of the sides around your hull. Also mark the end of sheet near bow stem with a mark on each chine.

Cut your bottom outside the line by about 1/4". I'd rather be ten feet to big than a hair's width too small. Take your 2' sheet and screw it down on your marks from the last sheet, factory edge of plywood on the marks. Scribe and cut the bow peice of your bottom a 1/4" bigger than your marks.

Now, there are a couple ways to join the two bottom sheet together. On The Model F Special #1 I just used a six inch rip of 1/4" plywood as a butt block on the inside, then ran runners port and starboard over the joint on the bottom of hull which along with the keel peice beneath the joint should be okay- until it starts to leak, which it will, because it is just a butt block. I don't recommend doing it the way I did. So with that in mind, here is how I Should have done it-with a magic trick-

Stay tuned and I will teach you how to pull a rabbet out of a butt block....

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 Post subject: Of Rabbets and Butt Joints
PostPosted: Thu Oct 15, 2020 5:25 pm 
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Posts: 10702
The thing about using a butt block on the bottom of a boat is that it is probably the second worst way to do it, with the absolute worst way being to stick the joint underneath the frame. On the Model F Special the frame is awful close to the butt joint in the sides and it would be really bad if a joint under the main structural brace for the hull fails. This is how come you need your bottom and side butt joints staggered, using a four foot sheet from the transom to the side, and and eight foot sheet from transom over the bottom. A butt joint in the bottom simply placed and glued in from chine to chine will tend to open up at the chine. The solution to this problem is to cut a pocket to tuck the butt block underneath the chine log. This pocket is called a rabbet.

To layout your rabbet first rip a 6" peice of plywood for the block and mark it's center along its length. Now, remember the edge of sheet marked on your chine logs? Place a mark offset center of joint (I like to mark these lines "C" for center and "0" for offset) half the width of your block, in this case 3". Place the block centered on the joint using the offset marks. With both ends hanging over, scribe a line along the outside of the hull on both sides of the butt block. These lines will be a very slight curve, but just cut it straight to simplify things. Cut one end. Using a scrap of 1/4" plywood and an extra sharp pencil, mark six inch long 1/4" offset from the inside bottom edge of chine log between your marks offset 3" from center, both sides of the boat. Now place your but block back on the chine marks with the cut end sitting on the 1/4" offset and mark the other side of your butt block, right over the 1/4" offset from inside edge of log. Cut that butt block out. You will now have a six inch wide butt block that is 1/2" too long to fit into its place between the chines. It will need to be let into the chine with an extra sharp utility knife.

To let your butt block in, use a 12" metal rule or straight edge and clamp it both sides to inside chine at exactly your butt block's thickness above top of bottom, 1/4". Adjust your knife so it can only cut about 1/4" deep. Holding the knife parallel to the bottom and NOT perpendicular to side of chine, cut between your 3" offsets. Then, again making sure the knife cannot cut too deep, carefully cut the bottom at the line bottom of chine log. After that, cut the ends of your rabbet out. Now a neat little stick 6" long and a 1/4 square will pop out. Place your butt block into the rabbet to check fit. The top of butt block must not be above the chine log. If the butt block is a hair low you might need to jamb a shim between block and chine when the bottom is glued, but if you REALLY screw it up it will need to be repaired with epoxy in which case you could just tape and epoxy the joint and forget the block. If your block is too tight, take material off the block, not off the chine.

Done!

Next, gluing and shaping the bottom.

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 Post subject: Building The Model F Special
PostPosted: Thu Oct 15, 2020 9:34 pm 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
The bottom of this boat will be glued with Pro Line Brand PL Premium polyurethane construction adhesive. Read the label before using. The screws should be 1-1/4" #6.

This is your last chance to check to see if frame is centered on keel, use your centers on transom and stem with a string line.

Put a good 5/16", maybe a 3/8" bead of PL Premium onto transom, frame, and sides right up to your rabbets. You will most likely need to spread the PL thinly all over the face of your butt block. Do Not put any glue in your rabbet, try to keep it out of there. Just lay the butt block in dry and cover the top of it. Set your aft sheet in place (use a helper) and using the same screw holes used to dry fit screw the sheet down. Screw every 6" staggered relative to chine screws in sides. Do Not do one side and then try to do the other, work your way from frame to transom. When you screw your bottom into the stern end of chines, make sure to stay about 6" forward of the back of the boat or you might split a chine. Do not screw center point of transom because the keel screw goes there. Just screw on each side of center.when you get to within 6" of your rabbet stop. First shoot a screw dead center middle of the three inches resting on the butt block. Don't worry about going through, but make sure it cinches up tight. Use a bigger screw if you need to, load it up with screws if you have to, but it must be tight to butt block. Then screw along the rabbet to within about 2" edge of sheet. Slap your second bottom peice on the bow ASAP. The first screw is put dead on center of keel middle of the 3" covering the butt joint. Then work your way from the rabbet to the bow.

After it is screwed and glued and before that PL Premium sets up you gotta crawl underneath and check your rabbets. When you get down there you should see a bit of PL Premium creeping out between chine log and bottom. If you got that all the way around I can tell you that it shouldn't leak a drop. Jamb two nails each side above edge of block right into the crack between rabbet and block. Six penny commons work best. If you need more than a 2" cut nail your gap is too big. Tap them in with a hammer. These are temporary so don't drive it in, just give the nail a love tap to snug everything up. Look for light peaking through in the sides. If you got gaps either force it down with screws or abort the mission and try to salvage your plywood to try it again later. Go back topside and check the gap in the butt joint. Using a putty knife force as much PL into the crack as you can. If you used factory edges both sides of butt then the sheets will be touching at the top of bottom edges but because it's on a curve the will be about a razor's width crack bottom of bottom and also in the sides opposite the side butt block. As long as you got the PL open might as well get those two.

Cork up the remainder of your PL with a bit of plastic bag wrapped around the nozzle with tape. You will still need it. Later you might have to punch a hole next to the nozzle, cut off the nozzle, or even cut the tube open and knife it out, but the stuff is still good. So save it.

While your bottom is curing up you will need to touch up your block plane.

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Just because government took control of one's actions does not absolve one from individual responsibility. Better to be in trouble with government than to commit evil.

In God We Trust.


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 Post subject: Re: Build a duck boat for a $ea-note?
PostPosted: Fri Oct 16, 2020 8:19 am 
Crown Grade

Joined: Tue Jan 08, 2008 10:15 am
Posts: 10702
Oh-oh. :?

I drew it out full scale last night and 1/4" rabbet won't be nearly deep enough into the chine to account for the flare in the sides. Might have to cut the bottom butt block a good 3/4" or maybe 1" longer than you need to fit between the chines, instead of only 1/2", and cut the rabbet wider.



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