1652 Hunt Deck Build

Well... my thoughts... really are only based on scarfing.... Or having ALOT of peanut butter and tap on a V.....
I guess.. I would be very nervous about trusting my life to butt joints... perhaps it is a proven method... and if it works.... then I am VERY confident in my boats....


I will be curious what those with more experience think....
 
Thanks for your reply...

The fiberglass tab/butt joint covered with the main hull fiberglass comes from me following a lot of builds on another web site. My only practical experience is with a 14' pirogue I built about 10 years ago. It was wood butt joints on the interior and one layer of glass on the hull. Here it is 3 years ago, failing structurally but watertight and safe enough to use in shallow water:


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Here it is, this year after 3 years on the bank, spending 7-9 months/year submerged. The fiberglass hull is intact and holding a large weight of water against its shape.

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This is somewhat anecdotal and not meant to prove anything definitively, but the glass is pretty amazing. I would love to hear from others, especially anyone who has experince with failed joints of any type.
 
Phil and Brandon,

The boat building and plan selling company of which I consider myself a customer advocates using butt joints (a plywood piece glued [wood flour/epoxy peanut butter] and spanning the joint) or fiberglass splices (like I am using) to join the long panels. The strength of the hull that they advocate comes from the plywood being sandwiched between the fiberglass both inside and outside the hull and the filleting (peanut butter) and taping at the chines as well as where the interior frames (bulkheads) meet the hull at the sides and floor, with additional beefing up the motor well and transom.

The main technical differences with what I am doing and what they advocate is they are using 12 oz. tape and I am using 8.7 oz.; and I am using exterior B/C ply instead of marine ply. My splices are not planned to fall on frames; I may need to adjust my floor plan or plan on "open" frames to help support the joints.

I will use two layers of 6 oz glass on the exterior and at least one layer of glass on the inside. If I really worry about the joints after considering everyone's experiences I may use 3 layers of glass. The sole will help stiffen the hull and support the joints as will the interior and exterior gunwales (inwales?)

It's worth noting that I don't plan on running offshore hunting surf scoters or Eiders (or whatever grand waterfowl brave the salty spray of the Seaboard....incidentally, a hunt of which is on my bucket list) but many of the boats that this company designs are used in such conditions.

Thanks for sharing your experience, please keep the insights coming.

- Jeffrey
 
Contemplating The Big Flip.

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I sat probably 20-30 minutes trying to figure how to do this, working by myself. After bracing, I put a 2x4 under the midship area and it supported it perfectly. The lower panel in the photo is the side panel.

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I put in a stop block to keep it from sliding as I lifted it.

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Up to the top... (Yes, shorts. Dec. 22, and it's 70 degrees. Another reason I wanted to get this flipped and taped while the temperature was right before the front comes through tomorrow.)

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Success!

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Moving forward...

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Two hours later.

My wetting out technique has really improved. I was able to make 18 oz of mixed epoxy wet out about 24 linear feet of tape. We'll see if any delaminated tomorrow. The pavers/weights are probably overkill but I wanted the joints to be flat...you're looking at the inside of the floor. If it was bowed any I would have to fair/sand forever in order to get the last 4-6 feet of the full perfectly flat.

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As long as you are using a backer on the joints you should not have any problems. By backer, I mean another piece of wood over the top of the joint that is applied with epoxy and wood flour mix to glue the pieces together then the outside has a fillet all around it and then that is covered with tape and glass. You are looking for a hull failure the way you are doing it. There is not much strength at all the way you are doing this for the joints.

Please rethink the way you are joining these panels.
 
This looks like the Bateau boats way.
Thin plywood core sandwiched between heavy glass 12oz or heavier inside and out? Seam tape is heavy also. I think the thought is you end up with a fiberglass hull.
Devlin boats way, heavier plywood lighter glass
Which one is better? Time will answer that question.
 
Jeffrey, take two leftover scraps of plywood, 6 inches by 24 inches will do. Butt the 6 inch ends together, glue and glass in the same manner as you did your bottom planking. Wait a day or two for it to set up well, you should now have a 6 inch by 48 inch piece of plywood. Now set the piece on two saw horses. Next press down on the middle and see where it breaks. Maybe even offset the joint to give it the benefit of the doubt. The joint should be at least as strong as the rest of the plywood, a little stronger would be better. If it breaks at the joint, make up another sample with more glass, until it breaks on one side or the other of the joint. This should tell you how strong to make those joints. I build boats for a living. If you think something is strong enough, better make it twice as strong! Rich
 
I like that idea Rich!

I would be leery of butt joined plywood without a backing plate or rib across the whole length of the joint. I screwed and glued my transom at one floor joint and a large rib across the other. There is a surprising amount of flex with a ply / epoxy boat.
 
I would use the backing plate idea on butt joints. Not enough strength with the butt joint even on a rib. Local garveys were butt jointed with a LARGE backer of ply screwed and epoxied. I use alot of West System on gun stocks, boats and ice boats. Worth the extra expense. Labor is the big part...
Project looks great, can't wait for more pics...
 
I hope everyone had a Merry Christmas. Thank you all for your encouragement and sharing your experience, most of all for your consensus about the strength of the fiberglass splices that I am using. I haven't done much until yesterday, partly due to the holidays, but mostly because I needed time to think.

I hadn't planned on this build thread becoming a Devlin vs. Bateau debate...both systems have their merits and practitioners. I know that there are plenty of Devlin builders and believers here and I am thankful for your input. This is not a Bateau design, let me stress, but mine. I do believe in the plywood/glass sandwich that they design with. I would love to hear from someone with direct experience in both boatbuilding systems and the pros and cons of each.

Both systems are just that: a system. A system for dealing with the stresses put on a hull due to moving through and being acted on by water unequally at different strengths, at different points and angles, and at different times without failing. Longevity and utility are also desired results of the system. It was a bit naive on my part to think I could throw something together when engineers spend long hours designing how to deal with expected stresses on a hull for a given speed, horsepower, and program. Everything contributes to the system that results in hull strength, from flat seam joinery, to tape weight/width, fillet size, hull glass weight and layers, frame location, etc. For reasons I won't get into, I expected that the splices I am using would hold it together for construction and that the necessary strength would come from the inner and outer hull glassing along with some of the other framing aspects I mentioned above. This may or may not be true, but I don't have the tools to predict either way with certainty.

The end result of this research on my part is that I will err on the side of caution and build to the high end of the spectrum of safety with the hull joints:

1. Every seam will be backed up by plywood glued, filleted and glassed spanning the joint.
2. All tape will be 12 oz biax.
3. This will be backed up by framing; stringers and sole for the bottom, open frames 4 inches wide on either side of the side panels.
4. The outer hull will sheathed with two layers of 12 oz biax, 50" wide overlapping at the centerline and extending to the gunwales. Perhaps even a layer of 5 oz Kevlar. The inner will receive one layer or glass.

Please keep your insights coming as I move forward, and a special thanks to everyone who contributed to this plan for ensuring hull integrity.
 
Yesterday's weather was nasty here in Louisiana. We had another Pacific front move slowly through...it's still moving through today. But yesterday was 68 degrees whereas today it's topping out at about 50.

I have yet to order my wood flour because I wanted to make one order and I hadn't solved my tape type and weight questions until this weekend. So I haven't been able to glue up the stringers to use to locate and mount the frames using the Sharpie method. However, I need to put the hull together temporarily to finalize the shape of the forward frames (the frames in the rear, box part of the boat all have the same shape.) So I decided to use basically a 2x4 strongback to accomplish this.

First I laid out the frame locations. I will have a rear deck, a midship seat, and a deck at the bow. I will also have the open frames supporting the two side panel splices.

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I then put together the strongback. I had to notch it for the frames to fit over it.

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Support for the frames made from wobbly 3/8 ply.

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Frames going up as the fog starts to roll in. For a while I amused myself imagining I was building in a shop on the coast in a foggy lobster town. Seriously, the delirium that sets in during a seven hour session.

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Here's a preview of the shape.

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Neither fair nor square at this point, I've got some geometry issues to work out before I can draw out the frames. I really wish I had used 3/8 instead of 1/4 for the sides. I'll probably have to laminate on the gunwales to stiffen and fair the hull shape before taping/flipping.

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On another note, a reminder of why we do this: my son killed his first duck this week. Jumped him up from a hardwood bottom creek and shot him on the wing.

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Jeffery, your plan sounds a lot more sound, better to overengineer the boat than under engineer it! You can always get a bigger motor, Rich
 


This is the bottom of one of the boats I built. I added a piece of ply on the inside that was bedded in 3m 5200 then screwed to the bottom. Don't have a pic of the inside of this. I then filled the gap with epoxy and wood flour mix. I went over and sanded this 2 times to make sure it was filled and flat. I then laid two layers of 10 oz fiberglass over the entire bottom.



Here it is finished. I laid glass on every surface of the boat. We will see how that works out.

Here is how the inside is laid out.



Just make sure the bottom is absolutely flat and you do not end up with a hook in it. Ask me how I know this?
 
Thanks Rich, and great looking boat, Tom. Did you just live with the hook or did you work it out while building?

Not much to report today, still working on shaping the bow and cutting the two forward frames: the bow transom and the front deck frame. First, I leveled my strongback 2x4 frame...the hazards of cheap materials: I had to level due to the bottom bowing and making one side higher. Here I am with wedges driven under the port side. I can't wait the fair the bottom of this puppy. I should have removed the hull bottom from the table, but with the rain coming I didn't really have a good place to store it.

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Working on the bow shape. The bottom width is determined already at known distances from the rear transom. Find a distance from the transom on the bottom, measure the width of the bottom, find that same distance from the transom along the bottom of the side panel, and secure a spreader cut to the bottom width at that point. This will mimic the shape of the hull bottom along the side panel. Just to the rear of the side panel splices, you can see where I secured the sides and the bottom together with screws in blocks.

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Here you can see how the bottom width narrows from 52 to 31 inches. Better to nose through the trees. The clamps are rigged in this picture to draw in the top of the side panel at the bow in order to fair the toplines. The flare on the sides of the hull inverts a couple of feet behind the bow...the hull bottom is actually wider than the top at the bow.

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You can see a little of it in the model.

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After I get these frames cut out, I will take her apart and butt block the seams, alter the frames for the butt blocks to pass under them, and then put her back together with the stringers, square and tape the corners and try to figure out how I'm gonna flip this hulk.
 
I flipped it over and sanded off all the paint. Then leveled off the bottom as well as I could. Then layered glass in the middle where it was the worst to fill it up. Sanded smooth. Then poured a thin mix of epoxy and silica so it leveled out the bottom. Had to do this a couple times to get it all the way to the edges of the boat. And to the front far enough to be able to feather it out very far. You also have to make sure to not create a bowing effect. A LOT of sanding. And using a 3' sander.

If I can offer a little more help right now before you start to really screw this together. Figure out how this is going to drain water right now. Look at every little area of the boat and how it will hold water.
 
Tom, what do think about limber holes in every compartment that will allow water to run along the sole. One at each chine so it will drain when not level, which is most of the time...both on the water and on the trailer. The sole at the rear deck will have limber holes that will pipe the water into the bilge. The bilge is the lowest point in the hull, as everywhere else is sole level or higher (like the bow compartment.) In the bilge, I'll put a pump on a manual switch and a slightly higer elevation and higher volume pump on an automatic switch to help pump out with downpours. I don't want rain to keep my from running to the duck blind.

Do you have an opinion on whether or not I should plan for eventual water accumulation below the sole and allow it to drain to the bilge? Such as cutting limber holes in the frames where they meet the hull?

Also, how did you brace for your pedestal seats?

Thanks, - Jeffrey
 
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