Design question - 'glass or stitch-n-glue?

Steve Sanford

Steve Sanford

Well-known member
Mark Johnson (another duckboats.net member) and I are in the early stages of designing a lightweight duckboat to serve a variety of purposes. We want a lightweight vessel - for oar or double-paddle - that can serve as a grassboat or a layout (in a pinch). It needs to ride on a roofrack - and be handled off and on by 60-year-olds.

We are inspired by the Carsten's Pintail but want more crown to the deck and a smaller cockpit. LOA is 13'6" and beam is 42". Total depth of boat ~14 inches.

Here are 2 views of our model (1/6 scale):

Cartoppermodel2-sm_zpsff496fe2.jpg


Cartoppermodel1-sm_zps47a20a39.jpg


NOTE: The molds in the photos are just for modeling purposes - so we could envision the shape we want. There will probably be a bulkhead fore and aft of the cockpit - and floor frames ONLY if we need them. The hull is generally U-shaped in section and we will add stringers or strakes to stiffen it longitudinally as needed.

Here are our questions:

1. IF we build it stitch-n-glue, we were thinking 6mm for the hull - sheathed with 6 or 7oz 'glass cloth for wear, etc. Probably go lighter with both plywood and 'glass on decks.

2. IF we mold it out of 'glass, will 2 layers of 17-oz double bias with mat be strong/stiff enough? Will 1-layer be enough for the deck?

With either technology, we will probably reinforce the "floorboard" area.

Thanks for your thoughts,

SJS
 
In stitch and glue, I wouldn't even attempt a complex design like that from scratch (I know that isn't much fun). It can be done, just not my me at this point in my life for one boat.

Devlin's book he tells how to design stitch and glue boats. :). Has a nice long section on it.
 
Steve,
It appears that you will have several compound curves. I suggest that a cedar strip build might be your best choice for light weight and ease of build.
 
Steve,
It appears that you will have several compound curves. I suggest that a cedar strip build might be your best choice for light weight and ease of build.
Click to expand...

I agree. Plus it will be so purdy before you paint over it!
 
To me that boat's lines would be well suited for bead and cove construction. You can keep the weight down, the interior uncluttered, and still work with wood.
 
If, you go with cedar strip, use 2 layers of 6 oz. cloth on the outside. One layer is NOT enough for hunting. Nothing worse than seeing you hard work ruined before your eyes one small bump and ding at a time. Don't ask me how I know.
 
Eric et al~

We were avoiding strip built because of the time - and because we might make a total of 4 or so boats.

Our approach with stitch-n-glue would be to experiment with a piece of 1/4" lauan over the moulds to see if we can "torture" the shape on the bow and stern; the 3 middle stations are essentially the same. I'm familiar with the conventional "conical projections" limitations of heavier panels but - these compound curves work on the scale model with heavy paper and I think we could get very close with plywood.

If we go with all 'glass, we were considering a "strip built" male-mould made from foam boards faired with joint compound (an old method for one-off hull construction).

Maybe the best approach is to build the first one strip-built cedar - and then mould subsequent hulls from it....

Too many boats....too little time....

Thanks for your thoughts,

SJS
 
I experimented with 4mm okoume plywood when building my own version of a Hybrid Duck Boat. I did manage to torture the front deck down to a couple of compound curves on the bow section. Some of the hybrid boat builders over on the Refuge have put some decent curves into their bows without knowing anything about boat building. Some look horrible and others came out decent and functional.

The only issue for the 4mm is that is stays really flexible until you put several layers of glass on it inside and out. You then loose all the weight savings.

If I was going to do the small boat build again, it will be one of three cores: cedar strip, top shelf boat foam core, or plastcore honeycomb.

You can also look into birch underlayment for an experimental material. It may not bend as well as luan.

I have a 70/60's era canoe building book out of Egland. They built a rough wood latice strip structure on frames, then faired it with drywall joint compound, then coated it with about 1/8 inch of bees wax waste from a bee keeper. On that male mold they built a kevlar canoe. Pretty sweet process until it takes several people to pull the hull off the mold without cracking along the keel. The bow and stern were unfinished to allow for the hole hull to be spread.
 
That looks like a really neat boat, I think that if you are going to produce more than 2 or so then molded glass might be the way to go. Or you could go high tech and use something like Airex-I know that it can make some nice compound curves. I'm looking forward to seeing what you guys come up with!
 
Steve,

If you do a search for IB duck boats in the old posts, you'll find the original boat that Ira and Ben Gallup first built. It's pretty much exactly the same length but a bit narrower (~38") than what you are shooting for. It's not a double-ender. They built a mold and used woven roving (I don't remember the weight) along with a couple layers of CSM on the hull. Their angular design provides structural support for the deck. It probably weighs about 50-60 lbs (a guess) I can carry it on my shoulder pretty easily and it's nothing at all to drag it across grass. Here's a picture:

bengallup8.jpg


I built a different mold/boat that is wider (same width as the KARA), but the same length. It's quite a bit heavier (more in the 80-90 range). I used the same design ideas with angles to provide structural support. I essentially built a KARA for the plug (but modified the stern to be flat) and then built the mold from that...it's a longer process, but the results are exactly what I was looking for, and once you have the mold, you can knock out a new boat in a couple of days. We've made about 10 of these over the years. Here's a pic of mine when we first put it in the water (yikes, that was a decade ago now!):

View attachment 21728

Ben's boat will hide in the smallest of cover compared to mine, but the extra width makes the boat MUCH more stable and is the reason I made a different design

Like any duck hunters, we beat these boats up quite a bit and they are very sturdy. I haven't heard of any problems from those that have one after a decade of use.
 
Looks quite a bit like my Hoefgen. 15' LOA, 62 lbs, curved decks.

On thing I can pass on. A 60 year old guy will not be able to car top the Hoefgen. It is not the weight, it is how the weight is distributed. A 60lb canoe can easily be lifted onto the top of a vehicle as you can grab the gunnels and lift over your head. With the Hoefgen, the deck is also on the sides so you can't grab the outside gunnels to lift over your head. You have to grab inside the cockpit which makes the weight very awkward to manage. I gave up on cartopping my boat because of this. Plus the fact that I am a 200 +lb wekaling.

Something to consider.

Mark W

http://www.hoefgencanoes.com/duckboat.html
 
Last edited:
Car topping made tolerable. Mark, I can't remember what rig your driving, but the roller style kayak rack made topping my scull very do-able and it weighs considerably more than the Hoefgen. The key is you only have to lift the bow up onto the rollers then pick the stern up and push the boat forward onto the vehicle. I even used the rack to bring my sneakbox up from NJ to avoid dealing with a trailer. Definitely overloaded the rack but for one 4 hr drive thru NY & over the GW bridge it was worth it !

View attachment car topped.jpg

View attachment from the rear topped.jpg

Scott
 
Steve its really been enjoyable reading your posts here and on your website. It really brings back good memories and is nice to see some familiar faces from the South Shore Waterfowlers. I have to start uploading some digital pics of my modest projects so I can really participate in the discussion. That boat design if you could keep it light enough would serve double duty as a freshwater boat and up on the flats in the saltmarsh if you could transport it with a motor boat there. Remember the last time we hunted together out of Pt. Lookout? You had that converted sunfish type to layout boat that you double paddled once we towed it there. I'm rehabbing my 14' delhi open fiberglass and outboard and envision being able to tow a similar boat and a couple of Sanford boxes to those type spots and set up and anchor the motor boat back at the channel. This way you could hunt through the tides without worrying about going high and dry and could paddle or pole out in an inch or two of water in the double ender as needed. I just love the way the black ducks decoy in at a spot like that given the right conditions. I have the motor boat prepped and painted again and have to rebuild the carb at least for the outboard. The trailer is redone with new wheels tire ,hubs,bearings and coated but I'm struggling with the light bar. Also I'm struggling with the State to get the boat I had registered for a good part of over thirty years I owned it and they won't re-register it because they don't like the hull ID #s from my old registration and I've since covered up the ID tag with the transom raise mod.
Once I get the boat operational the next step is working on some Sanford boxes as the ones we made have long since delaminated and I lament the fact that I never stored them properly in the off season. After that a boat design like your proposing could be next. Maybe a trip to the Sanford boat yard could be arranged as I live in Sullivan County now so its not that far. I really love the look and tradition of a Barnegat or similar but I figure I should work with what I have first. I never thought the Delhi was a good candidate for a boat blind because of the 48" beam and would lose the utility value of the open design. I hunt mostly freshwater now and use a 14" sporspal canoe which I absolutely love. super wide and stable.
I saw on your website some pics of your U.&L. lakes hunts. I really want to start expanding my horizons North and increasing my waterfowling adventures and was looking at U.&L. lakes and Perch River as well as some Western zone opportunities. Maybe you can PM me if you have any usefull info about hunting there to point me in the right direction. Thanks, Pete.
 
Last edited:
Pete~

I am looking forward to you breaking through the digital camera/posting photos barrier!

Your thoughts about the cartopper serving as both a freshwater vessel and a towable/rowable on the saltmarsh are my thoughts exactly - and, yes, inspired by that little Minifish conversion I hunted from with you guys lo' these many years ago. I am thinking I can tow only one boat at a time - from here to LI - and it will probably be my Ice Scooter. But, I could have a smaller craft up on the roof racks on the same trip.

re Upper & Lower Lakes. I have not hunted it in years - it was overrun with roboducks the last time. I might consider going up for the second opener because there are many fewer gunners - but the date is usually the same as the LI Duckboat Show.....

All the best,

SJS
 
For a completely different direction give some thought to a Old Town Pack Canoe. They weigh less than 40 pounds.
As built, short & in normal "canoe" mode (with the weight way too high) they are an accident waiting to happen. Taking out the seat, sitting on a cushion & using them with a double paddle they have ample room for decoys (unlike sit-in kayaks) and are very handy.
Mine was green with a light interior. I attacked mine with rattle can plastic paint & painted the interior black.
I got mine used for 200 bucks (I assume because it was an accident waiting to happen).
I did something similar with a 15' old aluminum canoe that I stashed in one of my walk in small creek spots. Took out the seats, painted the whole thing with Parks duck boat green & I typically use it kneeling on a cushion with a double paddle.
 
Car topping made tolerable. Mark, I can't remember what rig your driving, but the roller style kayak rack made topping my scull very do-able and it weighs considerably more than the Hoefgen. The key is you only have to lift the bow up onto the rollers then pick the stern up and push the boat forward onto the vehicle. I even used the rack to bring my sneakbox up from NJ to avoid dealing with a trailer. Definitely overloaded the rack but for one 4 hr drive thru NY & over the GW bridge it was worth it !

Scott
Click to expand...


I had an old Dodge Dakota quad cab so getting the boat up to the cab part was impossible. I used a fulton canoe caddy for awhile but it was cumbersome.

I now own a Jeep Grand Cherokee. I started looking at car topping on this vehicle but the rails that came with the vehicle (the ones running parallel to the vehicle) would not allow enough space between crossbars should I mount them. Sort of a dangerous situation. I went out and found a Yakima Rack and Roll trailer and use that now.

Mark W
 
Gary~

Thanks for your thoughts.

The driving force behind the new (proposed?) vessel is the wider beam - ~ 42" compared with the 35-36" of the typical canoe. This is my Sweet Gherkin - I molded the hull from a 13' Grumman and then decked it over. It is great for protected waters but I would not trust it on the open expanses I hunt on Great South Bay. Any new vessel would look something like this - but with wider beam for stability and lower ends for a better hide and to reduce windage. And, since my 2 artificial knees do not like me to kneel anymore, I will row or double-paddle it from a low (5" tall) stool.

SweetGherkin-2010vs_zps27e25700.jpg


This is the converted Minifish that Pete referred to in his note. Minifish is a smaller cousin to the Sunfish.

McFeelyLayout-cropped-sm_zpsa0fbb4de.jpg


If I found and converted another hull, I would remove the decks entirely and put more crown in new decks. Nevertheless, it does work well as both a layout on open water and a grassboat up inside the marshes. And, both Minifish and Sunfish hulls row very well.

The design process itself is a source of great enjoyment for me. Or maybe it's an illness - I have yet to build a boat to existing plans...

And, of course, a friend stopped by the other day and suggested still another technology - cold-molding. I always enjoy learning new methods and now I need to find a source for the veneers.

All the best,

SJS
 
Steve

I'd expect a big difference in stability sitting on a cushion & a 5" stool.
My aluminum canoe is a 15 michicraft and has "sort of" hard chines but it is still "tippy" in canoe mode. A friend gave me a 16 klickaclack (sic?) & I considered cutting it way down to lower the profile but it was wicked heavy, had round chines & was too tippy to fool with & I gave it away.
The most stable small boat in my fleet is an old 16 Sportspal (which has oarlocks!!!). Also very light but it's aluminum construction & foam lining (that makes it impossible to completely rinse out) dissuades me from using it in salt water. The sponsons add 6" to the 38" beam and it has round chines but the bottom is very very flat.
If I could score a Grumman lightweight aluminum canoe I wonder if foam sponsons would be the stability answer.
 
Gary~

Here is the stool we use in my Scooter - which has a beam of 44".

smGear6_zpsb33d287a.jpg


It doubles as the headrest. It makes all the difference for me when rowing, tending the rig, etc. I have always had really tight hamstrings and cannot row sitting flat on the floor. In fact, I tried that in my friend's Carsten Pintail in January - not an experience I want to repeat.

All the best,

SJS
 
You must log in or register to reply here.
Back
Top