Aussie Cackler 14 build

[Matthias]

G’day, I’m Matthias, live in Sydney Australia and I’m building the Devlin designed Cackler 14.

Backstory
Why am I building a duck boat? Briefly: used to live in Mildura, which is roughly halfway down the Murray River, Australia’s longest river and wanted a custom camping and river exploring boat. Devlin’s Honker 18 seemed like the ticket so I bought the plans and got ready to build. Life changed, moved to Sydney, build plans and desire ceased. Fast forward to January 2025 when with a group of mates I signed up for an event called The Tinny Rally. I don’t own a boat so instead of buying one thought it would be cool to build one instead and revive the Honker build dream. But Honker’s size is a tad large for the Rally, so decided to build its smaller sibling instead.

I’m building the boat at work (small signage and display business) which is good because there are heaps of tools, but also bad because our factory is tiny and there is no dedicated space available to build, so sometimes the boat hangs from the ceiling, sometimes it’s on trestles and sometimes it’s just lying on the ground.
I did contemplate buying a CNC cut aluminium boat kit and welding that, but even though I’m not a woodworker a plywood build seemed easier and more fun. So here we are…

The pic below is the current build state, but I’ll post retrospective pics so you can see how I got to this point.

 

[RM Anderson]

Mathias,
Glad to make your acquaintance. I am also considering the Cackler as a general fishing and duck hunting boat. The Cackler, for some reason, just speaks to me. Number one, I'm not getting any younger so another layout boat for hunting doesn't seem reasonable. Number two, I really miss my fishing boat after selling it this summer. Some people think the Cackler is a little cramped for three hunters and a dog but I figured if I went with a traditional transom it would free up some space and eliminate any outboard fitment issues.
I saw your original question on Henry's thread and just have to ask why wouldn't you glass the floor in? To my way of thinking you have nothing to lose and everything to gain. Epoxy is strongest when used as a composite. Looking forward to following your thread with great anticipation.
RM

 

[HenryHawthorne]

I saw your original question on Henry's thread and just have to ask why wouldn't you glass the floor in? To my way of thinking you have nothing to lose and everything to gain

RM - interested in your thoughts on this, as I've been leaning otherwise.

My thinking is first influenced by the fact that bonding the floor to the hull is optional. I'm bonding mine since it does add some strength and rigidity to the boat. Second, given tapers on the outer edges, I (and it sounds like Matthias, as well) will have 4-6 inches of sole in direct contact with the hull bottom, with thickened epoxy in between and a fillet and coat of epoxy above. Do you think tape will add measurabley to the strength of the wood/epoxy/wood/epoxy scarf-like joint?

The downside of glassing the joints, to me, is just the time and material required, and the weight of tape plus a few extra coats of epoxy to wet and fill it. Not major costs, obviously, but it seems like the benefit would be minimal. I'm open to having my mind changed.

 

[RM Anderson]

RM - interested in your thoughts on this, as I've been leaning otherwise.

My thinking is first influenced by the fact that bonding the floor to the hull is optional. I'm bonding mine since it does add some strength and rigidity to the boat. Second, given tapers on the outer edges, I (and it sounds like Matthias, as well) will have 4-6 inches of sole in direct contact with the hull bottom, with thickened epoxy in between and a fillet and coat of epoxy above. Do you think tape will add measurabley to the strength of the wood/epoxy/wood/epoxy scarf-like joint?

The downside of glassing the joints, to me, is just the time and material required, and the weight of tape plus a few extra coats of epoxy to wet and fill it. Not major costs, obviously, but it seems like the benefit would be minimal. I'm open to having my mind changed.

Henry and Mathias,
Not bonding the sole to the hull is certainly optional but I am not sure it is the best practice. I could be persuaded not to bond the sole on a human powered craft, but even the Devlin Poleboat which I built was stiffened to such a degree, I became an instant advocate. Glassing the sole/hull joint makes good sense to me when you consider the forces that a motorized boat hull will endure in rough seas. Those forces will be transfered upward from the hull to the sole. For that reason, I consider the sole a supporting member that should not only be bonded to the hull but also glassed in for additional reinforcement. Just my humble opinion, RM

 

[Matthias]

Henry and Mathias,
Not bonding the sole to the hull is certainly optional but I am not sure it is the best practice. I could be persuaded not to bond the sole on a human powered craft, but even the Devlin Poleboat which I built was stiffened to such a degree, I became an instant advocate. Glassing the sole/hull joint makes good sense to me when you consider the forces that a motorized boat hull will endure in rough seas. Those forces will be transfered upward from the hull to the sole. For that reason, I consider the sole a supporting member that should not only be bonded to the hull but also glassed in for additional reinforcement. Just my humble opinion, RM

Hi RM and thanks for your input.

I asked the question because I don’t have the building experience or knowledge to make the right decision. Unfortunately the Cackler plans give no detail about sole treatment. But the Honker plans state that floor is removable and fastened to the keelson/stringers with screws and bedding compound which made me wonder if glass taping the port and starboard floor sheet edges is necessary, especially since I’ve epoxy glued all edges and onto keelsons/stringers. I’ve even added two extra stringers to the aft floor section because I didn’t want to ply to bow when walked on.

I’ll post some pictures tomorrow so you can see how I’ve modified my boat from Sam’s plans. I think the Cackler is decent enough in size for 2 people and a dog. Especially if you modify the rear transom section. I’ve opened up my boat more by narrowing the decks port and starboard and deleting half of the front deck. Tha front storage compartment is now open boat in my build.

PS. I do plan to glass tape all for and aft edges of the floor sections.

 

[Matthias]

RM - interested in your thoughts on this, as I've been leaning otherwise.

My thinking is first influenced by the fact that bonding the floor to the hull is optional. I'm bonding mine since it does add some strength and rigidity to the boat. Second, given tapers on the outer edges, I (and it sounds like Matthias, as well) will have 4-6 inches of sole in direct contact with the hull bottom, with thickened epoxy in between and a fillet and coat of epoxy above. Do you think tape will add measurabley to the strength of the wood/epoxy/wood/epoxy scarf-like joint?

The downside of glassing the joints, to me, is just the time and material required, and the weight of tape plus a few extra coats of epoxy to wet and fill it. Not major costs, obviously, but it seems like the benefit would be minimal. I'm open to having my mind changed.

Yep Henry, that’s pretty much my thinking as well. And the thing is, that atm the sole/side edges are so sharp, straight and lean that it would be a shame to wreck them with a fillet and glass tape

 

[RM Anderson]

Matthias,
Sam Devlin's plans are never really clear and are open to alot of interpretation. If you look at your attached hull crossection you will see two triangles. A triangle is one of the strongest structural shapes, albeit in this case a scalene triangle. Its like a free gift, so yes, I'm glassing that floor in. I would wager a disproportionate number of boat repair theads have removable soles. That said, my theory is mine alone and I'm not going to be offended if everyone doesn't share it. You are correct about the amount of work it takes to make that tape line disappear. Maybe your idea is the best of both worlds. However you are persuaded, I say run with it! RM

 

[Eric Patterson]

Many years ago Sam came on the forum and presented a drawing of how he likes to see floorboards done. I have looked all over and can't find the picture. Can't say for sure but I recall he suggested bonding them on all sides and down the keel timber. My preference is just that with both sides glassed. 1/2" ply isn't the most rigid floor and could use some stiffening.

 

[HenryHawthorne]

Thanks RM and Eric. Will reconsider when I get to that point.

 

[Matthias]

Thanks for the insight Eric and RM.
I’m gonna go for it. But I’m only doing one layer.