Chuck Box / Wannagan Design Help, Please....

[LanceR]

Hello All

As background, I don't intend to be on any (or darn few) portages of any long distance. Most trips would be base camping (with day trips) and rarely more then 6-7 days in duration. And there will usually only be two of us.

I've been thinking about making a chuck box/wannagan for a bit and would appreciate any insights or advice. I've made a number of boxes for Boy Scout patrol boxes and family camping but as none of them had any risk of sitting in water I'm going back to the drawing board. Besides, the two we had left went to our kids when we downsized so now I have an excuse to try something new.

I'd kind of thinking along the lines of something loosely based on the BSA patrol box picture below, sized for a double canoe, with a more refined version of the adjustable height legs (running in aluminum c-channel) like the box in the second picture along with leg storage inside or under the box. I'm thinking of using either 3/8"/9mm or 1/4"/6mm Baltic birch plywood for the carcass and 1/4" for shelves and dividers. The rough weight of 1/4" Baltic birch plywood is 0.8 pounds per square foot and 3/8" is around 1.2 pounds per square foot so I suspect that once I have a drawing I'll figure out the approximate empty weight before deciding on which to use.





My target for the largest stove carried would be a two-burner Coleman liquid fuel stove although maybe I'd opt for the lighter flimsy modern ones if I have to carry this thing more than a few hundred yards. My Coleman (EDIT: changed from 425G to) 413G and 426C are great stoves but probably weigh twice as much as the soda can thin new ones and are much larger. The front flap and the top of the box would be available as work/cooking surfaces and the legs would get the stove to a comfortable height. Although I like using dish pans to hold things I'd put them on shelves instead of using them as suspended drawers as that leaves you nowhere to put the contents when you are using the dishpan. Add beveled cleats to the sides as handles (and maybe to attach a tumpline) and a pair of cleats under it to raise it bit off the floor of the canoe so it isn't always sitting in water.

So, that leads me to the big challenge; sealing the front flap to keep it watertight. After a lot of thought I am pretty sure that using an EPDM closed cell foam bulb seal (link below) would do the trick when pared with some adjustable latches (also linked below) on the side (and maybe the top edge) to pull the flap tight to the seal.

https://www.mcmaster.com/93085k12

https://www.mcmaster.com/1864a17


I'm a longtime finish and trim carpenter and sometime custom cabinet maker. I have no intentions of dovetailing this thing but for the most part, if I can imagine, it I can build it.

And now I'd appreciate your thoughts.


My thanks and best regards to all,


Lance

 

[alsg]

1. The drop front door/seal interface is only once place where water may get in. How will you seal the other joints? Are you going to consider glassing and epoxying the rest of the box to keep water from infiltrating the other seams and to strengthen the box -- especially if it is just 1/4" ply?

2. In considering the robustness needed for the seal, give consideration to how the box is likely to float in the event of a swim. Given the shape of the patrol box (taller/longer than it is wide), in the event the box goes for a swim, I think the empty box it is going to have a tendency either to flip onto its back (good because then the drop front/seal is above water) or onto its drop front/seal (bad). The location of the weight in the packed box may impact how the box floats in the water. Also, you could consider strategically adding flotation in certain areas to control the orientation when floating.

3. My home built cooler "NYETI" (Not a Yeti)) swam some class IIs by accident and had only a few tablespoons of water in it. The seal on NYETI is simple foam weather stripping in a channel; the thin edge of the lid is ratchet strapped down tight against it and compresses it. Of course, when NYETI swam and bounced off rocks, the top stayed upright and thus the seal was not severely tested. The building of NYETI including details of the top/seal interface, is shown in this thread. http://www.canoetripping.net/forums...cussions/diy/78638-building-a-tripping-cooler I'm sure you can come up with something even better.

 

[LanceR]

Thanks for the input. I saw your thread while doing my research. You did a nice job there.

I plan to use a long open time epoxy as adhesive and put in an interior cant strip to both reinforce the outside corners and to add a second epoxy joint as additional leakage insurance. Think of a stick of 1"square stock ripped diagonally and glued into the inside corners. That should be plenty strong and well sealed for anything that won't crush the whole box and will be watertight. As of now I don't plan to skin it with fiberglass cloth.

One concern I do have is whether 1/4" (or even 3/8" plywood?) is stiff enough to seal without any warping or bending. I could stiffen the perimiter of the flap or I'm pretty sure that I have a partial sheet of 1/2" Baltic birch plywood on the stock cart in the basement which would surely be stiff enough but at the cost of 0.8 pounds per square foot more than 1/4" stock for the flap. I need to let my brain cell dwell on that bit before ordering any material.

Best regards to all


Lance

 

[Odyssey]

That is the trade off. Light weight vs strength. I sought a compromise by going with 3/8" ply and rabbeting joints with screws and polyurethane glue. I didn't try for any waterproofing/floatation but did give it some thought. I elected to focus instead on the weight/strength/size conundrum, and hoped it would never see water. Ha. So far so good.
Looking forward to your project. I see a wooden lightweight, sealable, buoyant wanniagn as the Holy Grail of near traditional boxes. I am always interested in other approaches to this.

ps You now have me thinking about another build. Can a man have too many wannigans?

 

[BWCA66]

ps You now have me thinking about another build. Can a man have too many wannigans?

I'm assuming that is a retorical question........

 

[Canotrouge]

mine is made out of 1/4" ply with epoxy fillets on all meeting corners, so a total of 8 fillets! the bottom and the lid have a light cedar frame, this think is so strong that I can stand on it and I'm no light weight!! That box have been really tough and follows us on all sort of trips, canoe, snowshoe, truck, fly in, hunting, we climb on it, we sit on it.... One tough box!!
post #19 in this thread you can see a few pictures...http://www.canoetripping.net/forums...ions/diy/35861-the-waniggan-is-finished/page2

 

[Robin]

I have built a few out of 1/4 inch plywood with no warping on the lid, and my lid just sits on top, no latches. I did have one new lid that was warped from the get go so I replaced it right away, no problem.

I take mine with me when I go out with my small wall tent and use it for storage during the off season. Plenty strong, I can sit on it or even stand on it.

I have a video of the build which I have shared before but here's the link.

https://youtu.be/itlqp0btbpQ


.

 

[LanceR]

Thanks, Guys

I still need to ruminate some on just how much and just how I'd use this thing and what my priorities will be in the design. You thoughts have helped a lot.

I've worked with epoxy as a top coat, for smaller surface repairs and as an adhesive but haven't ever used it to fiberglass something or to build up a fillet. Would colloidal silica be the thickener of choice? And if mixed to mayonnaise or slightly thicker consistency do think it could be piped into place with a field expedient piping bag (heavy duty zipper lock bag) and then faired in?

Thanks again and best regards to all,


Lance

 

[alsg]

Thanks, Guys

I still need to ruminate some on just how much and just how I'd use this thing and what my priorities will be in the design. You thoughts have helped a lot.

I've worked with epoxy as a top coat, for smaller surface repairs and as an adhesive but haven't ever used it to fiberglass something or to build up a fillet. Would colloidal silica be the thickener of choice? And if mixed to mayonnaise or slightly thicker consistency do think it could be piped into place with a field expedient piping bag (heavy duty zipper lock bag) and then faired in?

Thanks again and best regards to all,


Lance

Yes to all of the above. You can also use wood flour, a/k/a sawdust to thicken the epoxy to make the fillets.

 

[LanceR]

Yes to all of the above. You can also use wood flour, a/k/a sawdust to thicken the epoxy to make the fillets.

If I do use epoxy fillets I had already planned to use some sanding dust with the thickener to better color match the epoxy, more out of a habit of wanting things to blend in than anything else I guess.... But if it can be done with all sanding dust I guess I'll check the dust bags on my belt sanders and see how much there is.

Lance

 

[Odyssey]

The 1/4" ply with epoxy is appealing. I'm thinking I may have overbuilt my boxes, especially when I pick them up. They're not beasts by any stretch of the imagination, but then neither am I. Building lighter looks good to me now.

 

[LanceR]

Building lighter looks good to me now.

That made me smile. Personally, I am several years down the trail to where things seem steeper, heavier and colder every year....

Best regards to all,


Lance

 

[Canotrouge]

I didn’t use fibreglass on mine and I don’t think it is necessary!!

 

[Boatman53]

Following along in this one. Here is an article from an old Popular Mechanics from the ‘50 I think it was.

depending on how you layout your shelves and dividers I think 1/4” would be fine.
Jim

 

[LanceR]

My thanks to all who have had or will have input.


My experience in building these is that the back legs can be vertical as there is no weight behind the box. That lets the box sit flush to tent and other walls and eliminates a tripping hazard. The vertical legs in the back also make it easy to lay the box on its back while fitting the legs. The front legs need to have enough slope to have the foot of the leg far enough to the front that a stove with a heavy pot or two doesn't tip the whole thing forward.

My thoughts on the aluminum side channels would be to close the top of the channels as a stop and use two small knobs on each leg threaded into a t-block that runs in the channel to be able to level the box on uneven ground. Something like this: https://www.amazon.com/gp/product/B0...WWF5G7JX&psc=1

Although it's not very elegant I have used 3/4" galvanized EMT steel electrical conduit in the past with wood dowel plugs in the top few inches and the bottom few inches to act as reinforcement for the knobs and a foot. Steel set-screw conduit connectors, not the zinc alloy ones, are strong enough to allow for two piece legs. The ones from greenhouse parts suppliers are particularly strong as they are thick walled for using EMT conduit in greenhouse erection. If you change the set-screws out with wing-screws it makes the job tool-less. I'm leaning toward having two piece legs stored under the box.

And I'm leaning toward 1/4" material for the sides and top with maybe a 3/8" bottom for the carcass of the box. The stove would on the bottom and at least one full width shelf above that along with a vertical center divider panel. Those two elements should provide ample rigidity to the front of the box to ensure a solid seal and provide ample structural strength. 1/4" stock won't give me much depth for rabbets or dados so I'll have to cleat or fillet the joints.

The next step seems to be piling up the stuff I expect to stow in the box and picking rough starting dimensions. I'll weigh that pile of stuff and add my best estimate for material and finish weights. Then I'll know whether I'm kidding myself and whether I need to pare my expectations down....

At any rate, we've lived here for nearly 2-1/2 years and I finally got around to painting the concrete block basement walls and putting up light duty pallet rack to get all the stuff off the floor. And I wired a dedicated new circuit for my rotary phase convertor as all my stationary tools are 3-phase and I had been unplugging the air compressor to use the phase convertor. I confess to being a wee bit exited that I finally have room to run big stock over or through my tablesaw, planer etc without have to move stuff first. My shop at our farm was a 5800 square foot steel building and downsizing to a basement, even a nice dry and large basement has been a bit of a journey in itself.

Since I plan on using an epoxy top coat to seal and protect the wood it seems to make sense to top coat the plywood before cutting to avoid having to finish coat the interior after assembly. Any thoughts?

Best regards to all,


Lance

 

[Boatman53]

I agree at least pre coat the ply that will be on the inside. Now if only the legs could fit inside.
Jim

 

[Sweetfancymoses]

I came across this design a while back. I haven't built them though.

 

[LanceR]

Boatman, I've built or seen these with the legs inside, on the back, underneath and loose. Obviously loose is out and on the back is out if I want to tote it with a tumpline, pack harness or packboard. And inside means that the I'll be using space that, for me anyway, is better left to other things. As the bottom of the box will have cleats under it for stiffening, to better fit a canoe floor and to raise it a bit from any water in the hull, the space between the cleats seems to be be ideal for the legs.

sweetfancymoses, I've seen different variations of that allowing the legs to be used as carry handle before. In my case I don't need the carry handles and it doesn't allow for leveling the box.

Best regards to all,


Lance

 

[RickR]

[No message]

 

[alsg]

Wow! Great Gilpatrick style boxes!