Waterproof, Durable Boat Boxes: the Pragmatics, Doubts, and Worldview




Introduction: Waterproof, Durable Boat Boxes: the Pragmatics, Doubts, and Worldview

About: If you read blogs, come vist mine: www.tristramshandy21st. blogspot.com where right now I am posting chapters of my humorous and philosophical nonfiction, "In Search of Tim Severin" among other things.

(Revised 4/23/07: shortened).

Here are two waterproof boat boxes to store emergency gear and regular gear. Boat boxes are good for protecting crushable gear from tsunamis or your stupid feet. I love flexible waterproof bags and have several, but for the delicate expensive stuff, the box works for me. The photo shows the gear that goes in the large box, minus a flashlight, because I am between flashlights and am seeking a good bright LED one I can afford.

Design Worldview comments:

(1) Bags are good, but Boxes are more Multifunctional -- Boxes can double as hasty stools. I love multifunctionality. Modification: either box could incorprate a small closed-cell foam pad, with nylon cover, to make these boxes into gear-and-tired-butt boxes (not to mention add flotation power).

(2) Weight and Buoyancy -- These boxes are rather heavy (big one is pine, epoxy coatings in and out, fiberglas cloth as abrasion protection, then paint. However, the weight is mostly from thick wood, which floats. You can build them lighter without sacrificing much strength. Thus, the small box is marine plywood on four sides epoxied to pine squares at the ends, so it is lighter.

Closed cell foam used to pad the interior also provides floatation. The boxes float when sealed, but what if you capsize right after you open them? Well, good luck! You can't design around all the issues. More closed-cell foam to insure flotation (the boxes hold some heavy stuff after all, such as tool kit, radio, and flashlight); more foam means less carrying space inside, means larger box needed, and then what? Write a treatise entitled, "The Engineering Trade-off as Analogy for the Human Dilemma."

(3) Interior design -- the large box has a partially-dedicated compartmentalization to separate one-time use gear such as flares, flare-gun, light-sticks, from hardware such as radio, light, tool kit. The concept is that you want to be able to plunge your hand inside and snap up exactly what you need for type I emergencies ("Help!") and type II emergencies/issues ("Oh, damn it all.").

(4) Now Decide How Many Boxes You Need -- "And why do you have two boxes?" Because....epics are fine, but every day on the water need not promise Green Giants, scylla, and other events worthy of entry to the Explorer's Club. For those days, and those boats, an option for a small box is good. I may be wrong, but I think all the flares, radio, tool kit, etc., are a bit of overkill for kayaking a few hours in the local river-swamp.

(Marginalia for the Positively Pedantic -- Note the saw, which I made from a replacement sabre-saw blade with handle wrapped in epoxy-soaked nylon cord. Why? I could find the size that suited me, and make it cheaply since tools are known to rust and be lost. Why carry a small saw? Because you never know.... Other tools are a Leatherman and a hand drill, and in fact have needed both for repairs, once. Sheaths for saw and drill made from polytarp and ductape, loose fitting and stiff to allow aeration.)

Step 1: Design an Ergonomical-Spatial-Temporal Context for Your Boxes

Design an Ergonomical-Spatial-Temporal Context for Your Boxes

....because boxes do not just exist in a Black Box! Boxes exist in a great continuum of connections. The most immediate one is the place it will be habitually placed; you may think of other contexts on your own.

(1) For now, let's focus on the comfort-to-size ratio -- Specific Example, the paradigm of which is to be extended to all boxes in existence -- The small box should nestle between your legs or behind your seat in a kayak -- that is the best I know how to set its comfort-to-size ratio. It should carry a lunch, small binoculars, camera, cell phone, wallet, small ditties (first aid, nylon cord,etc.), perhaps a small signalling device (flare gun will fit, electric strobe -- I keep a strobe on my lifejacket and that is enough for me for lazy boating), and perhaps a thermal undershirt or poncho.

(2) That done, now do Thought Experiments by asking, "How Might I Be Flexibly Adapting My Box?" ....

(a) Example: I added double handles at top that double as the "roll bar" that can hold and protect exposed items such as compass, GPS, binoculars, light, etc. The holes in the handles are for elastic cords to hold in your exposed items. I ennvisioned, therefore, how I would be using the box in a typical afternoon of kayaking -- what things I would careless place on it as the space between my legs is put to efficient use.

The larger box has a similar protective cage (compass is permanently mounted but room for GPS behind the bar). The second watertight screw-cover thing is a small compartment for small stuff you might want handy right away (keys, ID, money, medicine). I am uncertain as to its usefulness; the paradigm has weaknesses (aka "over-designing"). It is right where I tend to put my foot when sailing, or where I would sit if I put the box down on a wet beach to sit on.

(b) The blue elastic cord is to let you jam things under in case you are rushed and have no time to unscrew lid, or to hold stuff safely that need not go in the box (poncho, windbreaker, length of coiled rope). Many sudden needs arise in boating; for such times, I wish for you an enoughness of blue elastic cord.

(3) Next, ask, "What Could Happen to My Box?" (answer: lots, so: Then Armor High-Wear Areas) -- Both boxes sit on "skids" that you can't see here to keep their bottoms out of the constant wetness often found at the bottom of any boat and to take up most of the in-boat abrasions (yes, the boxes are waterproof but life is flawed and so isn't much waterproofing). The protective side rails and the epoxied on rope around the aft edge also protect the box from the knocks that it suffers in my crowded outrigger canoe -- the idea is to reduce the chance the the epoxy coating will be breached and let in moisture.

(4) Design to Keep the Boxes -- Both boxes have strong provisions for attaching to your boat (you barely see the SS eyehook on the small box, held in by interior nut with washer). (See photos on next page). I suggest attaching to your boat by a length of rope, because in a capzie you want the boxes to float free; you don't want to take a breath and get under the boat to find the emergency box. Yes, it might happen to stay there any way, but at least you did what you could.

(5) Think of the Inside Attachments -- Besdies tying screw-covers to cords leading inside the boxes, you might want subsystems in place for the contents. Example: The yellow bag on the safety cord is to hold daily objects such as cell phone, keys, wallet, and is clipped to a second safety cord. (That assumes you don't carry both boxes and save the large one for gear you hope you need not use, and the small box for gear you will probably use. There's a whole ritual possible here.)

Step 2: Box-Building Issues With Many, Many Steps

Box-building Issues

In response to reader discontent -- for after I am done being pissy about tones of voice, I do aim to please -- I may create a whole new instructable called, "how to build a rectangular box." For now, this advice:

(photos will follow: must build more stuff to take them)

PREFACE: if you read nothing else, please,please read step "i" which is my favorite.

(a) 3D rectangles are best because they maximize innerspace and don't roll around.

(b) So in the thick-wood-method for making boxes, use all those 3/4 inch pine scraps you have around, first deciding on the size of the 3D rectangle you need -- for me the width of the bottom of my narrow outrigger canoe set that parameter (tight enough to wedge a little aginst the hull sides); your parameters may differ -- and then cut out the pieces properly. I suggest a saw but an adz might do as well if you grew up with one.

(c) join the edges by overlapping them (photos will follow in another revision; I have to build a new box or a simulacrum to take photos). Don't do the 45 degree corner angle method (harder to clamp). Instead, spread one board edge with thickened epoxy or polysulfide, overlap the side of the other board, and clamp (then drill pilot holes and add bronze ring nails or SS screws if you used polysulfide). I favor epoxy to avoid using metal fasteners.

(d) For the marine-plywood option, cut the rectangles as stated above, then glue quarter-round stock to the edges of two sides to provide a wide gluing and support surface to attach the other two sides. Stop the quarter-rounds 3/4 inch short of the ends to leave room for two end-squares of 3/4 inch pine, which I find easier to use than plywood for the ends. The flange of the screw cover will screw on easier that way.

Yes you can just glue the ply edges without quarter-round supports (or the thick pine end-pieces), but 1/4 inch ply, or thinner, is a bit thin for that unless you are a watch-maker. The weight is not much extra in relation to the ease of gluing and strength you will gain. Also, ply is not always pefedtly flat, and you can't plane it flat like you can pine boards, so the pine end-caps and the support edges help you flatten the assembly at final clamping and gluing.

(e) Finish the basic box. Until I tell you how, perhaps you might find someone else's Instructable here about box-building. I haven't looked yet, but I would be proud to be the first. There are 37 methods, I know 3 of them in detail. One of those methods was taken to Death by the Devi Asua Aben Lapur in AD 512.

(f) Buy commercial "inspection ports" from a marine store. Various sizes exist, but use the screw-cover kind. Chose opaque covers if you want to stop the sun, choose clear covers if you want to look inside to see gear or check for leaks or let things inside the box see out (you never know).

(g) Scribe a circle in the plywood or pine bu tracing around the outide of the cover flange. Then drill a hole just inside the circle; this is to insert a jigsaw blade, insert blade, and attach the saw to the blade if you forgot, and cut circle out. Next, sand edges of hole and fair to fit the flange snug nut not so tight as to warp the flange (drum sander on drill press works well for theinside of circle cutouts).

(h) Now undo some of your sanding by roughening the cut out where the silicone goo will be glopped. ADVICE: do not use polysulfide here! Not good on the plastic flange). Insert flange, wipe excess goo with finger.

(i) wipe gooey finger on an expensive suit you intend to display to show your Un-stiff, Rebellious, Anti-Establishment Ideology.

(j) Use SS screws to attach flange to wood after drilling little pilot holes (let goo get in holes; see, I planned it all!), put in screws, let dry.

Whew! Do you like these new steps? I am exhausted from stepifying. However, see yet another step on interior design...

Step 3: The Inside Matters

The Inside Matters -- A view inside the large box.

What will hapen to the gear inside the box? It could roll around, rattle, drive you crazy on one of those slow choppy days at sea, and even explode from the shaking. The solution: foam and divider wall.

(1) Think, sketch, design the inside. You know best what you need. Another space here for your personal requirements:

(2) Make divider walls strong to function also as a girder to strengthen your box.

You will note the divider wall inside, which not only protects equipment from knocking around and permits organizing princples, but also adds strength so that you can sit or stand on the top of the box with impunity. Why would you? Well, you might, that's all.

More likely, a wind gust slapped your outrigger canoe, you put your foot down for balance, and you stepped on your boat box. That is really the idea behind the whole thing. The blue foam protects the VHF radio. Additional foam you can't see reduces the annoying knocking of the flares (and I have a silly and secret fear they could go off by accident inside if they bang around a lot: I know they can't, but let me be silly just this time).

Note: before installation, drill a hole in the divider wall, or even a few, as provision for safety cords. You'll need one cord for the cover, and perhaps others if you worry a lot.

(3) Add cords to secure the screw covers. I think you also saw in the photo the cords that prevent loss of the cover: it is attached to a swivel-based snap-hook (both boxes have one) so that the cord will not be tight curlycue mess after a while of opening and closing the screw-cover. How? These plastic covers have relics of their injection molding: a nub of plastic. Drill through it carefully -- don't penetrate the cover! -- and attach the hook through this clever hole. Attach cord to the hole you made in the interior dividing wall for such a purpose.

I always add a second cord or a loop tied in the cover-cord so that you can easily carabiner-on other gear you fear to loose in the act of getting at it.

Step 4: Award-Winning Exterior Details

Award-Winning Exterior Details

First -- Go back to Step 1, substep 2a, concerning the innovative roll cages I put on both boxes. In a word, they hold and protect delicate thing attached to or laid in those areas -- such as compass, GPS, binoculars -- and if they are inside the cage, are somewhat protected from the errant crushing foot that so often flails around an outrigger canoe in choppy seas.

Next, notice the protective lugs on either side of the hatch on the large box. Remember, you will be kicking these boxes around whether you want to or not. Or dropping them; or a wave will shudder them.

A note on the screw covers -- I like clear covers so that you can see inside (any leaks?). You could also turn on a nonwaterproof flashlight, batten it down under cover, and still see. These commercial "inspection ports" are pretty good but not fool proof. They can slowly leak if not tightened down hard. Yes, I did the submerge experiment to test that.

The bottom matters -- Look at the view of the bottom, which shows how I made sure the securing/carrying strap will not tear out when the inadvisable or forced surf-landing you thought you could handle tries to distribute your essenses in a fair and even way to the shore dwellers. The bottom bash-flanges also function as, indeed, bash flanges since the corners and edges of things in this hostile world suffer the greatest of insults.

A note about the epoxied-on ropes -- I meant well. I was protecting the plywood edges where the plies are exposed. I coated them well, but you do not want water getting in edges of plywood. I was experimenting with coated rope but later I decided on wooden bash-flanges and skids. I left the rope -- why waste it? For you I suggest considering the use of epoxy-soaked rope for a variety of engineering applications.

Step 5: Finishing Philosophies Wherein Everything Is Made to Fit, All Is Explained

Finishing Philosophy

(1) Do sloppy paint-job -- For me I suggest a sloppy paintjob; why make it beautiful when it is going to be kicked around and put on rocks and wet sand? I couldn't think of a reason why; any art I put into these boxes would be soon worn away. Plus, the boxes might seem more worthy of stealing. On the other hand, with art they would be easier for the police to find and return to you. Now I don't know what to tell you. That's because I'm honest. See next paragraph.

IMPORTANT PARAGRAPH -- Scholars who deconstruct the hidden agendas of "technical writing" will tell you even the plainest seeming technical documentation contains politics, perhaps even nasty hegemonic power politics full of lies, greed, and hypocrisy. I do not claim to have hunted down all of my own writing demons in this way (and I like some of them), but at least I can do what anthropologists call "thick description." This is a style of keeping records that preserves all data, ideas, doubts, etc., even if on the whole the record seems thick and messy -- because, the idea is, a smoothly edited piece of documentation more easily hides its agenda behind slickness.

(2) If you prefer, do a great paint job. How?

(a) Make no mistakes with the epoxy. As soon as it drips and dries, forget this step. Go back to step 1 and be happy. If you continue with step 2 any way, you have a class A personality (A does not always mean "excllent" by the way) and I can offer no advice. I am a beta-male, not an alpha-male. That means I want no followers, nor to I care where you go; no hard feelings if I don't follow. My bloodpressure is 110 over 70, not too bad for middle age.

(b) How to avoid mistakes with epoxy: paint a thin layer on, just enough to stick the fiberglas on, then lay fiberglas on. Press the glass down until it soaks; where the glass cloth is dry, paint a little more epoxy on. Let the cross-fiber pattern remain visible; if the glass looks transparent at this first step, you might have "floated" it off the surface of the wood.

(c) Let dry, cut off ragged glass edges just before final hardening; bring a lawn chair to your workshop and a coffee pot with you to sit and watch the process the whole night through the first time you do it. Why? Just when you though the epoxy didn't drip, you turn your back, and it drips.

(d) Good advice: keep surfaces horizontal during glassing/epoxying; everything sets up best that way. This makes the process very long and frustrating for some. If you agree, see my step 1. Listen to Uncle Wade! Do the whole thing, let it drip whereever, pretend to sand it later, but in reality, just paint over the drips and go sailing!

(e) Paint on second epoxy layer -- enough to "fill the weave" of the glass. Let dry.

(f) Lightly sand to scratch up the surface of the epoxy. I say, go light with 150 grit, but if you hear different from an expert, take her advice instead.

(g) Now I'm lost. Do you prime first then paint, or just go to the topcoat over the scratched up epoxy? I have equally bad experience with both methods. Epoxy as a a glue is divine simplicity itself; epoxy as a coating mystifies me. So far I live with two or three coats of topcoat. It's gonna get banged to crap in my boat, anyway. I will leave a space below so that readers can fill in this step better on their own screens; use water-soluble ink in case you change your mind; please send me a photograph of your edited screen for my files:

Appendix to this step:

MY FEAR -- In trying to respond to reader concerns, now this Instructuable is even longer, and someone else will be angry at me. But consider: I am teaching you about not only a material box you can build, but also about the construction and implications of technical documents. Now you have one theory to carry to all the Instructables you read, and all other documents too, such as the instructions for assembling your new sound system, which, sorry to say, has a hidden agenda; you just weren't looking for it. My writing also has some agenda. What? A few people think my agenda is to ruin their afternoon with words. I don't think so, but then, if it is a subconscious desire, how would I know that?



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    23 Discussions

    I think More photo's would really help, but I think I will give it a try, but for one that will fit in a Kayak. Vincent Orange, CA

    2 replies

    I think I would prefer one for a kayak myself. I have used the small one more than the large. The small one fits between my legs in the kayak and carries the little things useful there: camera, monocular, wallet, cellphone, small first aid kit, compass, light, and a length of line. The large one was built too heavy, I see now, for a small boat. Version three will have lower profile, and angled front to accomodate the screw-hatch while keeping the box only about 5 inches high total, about 7 inches wide and 15 inches long to lay low on the front cockpit seat of the outrigger canoe. This new one will have two compartments, one with an eight inch screw hatch on top for stuff carried for that trip: camera, phone, wallet, monocular/binocs, etc. The second hatch on the front will get at radio, flares, light, tool kit (stuff always carried in that box for coastal sialing). Since the Pelican marine flashlight is waterproof, that might even go in a protected niche outside the box.

    I have been making paddle floats out of a Nylon bag and a PFD, this came about after the blow up one I had would not hold air.... I have a an Idea on how to make one that will work as an out rigger.

    I use kitty litter buckets with a bungee cord holding the lid shut, I have gotten all I needed for free. I like that fact they are smaller, not big like a 5 gal bucket, and are usualy squareish so they don't roll around. They aren't pretty, but they get the job done, if I had a custom size object or area to fit I would follow your idea though. nice instructable!

    One small suggestion to improve the seal around your inspection ports. Set the port in the silicone and let it dry BEFORE cinching screws up. If you do it before it dries, you will just squish out the sealant. Do it after and you compress your seal and it will improve the quality and durability of your waterproof seal.

    1 reply

    not to down your instructable (very nice one btw)(also really cool design)... but anyone in a hurry that needs something simple and effective you just purchase an old army ammo box, but that's only if you don't have time to build this.... buying your way out wouldn't be the instructable way.... one of the most comprehensive instructables i have ever seen, nice

    1 reply

    Sure. Or a big Pelican Box made for such things (though they are a little over-priced).

    I support your writing style wade. If i'm too busy i just dont read the whole thing, instead of complaining. I especially like how you have attached the hatch covers. I've lost my hatch covers (while out in the wilderness) so i really mean it. perhaps you should start a company manufacturing hatch covers with swivels attached.

    nicely done, and allow me to express gratitude for adept use of verbage in this plethora of contrived acronimonious illeterates. few clarifications: -source on clear screw tops/commercial uses. other options such as pvc screw end caps. -foam on the interior? carpet backing? upholstry? efis? -did you butt glue the sides to the 1/4 round or use the round as interior reinforcement and route off the corners? have you thought about making one out of efis foam with several coats of resin for the durable finish? it'd be terribly bouyant. showerboard or centra(sp?) as strengthening/cladding may work well.

    2 replies

    The screw cover is a Beckson, which can be bought/ordered in different sizes in any boating store, physical or on-line. West Marine and Duckworks sell them online (Duckworks carries a brand I have not used). The foam comes from an old sleeping bag ground-pad, closed-cell foam, buy one in most camping stores, The 1/4 round formed a gluing surface and a butting surgace and to round out the interior corners, all at once; ample epoxy used inside (and out) to seal it. I have tried to think of ways to build lighter ones. A guy posting on Duckworks put a hatch on the bottom of an old plastic laundry soap bottle (neat idea!) though I wonder how good the seal is between hatch and bottle? My big box is very heavy -- you can stand on it, throw it at a boulder, etc., but a lighter one would be nice -- I would use all 1/4 plywood and just one layer of glass, and a lighter interior support. My main need is for watertightness and strength, since a small boat has limited space, making it more likely that you will step on stuff at some point.

    i suspect that 1" or 3/4" efis foam (exterior closed cel insulation foam) laminated to either 1/4" ply or hardboard (and resin/fiber) and on the interior with showerboard will give you the rigidity and durability you want with less weight. not padded inside, but then that isn't necessary for everything. -very- bouyant too. i've had remarkably distressing luck with using plastic pretzel jars (think 1 gal pickle jars, but clear plastic) as semi hard dry containers. gluing a larger do not eat packet to the underside of the lid helps to dry it out more. they don't last too long, but the recycling folks don't seem to mind that they're abused.

    I took a word out for you. As for the other issue, dictionaries work well; I have and use a few myself.


    11 years ago

    I work for a white water rafting company during the summer and we are always tinkering with what gear fits in what ammo can the best. This method for custom designing boxes to fit specific items is awesome! Nice instructable.


    11 years ago

    Um More pics and better steps. WAAAAY to much text.

    1 reply

    Yeah, really! I mean, having to read something! The horror! *rolls eyes* Snarkyness aside, Wade Tarzia has written a very good Instructable (TM). The instructions are understandable and he added a little theory to round out the whole bit. This is one of the best instructables I've come across on this site.


    11 years ago

    I'm not sure how the portholes attach to the box, however could these boxes maybe be constructed out of aluminum or maybe a fueltank out of a racecar or somthing(minikeg)? I assume that the screws do not have nuts on the backs? where do you get the screw-on liddy thingies?

    1 reply

    The screws go into the pine boards. The good thing about wood is that it floats and does not add to buoyancy problems. Screw on lids are commerical products available at most marine outlets; search for "inspection hatches/ports." These are about the smallest (~4 inch internal diameter), and they up to about eight inches diameter). Some pop out, some screw out. I advise the screw type.

    Do the boxes float? because it would be a pity to have your box of important things at the bottom of the river/lake/sea.

    1 reply

    Both would float of course with the covers screwed in. But if they they filled up while opening, that's another story. The small one would float, I think; it has enough foam in it to balance most of the heavy things that would go in, and it isn't meant for holding a lot of heavy things. Times would be dicey for the large box. It has no metal in it except for the screws on the flange, but the foam padding inside might not be enough to tip the scale past neutral as this box has a heavy radio and tool kit. If my thought about adding an external foam pad to make the boxes something to sit on comfortably, then there you go.