View topic - Making Custom DIY Dry Bags

CraigB asked about the specifics of making custom DIY canoe stem and other dry bags, and I thought other folks might be interested, so I took this to a separate thread.

I mostly use heat-sealable Packcloth from Seattle Fabrics. They sell a variety of heat sealable materials, I’ve used their Packcloth and Oxford cloth; no reason to use lighter fabric for dry bags.

https://www.seattlefabrics.com/Heat-Sea ... _c_80.html

We’ve made custom dry bags for sleeping pads, camp chairs, guitars, banjos and mandolins, tapered end bags, book bags, shoe bags and more. Once you get the technique down the custom dry bag world is your oyster, and you’ll find other custom shaped dry bags that you “need”.

To answer Craig’s questions the tapered canoe stem bags are actually \_/ shaped, with the opening fold over seal at the narrower end, which is still plenty wide on a canoe stem taper. I use a cheap household iron. Some of those bags are 10 years old, often strapped to the deck of a guide’s sea kayak and used on dozens of trips each year, still going strong.

For more than you ever wanted to read about the process of making DIY dry bags, including photos:

https://www.canoetripping.net/threads/m ... ags.83031/

Chuck Holst’s instructions are a good place to start:

http://www.paddlewise.com/topics/boatequip/drybag.pdf

Again, I highly recommend making a simply cylindrical sleeping pad or chair bag first, and learning to measure and make the templates for cutting out the heat sealable fabric from that experience. I use a big heavy camp chair, so prefer it packed low, ie in the bilge water. A sleeping pad, lighter but equally bulky, can be stored higher up. In our decked canoes I sometimes have it strapped to the stern deck.

Making a couple custom DIY dry bags would be a lot less expensive than buying a new canoe just ‘cause gear space got tight, and any bags you make, even stem tapers, can be used in a different canoe. And, again, I was astounded at how much otherwise wasted dry storage a canoe-sized tapered bag provided in the stems.

A few more custom bags, the first custom DIY dry bags we ever made in 2011, all still in routine use:

Little Plucky banjo bag

DSCF2080 by Mike McCrea, on Flickr

DSCF2079 by Mike McCrea, on Flickr

Martin Backpacker guitar bag

DSCF2108 by Mike McCrea, on Flickr

Camp chair and sleeping pad bags

DSCF2183 by Mike McCrea, on Flickr

DSCF2185 by Mike McCrea, on Flickr

All in all a great winter canoeing project, and for a change one that can be unmessily done in the living room if need be.

Great post!

The original question that brought up DIY dry bags was a space & packing issue. For packing efficiency having a custom tapered bag in the stems //_\\ is far more efficient than a round peg in a triangular hole / O \.

In a decked canoe, where space can be at a premium

P8111157 by Mike McCrea, on Flickr

In an open canoe with spray covers, where the gear load can’t protrude too far above the sheerline

P9081205 by Mike McCrea, on Flickr

Other smaller custom bags as well; I bring a real book, a trip journal & pen, reading glasses and flashlight reserved for bedtime reading. Those can go in some larger dry bag or pack, but sitting out around camp I want them kept together and rain protected, so book bag.

FWIW a template for a flat or cylindrical bag looks like this

P3310024 by Mike McCrea, on Flickr

The corner notches, long and short side iron-over flaps and centerline slice will make sense the first time you make any DIY dry bag. I don’t really need corner grommets on a book bag, but what the hell.

P3300015 by Mike McCrea, on Flickr

P3300018 by Mike McCrea, on Flickr

I could have made it smaller, but sometimes I bring a bigger, thicker book. Good place to keep maps or guides that don’t need to be in the map case for the day’s travel. Or a Kindle.

Over the past 10 years I’ve made a couple dozen of those custom DIY dry bags for various purposes. They make great gifts for paddling friends.

I think your link has answered a couple of my questions, 1) the flap at top accommodates full length of webbing rather than sewing tabs on each side and 2) the black shiny strip at the top is gorilla tape, which you did to prevent tearing at top but I think would also aid in rolling up the bag.

The basic construction method calls for a sheet to be folded over itself, then heat sealed from the fold point at bottom of bag, across bottom and up side of bag; seems to me, the heat seal at that fold in the bottom corner could potentially be the weak point of the method, any special tricks there?

About the top flap, the webbing runs full length inside the long flap foldover. I do not enjoy sewing and smear a bead of adhesive sealant like any GOOP or E-6000 on both sides of the webbing, then clamp it down flat under a board before ironing just the overlapped heat sealable fabric together. And usually running a few sloppy stitches across the fabric ends where the webbing sticks out past the fold over.

Using double ladder lock side release buckles I don’t need to sew one buckle side in place.

The duct tape does help stiffen the fold over edge, but the webbing alone does a decent job of that. The duct tape does help prevent the fabric from tearing at the inner corner where there is not an ironed foldover. I’ve had one bag tear there, while trying to hurriedly stuff in a large camp chair, fixed the tear with Tenacious tape, still going strong.



I do dog-ear iron a triangle at the bottom corners, mostly so I have room for grommets, but that un-ironed top inner corner is the only weak spot. Before we started making the first bags we did a test iron, using 1” wide strips of Oxford cloth, holding the iron down for different lengths of time. The heat sealed seam on those test pieces is only a 1” square.

DSCF2187 by Mike McCrea, on Flickr

Sticking index fingers in the loops it was possible to pull the 5 second and 10 second test pieces apart, the 15 second ironed down test piece was impossible to separate. I have had shop visitors repeatedly try to pull that same test piece apart, no dice.

I aim for 30 seconds of firm iron contact along the length of the heat seal seam; in that regard it helps to put a clock with a second hand on the ironing bench. 30 seconds everywhere, moving the iron along a few inches at a time on a seam, takes longer than you think.

After each seam has been ironed down I take the ironing fence away, let the fabric cool and stick my hands inside to check that the seam is sealed straight. If I find a little oopsie wobbly area I just mark it and re-iron it.

Definitely use a piece of cardboard under the fabric, and clamp an ironing fence board atop the fabric at the depth of the desired seam; a 1” wide seam is enough. And, as is apparent from the photos, a large work table is a necessity.

Last thing (maybe); using transparent plastic instead of paper for the template helped. I cut some plastic to the 58” fabric width. When making multiple bags I could lay out the measurements Tetris-style for the least amount of wasted fabric.

If you make a bag (or bags) please let us know how it went, and show your work.

So chuck Holst's paper seems clear in that he uses two separate pieces, brings them together by heat sealing bottom and both sides. From mikes bag pictures and labels on his patterns, I think Mike folds over one side and then seals only bottom and one side, is that right mike?

That is correct, Chuck’s instructions use two pieces of heat sealable fabric, front and back as it were. We opted to use a single piece of fabric with a centerline fold. Not really sure why we initially did that, maybe because it was one less seam to iron, and it saved a whopping two inches of fabric from the ironed over seam on one side.

Pluses and minuses; our saved templates are one piece, and with a one piece template it was easier to test fold the template to seamed size and make sure we had made things correctly and the right size. But Chuck’s way would be easier if making a tapered bag, the cuts, slices and married angles on which get trickier than a cylindrical bag.

We struggled a bit with Chuck’s instructions on the first bag we made. One change from Chuck’s instructions that helped a lot, especially with larger bags, was using an 8’ long piece of straight edged wood for the ironing fence instead of a ruler or writing tablet. The 8’ long fence is as long as our ironing table, so we didn’t need to move the fence clamps along as often.

About the cardboard under the fabric that serves as an ironing board “cushion”, it helps to have a big piece of cardboard, at least as long as the fabric you are ironing, so that you don’t have to continually move the cardboard along under the fabric. And smooth-ish cardboard; the stuff that has visible corrugation “waffle lines” on the surface doesn’t work as well as a smooth surface piece of cardboard.

It is worth buying a cheap iron just for making dry bags, the bottom will eventually pick up stick-em from some area where an edge of the sealable side was oopsie-exposed while ironing, and you don’t want that residue left on the household clothes iron. Even so I have cleaned bottom of the shop heat sealable iron a few times to remove that residue.

With custom fitted bags, like a cylindrical bag for a sleeping pad, it pays to make them a bit wider than needed for a tight fit; it is easier to get the pad in and out, and if your measurements are a wee bit off it will still work.

Craig, I get the feeling you are planning to make a DIY bag or two. If (when) you do please let us know how it went and what you think of the end result.

Yes, I think I will make some bags but by the time I get the material, etc. it will be spring. However, the details are now well captured in this thread. I figured you were folding and that's why I wondered about the heat sealing at the fold at the bottom corner of the bag, but sounds like you haven't had any problems with leaks there, so its probably a good shortcut.

Just a few weeks before they were required, I did get around to building some custom drybags. Because I was concerned about tearing of the bag at the opening while stuffing, I chose the two piece method per Holst rather than the one piece folding method per McCrea. I'm happy with the 1" glued edges at the opening of the bag, no tearing problems over two weeks of use. In order to avoid sewing buckles, both Mcrea and Holst appear to have used longer loops of webbing, capturing buckles, folding the webbing and gluing the webbing loop joint into the folded material of the bag mouth. I thought this might create a problem if the buckles were ever broken and required replacement so instead, I left open ends with sufficient length to accommodate either a sewn buckle or an adjustable buckle(which I used, cheaper than paying for sewing). I used a fabric cutting wheel which I think makes this work quite a bit easier. My order of operations included 1) cutting the pieces about 1/4" over sized to allow trimming , 2) overlaying the pieces along the best matched edge, 3) heat sealing that one edge, 4) final trim of this first edge with cutting wheel, 5) seal the lip on one side of the mouth, 6) seal the other side of mouth, folded webbing in place. It's a lot easier to seal these folded mouth ends before the bag is completely enclosed and with the one edge already sealed, by laying the workpiece flat, you know where the joints on the opposite edge need to be. Just got my best fit and finish this way, 7) sealed the bottom and trimmed, and finally 8) sealed the opposing edge and trimmed. With the cutter trimming, I didn't flame seal any edges and have no fraying after 14 days use. Total construction time was about 1 hour per bag; of course this doesn't count the thinking, material ordering, cleanup, blogging, etc. If you count my labour, these are expensive bags but, lacking a commercial option for the sizes I needed, they were the ticket and did the job! While using on my trip, the 1" sealed edge on one of the bags retracted to about 1/2" with stuffing. I assume I just didn't give this edge enough heat sealing with the iron and plan to go back and seal it again, I don't think their should be a problem with this, ie. adhesive should reactivate, we'll see.