I was just being a smart arse. Plan on making a gun case. Thanks for the idea.
Muskrat, I like smart asses, but even so apologies are in order. I found a copy of the 2011 project report originally posted to Solo Tripping and read it. It does
sound complicated.
OK, both Joel and I were admittedly dang confused reading some of the “instructions”. Comically confused, mystified and asking each other “WTF does that mean?” at times, but once we got started on the first bag everything became clear.
I had forgotten some of the tricks and tips we learned, so it was good to re-read that DIY project post. Especially since this discussion prodded me to buy another couple yards of heat sealable material.
The two-day DIY project “trip” report is appended below. There were originally several dozen (Webshots) step-by-step process photographs and descriptions embedded. I took all of the defunct links and photo references out.
It is now a lot of photo-less verbose blather (I drank beer and typed while Joel ironed), but it was two days of learning while we got better at it, and may be worthwhile for someone planning to make DIY heat sealable dry bags.
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DIY dry bag project, Day 1
I ordered heat sealable Oxford and Packcloth from Seattle fabrics. And then read every on-line article on DIY dry bags I could find.
The best of the on-line guides I found was this one by Chuck Holst:
http://www.paddlewise.com/topics/boatequip/drybag.pdf
(There are also a couple of articles in old issues of Sea Kayaker as well if you can find them - (Spring 1990 and June 2002)
Neither Joel nor I are especially good at following instructions, and the formulas on page 4 of those instructions gave me a headache. We spent a half hour reading various instructions before deciding to wing it best we could and learn from our mistakes.
Tools and materials:
Large flat work surface. In this case a 4x8 sheet of reinforced (and gaudily painted) plywood on sawhorses.
Heat sealable dry bag material from Seattle Fabrics. We tried both the 220 Denier Oxford cloth and the heavier 430 Denier Packcloth. Each was equally easy to work with.
Large framing square (it helps to trim the material edges square before starting, so the heat sealed edges meet straight and true)
Scrap material from trimming the edge straight. We cut an inch off the end of the fabric – more than we needed, but we wanted the scrap piece to experiment with ironing temperature and time before we started on the first bag.
Cloth tape measure (it was easier to measure around the circumference of things like sleeping pads than to perform the math equations on page 4 of the instructions)
A thick wooden yardstick. Any piece of straight lumber with a right angle edge would do. We clamped this in place 1” away from the edges of the fabric to be ironed as a guide fence, so that the heat sealed edges were straight and uniform.
Clamps for above.
Scissors. We tried using a razor blade to cut the fabric, but scissors worked better.
An iron. The cheapest one I could find was all of $6. Having been in the doghouse for using the wife’s iron to seal Melco tape on a neoprene project it was time to buy one just for shop use.
Fastex buckles, the ones with double ladder locks for no sewing.
A piece of thick cardboard. An ironing board is
too soft and the wood table top
too hard. We put the cardboard under the fabric before ironing and it was
just right.
Paper clips. Once the edges were laid even we used the paper clips to hold them in place before installing the fence and ironing.
A magazine. It helps to press something down atop the heat sealed edges immediately behind the iron.
Practice makes almost perfect - The first attempt
Joel and I had previously read the various instructions several times. We read them again in the shop. We looked at the formulas and equations and decided that bit was beyond our weak math skills. I could have asked the physics major in the next room, but we were confused enough already.
We read the more puzzling parts aloud to each other and were still confused – “The top flap of the shorter piece stiffens the mouth of the bag to help it stay open”.
Huh? What? What shorter piece? We’re only going to have one piece of fabric, cut to size and shape and folded over heat sealable shiny side to heat sealable shiny side. Ah, screw it; let’s just cut the first piece and learn from our mistakes as we go.
We elected to make the first attempt using the longest and thickest Therma-rest, figuring that if we eff’ed up our non-formulaic measurements it could always be used for one of the shorter, thinner sleeping pads.
Measuring around the most bulbous valve-end of that pad gave us a 26” circumference. Add an inch for wiggle room, so it isn’t a struggle to get the pad into the dry bag. Add an inch on each side for lapping the heat sealable material. 26 + 1 + 1+ 1 = 29.
The big Therma-rest is 31” long when rolled, and the Oxford cloth is 58” wide. We know we need an inch at the closed bottom end to iron together, and some unknown inches at the top to fasten the webbing and buckles and to roll down at least 3 times.
No sense in cutting some wee scrap of cloth from the 58” width just yet, we’ll cut it full length, seal the bottom and sides and trim the top as needed.
Ironing the material was easy. The thick yardstick fence helped immeasurable. As did my handing Joel the iron and saying “OK, it’s ready”.
Sweet, we have a long waterproof envelope sealed along the bottom and sides. But we are still confused about how to install the webbing and fastex buckles.
A mistake. We read and re-read the instructions, and discerned that we should have cut the folded-in-half fabric so that there was additional length material on one half of the top/open end, like an envelope flap in rectangle.
We puzzled this out and determined that we need about 5” of flap fabric on one side at the top. We cut down a 5” wide section from one side of the bag for opposing envelope flap. Fortunately we had left a lot of extra material for the length of bag needed and had room to spare.
That 5” wide flap section is what encases the webbing on one side of the bag. The webbing is cut to length and placed under the fold, and the heat-sealable fabric beyond the webbing edge is ironed together. That provides a fabric sleeve for the webbing, and helps hold it in place for later sewing if needed.
Having successfully figured out the simplest form of DIY dry bag for a Therma-rest we decided to try making another tall cylinder, this one for a camp chair. Pretty work. It’s getting faster and easier with practice, and we have another custom fit
Feeling more confident in our dry baggery skills we tackled something trickier – a dry bag for Joel’s Banjo. This one would be a tapered bag, and required considerable contemplation. That contemplation eventually produced a paper template for the oddly angled piece, and the template allowed us to check the symmetry of the piece by folding it in half to assure that the heat sealable edges aligned properly.
That shape, once ascertained, required an epic amount of /_\ material for a tiny instrument, and I was pleased that we had first made the template and not misscut the fabric trying to eyeball the shape.
By golly I think we’ve got the hang of this. We’ve got a couple more to make; one for Joel’s guitar and a couple more Therma-rest bags.
If we can do this well on our first attempts anyone can make a custom dry bag.
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DIY Dry Bags, Day 2
Day 2 of our DIY dry bag making saw our routine better practiced, and comprehending the intricacies of instruction with additional clarity. I did slow the speed of our construction process down by trying to photograph every step along the way (hey, it beats ironing), so what follows is overly long if hopefully helpfully descriptive.
Step one: Square up the edges of the material. The sloppy cut on the side of the material came as-isfrom Seattle Fabrics. I can’t complain since they cut the yard lengths 40+ inches long.
We learned that is easier to make a full sized template of the needed material, including (and especially) the oddly shaped top cuts, and test fit that before tracing on the material and cutting. Duh.
This part of Chuck Holst’s instructions “The top flap of the shorter piece stiffens the mouth of the bag to help it stay open” suddenly made sense, especially if you substitute “shorter side” for “shorter piece)
For a Therma-Rest you need a piece of material 3” wider than the diameter of the rolled pad’s widest, valve end (3” equaling 1” on either side to overlap and iron together, and 1” of play to facilitate getting the sleeping pad inside).
Lengthwise you need 1” to iron over at the bottom, plus a minimum of 9 or 10 inches of extra material at the top to make the long and short side flap cuts outs. (Makes much more sense once you fold over and iron the first piece)
Once the rollover topside’s convoluted cuts, notches and webbing sleeve were completed all that remained was to iron seal the bottom, the side and the top (always in that order worked best)
That one was so easy we made two for identical Therma-rests. Practice quickly makes perfect. Two more done to near perfection.
Time to tackle something trickier – a bag for Joel’s Martin backpacker guitar.
That guitar has a very rugged case. That case isn’t waterproof and isn’t shaped at all like the instrument. And that case weighs almost as much as the guitar itself; it’s a backpacker guitar encased in a backpacker’s overweight nightmare.
Joel measured the size and shape and was confident in his dimensions. I was less so; we only have enough material left to cut this piece once, otherwise it becomes an odd sized tapered bag that doesn’t quite fit a tiny guitar.
Another template to the precautionary rescue. We cut a paper template to Joel’s calculated dimensions and, oh crap another template miscalculation, it’s a couple of inches too narrow at the mouth. Using that incorrect paper template we are able to discern the taper angle error. A new template cut and presto, a custom fitted, lightweight, waterproof guitar case
Template gooood. Winging it baaaad.
We put a grommet through the material on the bottom (even the 200 Denier Oxford cloth was tough to punch a grommet hole through) for an additional tie down point. Ironing over triangular a dog-ear flap of material provides plenty of sealed space for a grommet.
We finished up the day by making a few test strips of ironed over material, 200 Denier Oxford cloth and 430 denier Packcloth . Even at 30 seconds of iron pressing time that stuff was impossible to pull apart
Biggest lesson learned on day 2 – always make a template. We’ve got templates now for the Therma-Rest and Backpacker guitar (and we should have made a template for the little Plucky Banjo dammit).
The adventure continues as soon as we place another order with Seattle Fabrics. Should be a lot easier now that I have cut-out templates for a half dozen shapes and sizes.
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It was; I did another production run of custom bags all by my lonesome. Which is truly an invitation to screw up. And I didn’t.
