DCF Pyramid (myog)
Mar 17, 2021 at 5:08 pm #3705089
I do not claim any of my process to be the correct or best methods but they have proved to work well enough for myself.
I’ve been asked by a number of people for more info so I figured I would start a new thread. I’m not going to go into every detail but I certainly welcome any questions as to the process or results or w/e.
Last year I took on the challenge of my first cuben fiber project. The material was new to me but the design was not. I have been using pyramid tarps for years from a MLD cricket to their duomid to my own MYOG silpoly pyramid. Through the years, I have been able to narrow down the perfect dimensions for myself.
I spend most of my time doing research, as best to my abilities. I spent countless hours reading through the bpl forums, hammock forums, youtube videos (suluk46, ty), google searches, etc. and decided I wanted to go with a mostly bonded approach as compared to sewing and taping or other variations on dcf work methods for a number of reasons.
The pattern is always the most difficult and frustrating part for myself because I do not have sufficient work space for the size of the project. I used googles sketchup to design my pattern based on the chosen dimensions. Learning curve here as I never used this program or anything like it before (I’ve played around with photoshop in high school)…I translated the computer pattern to the dcf fabric by hand using yard sticks, rulers, and a new tool to me; 5ft long t square. This was very nerve racking as it’s the first time I’ve worked with such expensive material. I measured 4+ times before marking the lines and then rechecked all measurements again afterwards. I calculated the catenary cut ridgelines and marked the entire curve by hand at each 1 inch mark rather than making a template first.
Two patterns were needed for the total of four panels. They were cut out and then lined up to ensure accurate cutting/measuring. Each ridgeline was then bonded together using 3m transfer tape. Reinforcement patches were used at each of the four corners, mid length of the bottom hem, mid panel guyout locations, along with mid ridgeline guyout points.
I sewed the bottom hem to save weight over more bonding and to “lock in” the bonded reinforcement patches on the bottom and corners. The mid panel guyout points are sewed together and then bonded onto the main fabric panel. The ridgelines guyout points are bonded patches with the attachment point sewn through the patch, two layers of main panel fabric, and bonding adhesive. This is then further reinforced on the inside to also maintain the waterproof seam.
The waterproof zipper was sewn onto a strip of dcf fabric and then bonded onto the main panels. Another strip was bonded overlapping the other strip to waterproof and provide further strength to zipper fabric connection.
The peak cone was first reinforced by bonding 1oz dcf to the to panels before construction of the bonded ridgelines. Further inside reinforcement came by using strips of 1 inch and maybe 1/2 inch 2.92oz dcf tape bonded inside. I intended to use the trekking pole handles rather than the tips. This saves weight over a full coverage inside cone.
The peak vent was just a mock up of several shapes in a different scrap material until I got the correct proportions. The inside was simply sliced out and reinforced.
100″l x 60″w x 50.4″h
.74oz dcf main fabric
1oz and 2.92oz reinforcement fabric
Total weight including 1.2mm guyline, 4 dac vstakes, 8 titanium skewers, and silpoly stuff sack is right at 16oz.
I used this tarp to hike the entire Continental Divide Trail and it performed flawlessly. Here are a few pictures of the end result:Mar 17, 2021 at 5:10 pm #3705090Mar 17, 2021 at 5:13 pm #3705092Mar 17, 2021 at 5:17 pm #3705096Diane “Piper” SoiniBPL Member
@sbhikesLocale: Santa Barbara
It looks professional. I’m jealous of your CDT trip and all the great places you camped.Mar 17, 2021 at 5:21 pm #3705097Monte MastersonBPL Member
@septimiusLocale: Changes Often
Dude, you knocked it out of the park with this one. Very impressive.Mar 17, 2021 at 5:29 pm #3705099Jerry AdamsBPL Member
@retiredjerryLocale: Oregon and Washington
nicely done, thanks for the writeup
you measured 4 times, then checked again? That would be “measure 5 times and cut once”. I see no wrinkles in your setup so that worked
How did you attach the panels together? DCF tape?Mar 17, 2021 at 5:53 pm #3705112dirtbagBPL Member
That is great!!! What length trekking pole?
If you plan on making/selling one from silpoly or silnylon.. hit me up, lol. Nice work!!!Mar 17, 2021 at 6:16 pm #3705118
It looks great. would be interested in seeing closeups of how you reinforced the peak! The peak is the worst part for me.Mar 18, 2021 at 7:58 am #3705170Chad SBPL Member
I can never wrap my mind around how a catenary ridge is achieved by overlapping 2 pieces of fabric, especially non stretching fabric like DCF, like you have on each of the 4 edges. Can you (or anyone) provide pictures or a video of how this is achieved? Maybe a picture of what the patterns look like before bonding would help me.Mar 18, 2021 at 1:39 pm #3705220matthew kModerator
Drawn on my phone with my finger in the way but I imagine two panels come together like this to make the cat curve.Mar 18, 2021 at 1:47 pm #3705224Chad SBPL Member
What would the next step be? How do you overlap those 2 edges to bond them together?Mar 18, 2021 at 2:45 pm #3705235Erik GBPL Member
@fox212Locale: Central Coast
Wow, that looks excellent! Really superb craftsmanship.
I’d love a few more details on the peak as well – the vent and reinforcement particularly. Is there a strip of reinforcing material going vertically across the middle of the vent?
Also, what variation of 3M transfer tape did you use?Mar 18, 2021 at 3:08 pm #3705245matthew kModerator
“What would the next step be? How do you overlap those 2 edges to bond them together?”
That’s as far as I got. I’ll be interested to hear an answer too.Mar 18, 2021 at 3:52 pm #3705256
the cat curves are not aligned flat, it is relatively easy to mate them together if you have the tape already on the fabric, just line the tapes up and press, being careful as you go along. I imagine Dyneema does not need much of a cat cut.Mar 18, 2021 at 5:35 pm #3705277
Thanks everyone for the compliments!
Real quick here for the cat cut. The seams were bonded together using a single strip of 1″ 3m 9482pc tape. No sewing on the ridgelines. Done in small increments such as a couple inches at a time, the reverse curves bond together near perfect enough. If the dcf had even just a smidgen more of stretch then it could be easily done perfectly. Keep in mind that this entire cat cut is just 1.25″ over the entire length of ~77.”
I am currently making a replica using .5 dcf rather than .74. Utilizing a few different techniques, notably the peak reinforcement. I’ve been taking far more detailed pictures this time. I’ll post the full write up another time.
Hope this clears some questions:Mar 19, 2021 at 6:20 am #3705332jimmyjamBPL Member
@jimmyjamLocale: Mid Atlantic
Very nice! Where did you buy your DCF?Mar 19, 2021 at 10:17 am #3705368
Just curious about how much yardage you bought, and how much scrap?Mar 19, 2021 at 1:47 pm #3705384
I’ve bought dcf from both Ripstopbytheroll.com as well as dutchwaregear.com. Every once in a while you can utilize 10-20% off making it more reasonable.
I do not remember exactly right now but I believe I ordered 7 yards the first time and had plenty left over. Maybe close to a yard. This time I got 8 yards and I can let you know how much I have left within the next few days the next time I can get to working on it.Mar 19, 2021 at 11:16 pm #3705479Brian RBPL Member
Looks great Eric…I wish I had seen it in person when we met on the CDT, but that pavillion in the trailer park was hard to pass up :)Mar 20, 2021 at 6:40 pm #3705589
heres an example of how I am doing my current pyramid build.. i hope it helps visualive the final peak steps.Mar 20, 2021 at 6:43 pm #3705590
Here is a very helpful tip: when working with dcf and bonding with tape, feel free to use sharpie markers to create your pattern/cutting lines. When you prep the fabric for adhesive, both the rubbing alcohol and primer manage to erase all visible ink. Red, black, and silver.Mar 20, 2021 at 8:08 pm #3705598Diane “Piper” SoiniBPL Member
@sbhikesLocale: Santa Barbara
Those images with the tape make me feel nervous.Mar 25, 2021 at 4:37 pm #3706271
Michael, I have used the last of the .5dcf for my current build. I ordered 8 yards and have 58″ remaining. 58″x54″ Piece remaining after completing a 100x60x50.4 pyramid. I have to say I think i was very lucky in being able to use the awkward left over pieces for any extra reinforcement, panels, vent, etc. I did not plan this out though.
Eric. G, Yes, there is a strip of material going up from the bottom to top of vent opening. This is how MLD does it. My current build has the same strip (from zipper to top peak) but it is still from the main fabric panel and then reinforced.
I am using 9462 rather than 9482 on my current build. I was going to use 9462 on my first build but decided last minute to go with 9482 as it seemed that is what most people had used with little failure (not counting the cold weather dry bags). I’m using 9462 based on the simple testing that a member from another forum found that 9462 with primer and alcohol prep bested 9482 without prep/was plenty strong enough for the application. 9482 worked perfect for my first build and would not hesitate to use the same product again.
A couple more pics of current build:Mar 25, 2021 at 4:40 pm #3706272Mar 25, 2021 at 6:25 pm #3706286
Great craftsmanship. So the peak reinforcement material is just grey/black 1oz DCF? When I saw it at first, it looked kinda like DP liteskin.
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