Make Your Own Gear: Silnylon Mountain Poncho

A question for both Roger and Eddie:

When it's raining cats and dogs, what is the series of procedures to take your pack off while remaining dry? I am having trouble visualising it, and as this is something we do many times each day, it a really important consideration for me before undertaking this project.

Hi Lynn

> When it's raining cats and dogs, what is the series of procedures to take your pack off while remaining dry?

Ah well, this can be tricky if you forget. If I have the little safety straps tied to the load-adjuster straps on my pack (normal), I have to unclip them first. If I don't, the poncho stays with the pack. Normally I would get Sue to do the unclipping for me: it only takes a few seconds. Then I make sure the velcro strap under the pack is not done up, or at least is out of the way.

Once both of those things are done, I just carefully slip the shoulder straps off my shoulders and lower the pack to the ground. Very easy.

Mind you, with a light pack I don't always bother dropping my pack at every stop. Sometimes I just stand there; other times I sit down with the pack still on.

Having taken the pack out from under the poncho, it can now get wet. But my packs are made of waterproof X-Pac fabric so that isn't really a problem.

Cheers

Thanks Roger. So I gather that having the poncho go over your pack is for ventilation purposes rather than to protect your pack from rain? Which would appear to be diametrically opposed to the Packa design which appears to lean more towards protecting your pack first and foremost, while use as raingear would be secondary. I assume this because The Packa is intended to bungy onto your pack first thing in the morning and only be deployed as raingear if needed. I can't see a way to remove a pack while wearing The Packa without getting wet, and once in camp you would have to choose whether to protect your self or your pack (for the majority of us who don't have waterproof packs). Ahhh, in search of that ever-illusive perfect rainwear!

Hi Lynn

> Ahhh, in search of that ever-illusive perfect rainwear!
I think that does summarise it perfectly!

I don't HAVE to protect my pack or Sue's pack from rain, but I choose to do so for two reasons. The first is that seam-sealing on heavy fabric (my pack) is never perfect; the second is because the poly-cotton canvas used on Sue's pack can absorb water and get significantly heavier.

Yes, the Packa design seems to focus on attaching the Packa to the pack first and foremost. Removing the pack and retaining the Packa on yourself is difficult. I didn't want that problem.

The origin of my design was the frequent afternoon showers on the GR10 in the Pyrenees. Every time a shower started we would stop, take off our packs, get out our parkas, put them on, pick up the pack, etc. But when the shower stopped we had to repeat all that in reverse because otherwise we got too hot and sweaty. So fast deployment over me while still walking was basic. But almost as important was not losing my rainwear when taking my pack off.

I remember pitching camp one time just below a col (GR10) as the rain and wind got going – without a parka. (I was being tough and didn't realise how bad the weather was getting.) I was shaking and hypothermic by the time I got in the tent. And I remembered seeing all these French walkers with their ponchos having far less trouble. (They don't wear parkas in France when walking.) That was the background.

My pack is reasonably water-repellant anyhow. Sue carries a light small silnylon pack-cover as well for her pack on serious trips – it's really light as it only has to protect her pack briefly. Then her pack goes in the tent.

Cheers

Silnylon is not for me, sigh. I have tried it out, and I can't get used to the clammy feel of it against my skin (I often wear short sleeves under my raincoat), and the noise it makes when you are moving. So I think I will take the lazy option and add a cuben extension to my DriDucks jacket. The cuben will cover my pack and allow me to wear the jacket over the straps and hipbelt to improve ventilation, but will still stay nice and soft (and breathable) against me skin. It won't be very durable, but DriDucks are cheap enough (and easy enough to repair with duct tape) that I will just replace it as needed. It's a shame as I really like the durability of silnylon, plus Roger's design would improve airflow compared to my plan, but I won't know if it will work until I try it.

In the UK , the chain/webstore http://www.decathlon.co.uk/EN/hiking-ponchos section has an breathable poncho with arms: the Quechua FORCLAZ 1500 AIR CAPE. The hood could be improved, and might want full front opening…, but looks like a head start over complete MYOG.

Hi Alan

Why not? Whatever works.

Yeah, the hood does not look great! It could be enhanced maybe.
And yes, a front opening is definitely to be preferred imho.

Actually, you could use several of these ponchos as a starting point. Pity they don't mention the weights. And watch out for the PVC ones – they won't last very long!

Cheers

The Decathlon store mentioned actually seems to have a "Forclaz 900 cape Flower" poncho with front zip: so just the hood to fix

Roger —

This poncho looks great.
I have PDF drawings of the three pieces.
I will print on an e-size plotter for a pattern.

I have a question on the hood drawing. See the markup.

Will I be safe if I just scale your drawing? Thank you.

Hi Timothy

Scaling the drawing will be perfect. It is accurate.

Mind you, getting an exact copy is not all that important, just as long as it fits around your head and face and mates onto the opening in the main body. Making up a dummy with bits of an old sheet and small pins is always a smart move.

Cheers

Thank you.

I will heed your hood advice.

The hood looks like the hardest part.

(edit)
Progress has been slow, but steady.
Drew the pattern in CAD. Printed, pinned and cutout the pieces.
Used a knife and a large cutting board instead of scissors.
I have the sleeves attached and the hood finished (2nd try)

Whipper snipper cord is weed whacker cord. It worked really well.

Attaching the hood and storm seal this weekend.
Waiting for the kamsnap pliers and snaps to arrive next week.
Finally in the home stretch.

It would have been easier to split the front seam and then attach the hood.

Done. Just have to seam seal and hope for a rainy weekend.

Nice pattern Roger — thank you for posting it.

I found cutting the pattern was easier with a knife and cutting board.

Kamsnaps worked well.

Results

191 grams.

I just made (a month ago) this poncho. It works great and looks wonderful with a few problems.

1) Without putting the front closure all the way to the top the hood flaps over my eyes. Since I like the hood when its snowing/raining, but don't want to close the front all the way this is a bit of a problem, I wonder if I couldn't use thicker fabric for the hood to make it stiffer, or double up hte brim somehow.

2) the silny i have rips easily and is not very waterproof…. anyone know where to get that "wetlook" stuff the author talks about? I am thinking of going to 1.9 oz silny or trying some of the other things that OWF Inc have for offer, like 1.9 oz with a urethane coating. No longer so lightweight, but bushwacking in the Gila and SE Utah is not a place I want to destroy my nice poncho.

3) I used heavy duty thread, oops, probably added an extra ounce

4) How do you seam seal these seams? I am having trouble getting the under arm areas without doing them one at a time, maybe patience is all I need.

Lastly, I was using it over a g-5000 mystery ranch pack and it was al little tight. I added a 3 inch strip to one side of the side seam and it fits fine now.

Great work!

David

Dave,

No pictures? Don't be camera shy now.

Did you lay it out by hand on the fabric?

Tim

Hi Chocolate Frog

> the hood flaps over my eyes.
Easily solved. Put a little tab at the back of the hoof with hook&loop tape, That will let you pull the top of the hood back as needed. This is often done on commercial parkas, and looking at one in a shop would beat trying to explain, by a mile.

> anyone know where to get that "wetlook" stuff the author talks about?
Yes, current Westmark silnylon is very poor. But the wet look stuff is no longer available anywhere. Which is a PITY!!!! If anyone wants to sell me 10 yards of the wet look they have lying around … let me know!

> but bushwacking in the Gila and SE Utah is not a place I want to destroy my nice poncho.
Could be a good idea for those conditions. Horses for courses.

> How do you seam seal these seams? I am having trouble getting the under arm areas
A messy business. But I only bother seam sealing the top surfaces. I find sweat condensation to be more of a problem than a tiny leak under the arms.

Cheers

I have been following the thread about (RSBTR )SilPoly on a different thread and it causes me to consider this project. I made one of Roger’s ponchos from a piece of 1.0 cuben and a piece of 1.9 cuben that was left over from a different project. While it works well and it’s light enough for me, I do not like the plastic bag sound and feel. I am considering making another one from one of the new fabrics and wanted opinions from the experts. http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/98106/index.html MEMBRANE silpoly CG-PU2000 Thickness = .038mm Small sample areal density = 1.10 oz/yd2 New Hydrostatic Head = >3,514mm H2O Aged Hydrostatic Head (5,400 wet-flex cycles) = >3,514mm H2O Membrane Silpoly Thickness = .036mm Small sample areal density = .92 oz/yd2 New Hydrostatic Head = 633mm H2O Aged Hydrostatic Head (5,400 wet flex cycles) = 492.09mm H2O 1.1oz SP 2nd Gen Thickness = .049mm Small sample areal density = 1.21 oz/yd2 New Hydrostatic Head = >3,514mm H2O Aged Hydrostatic Head (5,400 wet flex cycles) = 492.09mm H2O Or the fabrics from this thread: “The Optimal non-Cuben Tent Fly Material “ (http://tinyurl.com/pglyu9j) 6. – "1.1 oz Silpoly 2d Gen PU4000- Olive Drab," that Ripstop by the Roll has been selling. They spec it as 1.4 oz/sq/yd including the coat, and 4000mm HH. I tested initial HH >3515 mm H2O, aged HH >3514mm H2O, thickness .047mm, and areal density 1.40oz/yd2. The comment linked here makes me pause and wonder how to evaluate the strength to weight along with durability of these fabrics. “A new Silnylon available – 1.05oz/yd” http://tinyurl.com/psbuo9q “A. Membrane SilPoly (PU2000, 1.03 oz/yd^2, 15D plain-weave) B. 1.1oz SilPoly (PU4000, 1.4 oz/yd^2, 20Dx20D) C. 1.1oz SilPoly (1.24 oz/yd^2, 20Dx50D) First, I poked a small hole in each fabric using my seam ripper. I was unable to get the hole to propagate or the fabric to tear in all 3 fabrics. It seems pinholes do not matter here Next, I cut a small slit in each fabric, about 1/2'' long, using a pair of scissors. Fabric A tore without much effort. Fabric B was better than Fabric A, but still tore. And Fabric C did not tear at all, but you could see some deformation of the fabric. This is surprising to me since Fabric B seems to be the most substantial and puncture-resistant of all 3 fabrics. Keep in mind this is all subjective though.” My questions arise based upon my plan to step off on the AT Spring of 2016. I grew up in Western North Carolina and suspect there will be plenty of opportunities to snag and tear a poncho. I used some of the PU-4000 as a floor on a tent I am building now & it’s an interesting material. What do you experts suggest?

Hi John

I was away in the mountains when ypu posted your question, then the BPL web site moved, with ensuing confusion.

What do you experts suggest?

I am not going to try to second guess between three fabrics without samples. However, what I would do is experiment! Make up a poncho from one of the materials and try it out! In practice, I find that silnylons tend to slide over scrub in the wet and not tear, so maybe going for the best HH might be an idea.

HOWEVER, remember that the PU coating may degrade during storage. It goes sticky. For this reason I usually remain with straight Si/Si.

Cheers

It seem the top decathlon cape may need not modifications at all:

it already has side pit zips and a better hood and full front zip: https://www.decathlon.co.uk/forclaz-75l-l-xl-rain-cape-rd-id_8302454.html

That Decathlon cape has a lot of interesting features, including a low price tag of $49.99 in the US:

https://www.decathlon.com/products/trekking-raincoat-forclaz-75-liters

However, it weighs 508 g / 17.9 oz (S/M) to 560 g / 19.8 oz (L/XL)!

The 284 g / 10 oz SMD Gatewood Cape is about half that weight – and almost 3x the price at $135.

https://www.sixmoondesigns.com/collections/tarps/products/gatewood-cape

— Rex

ThePacka in silnylon: Medium, 9.5 ox, US$122
Personally, if I had to buy a poncho, that is what I would buy.

Cheers