...or does it have merit?

I plan to modify a cheap-o waterproof breathable jacket by adding a closed-cell foam “grid” to the inside. The foam would add some warmth, be impervious to moisture and create an air gap for a nice micro-climate while still remaining breathable ... that’s the theory anyways. It would be for winter use.

I got the inspiration from a combination of British gear maker Keela and Polatec’s power-dry used in garments like Patagonia’s R1 line. Keela garments use a sort of double-wall system which they claim keeps the user dryer and warmer in real world conditions compared other waterproof/breathable garments on the market.

I usually take a wind-shirt on all my trips and combined with the grid-foam jacket can sort of recreate the benefits of Keela’s jackets.

What do you think? Please tear this idea to shreds :)

Thanks.

What thickness of foam are you going to use? Will the grid be removable so you can wash the jacket at some point?

I think issues will be movement, feel, and weight/packability. Would need super thin foam (1/8" evo?) and perhaps plentiful mesh "seams" between panels to ensure mobility. Some tailoring involved. What I do like about it is it could double as a kind of padded groundsheet. But is it really that much different than the old REI Gortex jackets that just had heavier nylon mesh lining? I dunno. Only one way to find out!

Roy,

I've been using a float coat as my primary coat for several years now. A float coat is made of closed cell foam sandwiched between two layers of fabric. Is this what you are considering?

I'm a heavy sweater and the foam coat works well for me because the insulating value of the foam is unaffected by moisture. The coat is also my raincoat and part of my sleeping pad system. It is not a breathable fabric, however. I'm typically wet inside when moving and a little damp between my shoulder blades when I've slept in it.

For experimenting you might want to try this adhesive backed foam:

foam

The adhesive allows you to temporarily stick foam on a piece of fabric so you can then fasten it more permanently with tape, sewing, glue, etc. The stuff I bought is closed cell foam and about 1/8" thick. I haven't gotten around to experimenting with it but it looks like it has a lot of potential.

Daryl

Edited by lyrad1 on 10/19/2011 09:16:57 MDT.

Dan, being that this is an experiment, I’m gonna use cheap materials. I have a blue foamie - I think thickness is 1/2 inch or so. I hadn’t thought about cleaning. Perhaps if it works okay a solution will be needed, but I wanna test it out first.

Ozzy, the jacket, a Sierra Designs Hurricane LT from ages ago, is slightly over-sized so I hoping this will help with mobility issues you mention. Your right, one way to find out!

Daryl, I remember seeing some of you posts on foam vest, etc. Cool stuff. This idea is slightly different. Imagine an R1 grid fleece but made from foam squares attached to a wp/b face. When worn over a wind-shirt the effect would be that of a double wall tent with a solid inner fabric. Moisture could pass through the wind-shirt and condense on the wp/b outer fabric. The DWR on the wind-shirt would prevent the any moisture from being reabsorbed into base layer etc. The purpose of the foam grid would be to keep a gap between the inner wind-shirt and outer wp/b. Thanks for the link! Could be useful.

Thanks for the comments!

I've thought along similar lines, except

if you had super open cell foam it would be very breathable

Like, there's this cleaning pad, I forget the name, only problem is it has some scrubbing substance on one side, and they're too small

I wonder if you could find a sheet of similar stuff

And there are a few places that get more sweaty - like shoulders and head - for most of the rest of your body the fabric lays loosely so doesn't need anything

Wouldn't this in theory be the same as a ski resort jacket? The jackets are puffy waterproof breathable with down or synthetic insulation - imagine there's been some fleece lined ski jackets as well.

ADD: Maybe something like the Patagonia 3-in-1 Snowshot jacket? ..

http://www.rei.com/product/818799/patagonia-3-in-1-snowshot-jacket-mens

Not a plug for Patagonia, just seems a lightweight W/B shell combined with a removable puffy or foamy lining would reduce the gear closet..

Edited by hknewman on 10/19/2011 18:03:57 MDT.

jerry, well good to know that you’ve had a similar idea. The use of closed cell as opposed to open would be so that no moisture would be retained. hopefully the spacing of the foam grid would allow for good breathability. maybe open cell is the way to go. good suggestion on “mapping” for different areas of the body.

hk, nah this wouldn’t be like a 3-in-1 type jacket as the purpose of the foam is to create an “air gap” and not an insulated liner. check out keela’s website for a description of how their system works: http://www.keela.co.uk/index.php?main_page=page&id=14. That's what i'm trying to achieve with this project.

OK, now I get it.

This just has too many variables for me to come up with any opinions via thought experiments.

Looking forward to your hands-on-in-the-field reports and experiments.

"use of closed cell as opposed to open would be so that no moisture would be retained."

If the shell is waterproof breathable, you want to get any water vapor out to the shell

Closed cell foam would impede water vapor

> If the shell is waterproof breathable, you want to get any water vapor out to the shell. Closed cell foam would impede water vapor

That was my first thought, but then I read the OP a bit closer:

> adding a closed-cell foam “grid”

So I think the idea is to create a 'waffle-style' insulating lining to the jacket. I'd say that provided the foam isn't bonded to the shell (i.e. air can still circulate between foam and shell), then the reduction in breathability may not be too bad.

My suggestion for cheap insulation to experiment with, would be, as it often is, EPE foam ('JiffyFoam'). We just received large package at work with a load of 9mm anit-static EPE sheets (woohoo! already secreted away...).

Or, use 3D spacer mesh from other thread

I googled it, one link I saw is http://wellcool.en.alibaba.com/product/288812985-50071028/3D_airflow_fabric_10mm_SF0910_C_.html - minimum order 1 meter but no price given.