Poop Philosophy and Tyvek

TLDR: has anyone tried tyvek mailers for poop storage?

Long version:

From what I have seen there are basically two poop storage methods used—

1.) anerobic (soda bottle taped shut, protein jar)
2.) aerobic (Zabrok paper bags in mesh bag method)

The main contrast between these methods is  that anaerobic systems try to contain the stench (although you will likely get periodic “burps” of gnarly shit smell as pressure releases, and the polyethelene bags used in most wag bags aren’t particularly smell resistant), while aerobic systems try to reduce the stench through venting and drying.

In my mind, you’re surrounded by shit all the time that you usually don’t smell because 1.) it dries out and becomes less stinky, and 2.) the remaining stench is low enough to blend into the background noise of smells. With this in mind, it seems like the goal should be to moderate the stench released while at the same time drying things out. This leans toward the Zabrok method, but I’ve heard some say that the paper bags are still pretty offensive, and that rain can reactivate the poop. This makes me think about semipermeable materials, and specifically tyvek.

Tyvek is:

1.) light
2.) cheap
3.) waterproof
4.) breathable

This seems like a an ideal material, and you can buy a pack of 50 black (to aid drying) 9x12 tyvek mailers for $21 on Amazon.

My assumed method would be this:

Poop in a paper bag, place bag in tyvek mailer, hang bag in mesh for the climb. On the way down, transfer everything into a five gallon mylar zip bag or two (mylar is an effective smell barrier).

The devil, of course is in the details. Has anyone tried something like this, or will I have to science this shit to find out?

🤙

This sounds excellent and I nominate you to give it a rip for the next two weeks for science. 

Matt Carrollwrote:

This sounds excellent and I nominate you to give it a rip for the next two weeks for science

Do you mind if I leave something in your yard for the next week? Totally unrelated to this, clearly.

Who you gonna ship them too?   

Cherokee Nuneswrote:

Who you gonna ship them too?   

Surface shitters!

Cherokee Nuneswrote:

Who you gonna ship them too?   

The lowest bidder. Get your bid in now!

I’ll add that AI estimated this approach would reduce the “stink radius” by 70-80% while retaining most of the desiccation benefits of paper. That said, ai is often wrong, so I’m curious if this ‘loaf’ is just half baked or if someone has played with this shit already.

Just my 0.02, while Tyvek is branded as vapor permeable it is a vapor barrier.  It is also definitely an air barrier, though it is air permeable. Similar to how Goretex is “guaranteed to keep you dry”, which everyone knows really means it’s guaranteed to keep you wet. Tyvek is guaranteed to slow down any evaporation considerably more than paper.  

Put some stamps on the loaded Tyvek mailer, seal the envelope, and chuck it off the cliff.  Air mail...

Kevin Strickerwrote:

Just my 0.02, while Tyvek is branded as vapor permeable it is a vapor barrier.  It is also definitely an air barrier, though it is air permeable. Similar to how Goretex is “guaranteed to keep you dry”, which everyone knows really means it’s guaranteed to keep you wet. Tyvek is guaranteed to slow down any evaporation considerably more than paper.  

Tyvek and silica packets?

Kevin Strickerwrote:

Just my 0.02, while Tyvek is branded as vapor permeable it is a vapor barrier.  It is also definitely an air barrier, though it is air permeable. Similar to how Goretex is “guaranteed to keep you dry”, which everyone knows really means it’s guaranteed to keep you wet. Tyvek is guaranteed to slow down any evaporation considerably more than paper.  

That’s mostly what I am counting on.  Basically, the hope is that the tyvek will moderate vapor transfer rate and not directly expose liquid components to air, therefore keeping the stink down by reducing the amount of it released at any one time AND keeping things aerobic AND letting things dry out.

I am hoping that the tyvek will let enough water out to dry things, enough air in to keep it aerobic, and improve the ratio of stinky compounds to water vapor released by providing greater resistance to larger compounds like indol, scatol, cadaverine, and putricine. If it isn’t quite enough to keep things fully aerobic, I may also add some copper sulfide and baking soda to stop the production of additional stink, and see if that helps to manage smell while it dries out.

As I said, though, the devil is in the details. We’re shooting for a middle ground that may not actually exist, or just may not exist where tyvek would get us.

Also worth noting that if the plan was to burn the poop, this is probably not the best approach since you would just end up with a bunch of shit-smelling tyvek that you couldn’t burn.

Insert namewrote:

Tyvek and silica packets?

Silica packets or gelling compounds would draw moisture out of the poop, but then retain it in the package more effectively, and actually prolong the drying process since it would retain moisture longer. Gelling compounds are for when you are committing to anaerobic and you want to render the mass relatively inert as fast as possible. Unfortunately, relatively inert is not fully inert, so them wag bags still stink.

Why not just add a scoop of active charcoal to absorb all those stinky volatile compounds. I like the idea of a middle ground, of course your poop tube would also have to be permiable.

Creating a mini oven with a black poop tube could also work, it could reduce the quantity of bacteria significantly it if internal temps can be raised to 70c. 

Having removed Tyvek over the top of a completely rotted out ( sheathing and studs) walls before I can let you know that the expected outcome is not going to be what you had hoped.  Take a creamy shit sandwich in one and leave it in the sun for 2 weeks and guess what....still going to be a creamy sandwich inside.  You are also using a material designed to be extremely durable, which also guarantees you will be leaving a mess for the next generation.  There is no recycling/upcycling/composting option for Tyvek coated in shit.

I know companies make things with no consideration for the after effects of such use accumulates.  We as individual users should hopefully have enough common sense to recognize when we are doing things that are extremely eco-unfriendly.  Shitting in a tyvek bag is right up there with burning plastic in my mind as having absolutely no regard with how your actions effect your community and planet.  Try harder....

Kevin, I appreciate the concern for the environment, unfortunately however there is no environmentally friendly way dispose of shit smeared anything. It's biological waste at that point. Commercially, it's incinerated, if you live in a rural area maybe you can take your shit filled paper bags home and bury them but that's not a realistic solution. Tyvek is no less environmentally harmful to the environment than wag bags. 

There are compostable PLA sealable bags that exists, these could be a viable middle ground but I would be concerned about their integrity on a wall. A Hot moist environment is exactly the conditions PLA is industrially composted in and disposal would be no different to the paper bag. 

And when it comes down to environmental impact scale is critical, thousands of little tyvek bags a year might sound like a lot but it's a drop in the ocean relative to all the sanitary products out there. 

that guy named sebwrote:

Kevin, I appreciate the concern for the environment, unfortunately however there is no environmentally friendly way dispose of shit smeared anything. It's biological waste at that point. Commercially, it's incinerated, if you live in a rural area maybe you can take your shit filled paper bags home and bury them but that's not a realistic solution. Tyvek is no less environmentally harmful to the environment than wag bags. 

There are compostable PLA sealable bags that exists, these could be a viable middle ground but I would be concerned about their integrity on a wall. A Hot moist environment is exactly the conditions PLA is industrially composted in and disposal would be no different to the paper bag. 

And when it comes down to environmental impact scale is critical, thousands of little tyvek bags a year might sound like a lot but it's a drop in the ocean relative to all the sanitary products out there. 

Seb, your completely wrong on this.  You can use paper bags, seal them in your used water bottles, then empty the bottle and recycle it.  You can poop in plastic bags, which will break down into microplastic within a decade.  Tyvek is much more durable, bury a poop in a tyvek bag in your back yard and you will have a fosselized turd in a tyvek bag in a decade.

Also your justification of use compared to other items doesn't factor in that we all have to make these small decisions on a daily basis.  Yes, our individual environmental footprint may be small, but the cumulative effect of all these tiny, seemingly insignificant decisions does make a difference.  As does a culture that shows it values environmentally sound decision making.  

Kevin Strickerwrote:

Seb, your completely wrong on this.  You can use paper bags, seal them in your used water bottles, then empty the bottle and recycle it.  You can poop in plastic bags, which will break down into microplastic within a decade.  Tyvek is much more durable, bury a poop in a tyvek bag in your back yard and you will have a fosselized turd in a tyvek bag in a decade.

Tyvek is just HDPE it's pretty durable but there are many routes for it to break down in various environmental conditions.

 https://link.springer.com/article/10.1007/s11356-022-23382-1

Also your justification of use compared to other items doesn't factor in that we all have to make these small decisions on a daily basis.  Yes, our individual environmental footprint may be small, but the cumulative effect of all these tiny, seemingly insignificant decisions does make a difference.  As does a culture that shows it values environmentally sound decision making.  

If you poop on big walls daily I envy you. Most people who do climb bigwalls will do less than half a dozen over their lifetime. There are significantly more pressing and impactful environmental decisions we can make everyday. 

I didn't want to shut down the conversation at the start with my environmental concerns, because in addition it just doesn't make sense scientifically.  I had hoped that others in the community might at least broach the subject, but it seems like maybe there are not many climbers who also study building science.  We use dyneema in our climbing gear because it's extremely strong and durable.  We don't need to poop in dyneema bags unless we are going to be re-using them.  This should be common sense.

You might study building science but I study material science, specifically self reinforced composites (tyvek is an example of this). HDPE isn't UHMWPE (dyneema), HDPE is what most water pipes are made from (you know this of course). As an aside HDPE has relatively little environmental impact both in production requiring less energy and water than most other polymers and in general being highly innert and non-reactive to biology, and with the potential to be derived from biological feedstocks. 

While microplastics are a concern, this field is still in its infancy and we don't know enough to say anything definitive. 

Anyway, I say shit in a paper bag, add some activated charcoal, put it in a matte black TPU dry bag air tight with a one way valve that allows it to vent water vapour and the like but keeps it water tight. Internal temps of the bag will reach above 70c (needs to be verified) dry things out and pasteurise the poo. No good for cloudy walls but suitable for most valley climbers. We just need better poop tubes. 

Just hang your poop tube of choice well below your haulbag on a tether. That way when it crashes into the wall the smells get knocked out. It's science.

Steering this toward back to the technical discussion, I proposed putting a paper bag turd burrito into a tyvek bag inside of a mesh bag, making this similar to using a water bottle. The environmental advantage would be that the tyvek bags take up less space so it might be more reasonable to store and reuse them if you empty them and wash or let them air out in the sun between uses (tyvek is machine washable). Then you could also reuse the water bottle instead of turning it into trash.

Basically, this approach is more about a middle ground between paper bag in a mesh bag, vs plastic bottle stuffed with wag bags. Maybe less stink, and maybe less environmentally impactful if the bags are reused, especially if it leads more people to use the paper bag approach ;)

Note that this approach would not work well without a paper bag liner because the paper is needed to help the moisture in the feces evaporate so it can escape, and to prevent condensation from blocking the pores in the tyvek.

that guy named sebwrote:

Why not just add a scoop of active charcoal to absorb all those stinky volatile compounds. I like the idea of a middle ground, of course your poop tube would also have to be permiable.

Creating a mini oven with a black poop tube could also work, it could reduce the quantity of bacteria significantly it if internal temps can be raised to 70c. 

I’m local, so I will mostly big wall in the winter when fewer people can schedule around the weather. In the summer a black tube might be ok, or it might just simmer things at a nice 150F most of the time, once you account for thermal mass and colder nights. Probably a separate lot of sciencing.

I expect that for winter climbers at least the high surface area of individual bags will be important due to the relatively low vapor pressure. Some of the stinky compounds are “slippery” and therefore would not be captured by activated charcoal, but it would definitely help with many components of the smell.

Jim you may be on the right track and I can certainly appreciate the scientific approach!

Just to relate my experience, I fall into the anerobic camp. I use regular wag bags inside the Metolius poop tube. Despite the cheekiness of my above comment, hanging the tube ~15 feet away below the haulbag has worked well for me. It's far enough that air flow wafts any errant smell away. I think if you are "venting" it would be even more important to keep your diabolical creation a safe distance afield.

jt newgardwrote:

Jim you may be on the right track and I can certainly appreciate the scientific approach!

Just to relate my experience, I fall into the anerobic camp. I use regular wag bags inside the Metolius poop tube. Despite the cheekiness of my above comment, hanging the tube ~15 feet away below the haulbag has worked well for me. It's far enough that air flow wafts any errant smell away. I think if you are "venting" it would be even more important to keep your diabolical creation a safe distance afield.

Thanks, yeah, I think current systems are mostly ok, but with significant drawbacks at times.