TRASH ROCKS -- Eliminate Unrecyclable Trash

 by Thinkenstein
Featured
TRASH ROCKS (13).jpg
TRASH ROCKS (12).JPG
To make a trash rock, a sack is first sewn out of fishnet.  It is filled with trash and plastered with cement.  The resulting shells are unique in shape and look very natural.  Trash rocks are an esthetically pleasing and constructive way to eliminate trash.

Trash rocks can be used as benches, tables, sculpture bases, landscape accents, and walls. A family living in one location over time could build a castle out of their trash. I would expect trash rocks to have good thermal insulation, useful in both hot and cold climates.

I'm big into recycling and built my whole house out of recycled nylon fishnet and cement, a material I call nylon-cement. For many years I eliminated all my trash right at home using trash rocks. 

Ideally, I would like to see a chemist develop a way to recycle some of our plastic trash and make a mesh material like fishnet out of it that could be plastered with cement. 

Recycling is all about mining trash; converting waste into something useful. If we separate our trash first and put it into separate trash rocks we would know where to look for specific recyclable materials in the future when we need them.  In the meantime, why not enjoy living around all the trash we generate? 
 
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Step 1: Scoring the Fishnet

TRASH ROCKS (14).JPG
Many years ago I bought new fishnet by mail from a fishnet manufacturer. That seemed fairly expensive at the time; $6 a pound, I believe. I wouldn't be surprised if it is double that now, or more.

Then I found the free fishnet mother load of all time right under my nose, the StarKist tuna factory. They were very helpful to me in saving used fishnet that the boats wanted to get rid of. Discarded netting is a trash disposal problem for the factory, so we helped each other out.

After getting it home, the fishnet was opened out, cleaned off, rolled up and stored outdoors. It smelled "fishy". Given a month or two of exposure to rain and air it was completely user-friendly. Fortunately, I live in the country, where I can do this without offending the noses of neighbors.

Good luck finding a source of your own. Fishing ports and fish farms are good places to start looking for used fishnet. Ready-made trash sacks that can be plastered with cement should be available for this idea to really take off. Sewing your own sacks allows you to make different sizes of trash rocks, but ready-made sacks would save some time and effort.

http://agriculture.exportersindia.com/aquaculture/fishing-nets.htm This is a link to manufacturers of fishnet. Most are in the Orient.

http://www.thomasnet.com/nsearch.html?cov=NA&what=Netting&heading=53680203&navsec=prodsearch A search for "netting" on Thomasnet can come up with U.S. manufacturers.
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EngineerJakit says: Feb 22, 2012. 4:48 PM
Man, this is some neat stuff you've made here! Do you think an island could be made out of this stuff, depending on the methods and materials used?
Thinkenstein (author) in reply to EngineerJakitFeb 22, 2012. 6:42 PM
I made a floating cement trash rock once, filled with sealed plastic bottles. I suppose you could make a floating island, or one that rests on the bottom.
EngineerJakit in reply to ThinkensteinFeb 11, 2013. 8:14 AM
Also regarding the floating trash rock, what would your opinion be on making one thats in the shape of a boat hull? if the right amount of bottles were used, it could be done, yeah?
Thinkenstein (author) in reply to EngineerJakitFeb 11, 2013. 2:59 PM
It would float, like a regular bottle raft. Without a skin over it, though, there would be a lot of turbulence in the surface area -- not like knifing through the water with a solid hull. It would be a boat shaped raft is all.
EngineerJakit in reply to ThinkensteinFeb 11, 2013. 3:44 PM
what if you added a few bottles and some cardboard to give it an angled keel along the bottom of the hull? Depending on how it would be fashioned, the fishnet would have to be cut in a pattern to cover the entirety of the boat itself.
Thinkenstein (author) in reply to EngineerJakitFeb 12, 2013. 5:42 AM
Hm.m.m... a boat made out of soggy cardboard and plastic bottles. That sounds unique. Try it out first in a swimming pool, rather than on the ocean.

Here is an idea that I never tried out:

Shape a boat hull upside-down out of sand, like a sand castle. Sift (flour sifter) dry cement over it and trowel it down while still dry. It then soaks up water from the sand and hardens, making a thin shell of cement on the mold.

Plaster that with nylon-cement and let it harden. Tunnel under the edge and remove the sand. Carefully turn it over, without breaking it, (how, I don't know) and line the inside with aluminum cans, pop top openings taped shut, holes against the hull, cemented in place. That might make a cellular flotation layer. Use light-weight cement, possibly with ground up styrofoam filler, instead of sand, to connect the cans.

If you put cans side by side on the floor, you can actually stand on them without crushing them, so this might strengthen the outer shell considerably.

Experiment small-scale and work up.
EngineerJakit says: Feb 10, 2013. 6:16 PM
I have found out that my nearby Wal-Mart sells nylon netting at about $1 a yard. Given the fact that my college doesnt recycle a LOT of plastic bottles, i think i might have a way to test my island plans!
Thinkenstein (author) in reply to EngineerJakitFeb 10, 2013. 8:24 PM
I take it you think of making a floating island. I have heard of a guy in Mexico who did that on some lake. I don't know if you could get away with that in the states. I hope the bottles don't just escape into the water eventually.

Thinking of the Pacific garbage patch, it would be nice if there was some sort of floating recycling plant that could turn the trash into plasterable mesh trash bags and plastic boats to float float it back to civilization.

Some chemistry student could do big help in the plastic trash problem if he could figure out how to convert plastic trash into mesh material that could be plastered.
mcenerny says: Jan 27, 2011. 2:51 PM

terrific "ible" I have been pondering making some lightweight boulders but could not settle on the "filler" - trash bottles, etc are a great idea. I am thinking that in lieu of fishnet, you might use the plastic fencing/trellising that comes in various sizes - or plastic screening??
Thinkenstein (author) in reply to mcenernyJan 27, 2011. 3:34 PM
Fishnet is great because it stretches in all directions. Plastic screening is good for cylinders, but not for balls.

Ideal would be for somebody to figure out a way to recycle some of our trash plastic into a plasterable mesh material.

Used fishnet is a great recycling score, but it's not easy for most people to find. Ideal would be trash sacks all ready for plastering and converting into trash rocks.
uniqueleigh says: Aug 12, 2010. 9:48 PM
I am curious to know if you have any ideas on what could be used instead of the recycled fishing nets. I understand that the netting, because it is nylon, would last longer than an organic material. I was wondering if (for smaller rocks) one could get away with using the net bags that come from the grocery store holding fruit, onions, etc. or even maybe the netting that is used in cast nets. The ones used for catching bait fish. My kids go through them quite quickly and I always have useless ones laying around. I live in Texas near the water and so I am hoping to get a chance to catch someone that runs a shrimp boat to check into getting some old nets but, would like to do some smaller projects until then. Make smaller rocks to go around the flower garden, stuff like that. That would be better with the smaller nets and that way I can still make up some trash rocks until I find the other netting.
Thinkenstein (author) in reply to uniqueleighSep 15, 2010. 10:05 AM
For some projects, fiberglass window screen material works as a substitute for nylon fishnet. It has a finer mesh, and you can make thinner walls with it. I have used it to make a garden retaining wall, and also some minor wall fill-in at a guest house. http://www.instructables.com/id/Garden-Retaining-Wall-plastic-window-screen-and/


tulekah in reply to uniqueleighSep 14, 2010. 7:50 AM
thrift store or dumpster dive for old badminton or volleyball nets.
Thinkenstein (author) in reply to tulekahSep 14, 2010. 12:22 PM
You need a finer mesh to hold a thin layer of cement. With big holes, the cement falls right through.
Thinkenstein (author) in reply to uniqueleighAug 13, 2010. 11:23 AM
Onion sacks don't work very well, because the center part is tightly woven for printing on. The throw nets sound like likely candidates. I prefer multi-filament as opposed to mono filament netting. I don't know how well the mono filament would work. Anyway, it's a good idea to start small and get a feel for it. Play it by feel.
tulekah says: Sep 14, 2010. 8:08 AM
1 how about compacting the trash into near solid blocks or shapes! a bone simple press is a long bar fixed at one end with heavy friend on the other.

2 cover the rocks where they are not going to get stepped or set on with hypertufa-moss mix (martha stewert recipe).

3 set flower pots into the rock, or make depressions, for flowers or ground cover.

4 grottos, hobbit homes, walls made of separate blocks leap to mind.

5 take a drive into the country with friend and gather your building materials by cleaning the roadside.

6 now i know how to make the easter island heads for my front yard!
Thinkenstein (author) in reply to tulekahSep 14, 2010. 12:19 PM
Compressing the trash is a good idea. Black holes come to mind. The idea is to put it to good use, or make it look pretty if you can't make it go away completely.
skiedra says: Jul 1, 2010. 8:54 AM
An fine guide, thanks! I stumbled your tutorial to StumbleUpon, hope this will give you more viewers! ;)
cowscankill says: Jun 23, 2010. 6:45 AM
Floating rock... now that's an idea :D
scmtngirl says: May 10, 2010. 4:33 PM
This is a very clever idea indeed. I have an old crumbling retaining wall made out of wood that needs to be replaced - I've been trying to figure out how to do it inexpensively and out of salvaged materials. It would be interesting to rebuild it out of trash rocks. Thank you for the idea and inspiration!
Thinkenstein (author) in reply to scmtngirlMay 11, 2010. 3:35 AM
I see trash rocks more for free standing walls, benches, and tables.  As retaining walls, plastering the back side of the rock could be awkward.

If you can get the fishnet for the trash rocks, you can do the job with less material just by plastering the earth with a single layer of nylon-cement.

Lean the wall slightly back, so that back pressure from water won't push it outward.  If there is too much back-pressure the nylon-cement will usually crack and leak, thereby relieving the pressure. 
RETAINING WALL (1).JPGRETAINING WALL.JPG
VampiricPie in reply to ThinkensteinJun 20, 2010. 11:35 AM
I'm surprised you didn't use your zipper stairs in the second picture.
Thinkenstein (author) in reply to VampiricPieJun 20, 2010. 1:53 PM
Standard stairs are pretty much OK for slopes that are not very steep. The stairs in the photo probably have some shape variations that are just not very visible in that angle. The zipper stairs really come in handy on steeper slopes. My stairs tend to have variable intersection angles depending on the slope. As they get steeper, they approach 90 degree intersections more.
scmtngirl in reply to ThinkensteinMay 11, 2010. 8:50 AM
Thank you for the lovely pictures. It's hard to believe the first image is not a nature-made rock face! I will post pictures when I find the time to try this out - perhaps sometime this summer. I live in a coastal area (Santa Cruz, CA), so I might be able to score some fishnet from the locals.
rick.leasure says: May 1, 2010. 7:07 PM
Nifty idea! These look good!
I have a couple of questions, though. First, how thick is the cement plaster by the time you're through? Second, have any broken and revealed their hidden contents? Third, how strong are these?

A few more...
What kind of trash do you usually include?
What is styrofoam concrete?
Have you considered crushing glass to use as a concrete ingredient?

Finally, this is a little off subject, but I would like your feedback on it. A couple of years ago, I had some old latex paint and an idea. I mixed the paint with sand. It had the texture of cement and when it dried, it was hard similar to cement, but pigmented with the color of the paint. Have you had any experience with this?

Thanks!

Thinkenstein (author) in reply to rick.leasureMay 2, 2010. 7:09 AM
I would guess the rock walls are about 1/4 inch thick.  None have ever broken, although occasionally you will find cracks.  The net mesh keeps the pieces in place in case of cracks. 

The strength depends a lot on the shape.  A domed rock might support more weight than a flat top rock would, if one was standing in the center.  If they don't support climbing on, I generally beef them up until they do. 

The trash I usually include:  I burn trash paper.  I don't get newspapers, so the volume is not a lot.  I compost organic scraps.  The city collects empty plastic bottles, but there is a lot of plastic trash nobody wants around here, so that goes into the rocks. 

Aluminum gets recycled.  Iron scraps get warehoused as much as possible, for possible future projects, but the less useful stuff sometimes finds its way into a trash rock. 

Styrofoam concrete is like regular concrete except that rock, and sometimes sand are substituted by different size pieces of Styrofoam.   It is less strong than regular concrete, but also a lot lighter.  It is useful for many projects. 

Although glass could be added to concrete, I hesitate to do that because it might break in the future and be dangerous to work with.  I would rather store it inside trash rocks and mine it at a later date if some good use for it came along.   Perhaps a solar furnace might melt it all down and turn it into glass construction blocks, or skylights. 

Latex paint and cement has been tried, and the resulting material is hard.  I don't have a lot of experience with it, but the sample piece I made was very strong.  There are acrylic fortifiers for cement.   Adding latex may give similar properties to the acrylic.  I'm not familiar with latex and sand, except as a way to make a non-slip painted surface. 
rick.leasure in reply to ThinkensteinMay 2, 2010. 10:18 PM
Thank you for your response. So basically, your trash is plastic that you cannot recycle and glass, because you recycle everything else. Makes sense. I was hoping you were able to recycle most of the stuff. Your rocks look good. I'm quite impressed.

Do you have a website that shows other things you have done?
Thinkenstein (author) in reply to rick.leasureMay 3, 2010. 9:42 AM
My website is  www.angelfire.com/in2/manythings .  I think you'll enjoy what you find.  Glad you like the trash rock idea. 
rhino says: Apr 29, 2010. 4:02 PM
Is there a reason I cannot use a burlap bag like the ones you make sandbags with?  After all it will be sealed in cement.
Thinkenstein (author) in reply to rhinoApr 30, 2010. 12:34 PM
Burlap will eventually rot away, so I prefer synthetic fiber material.  People have done experimental architecture with burlap and cement, though, and it lasts a good while, especially if it keeps dry.   I saw a wall with it once, overlapping sacks on horizontal strips of wood.   Toward the ground, where it got rain splash, it had rotted out.  Above, it was still good. 
omnivaal says: Apr 28, 2010. 4:42 AM
Love it. The pics of the weathered ones with plants and moss growing on them look great.
nickodemus says: Apr 27, 2010. 10:55 AM
This is great, using un-recyclables for landscaping. I like the idea of a seating area made of them, and I absolutely love the floating rock idea (last step)! In my opinion your work is the best on the site! Keep it up!
kelseymh says: Apr 22, 2010. 4:07 PM
Just a question.  Since concrete is porous, are there any issues here with the trash inside either rotting, or leaching undesirable solutes out into the local environment?
Thinkenstein (author) in reply to kelseymhApr 24, 2010. 3:51 PM
I suppose a lot depends on what goes in the trash rock.  Any organics that can rot can probably be composted.  If paper rots inside the trash rocks, that probably won't create any problems. 

The decay of synthetic materials, basically plastics, is reduced by protection from sunlight.

Toxic chemical wastes need special disposal.  Unfortunately, we don't have any municipal toxic waste disposal here where I live.  When I do stick any toxic waste inside trash rocks, I try to package it in glass.  Then I cross my fingers. 
kelseymh in reply to ThinkensteinApr 24, 2010. 4:09 PM
Thank you for the response!  I wasn't thinking specifically of toxic wastes, but more about things we don't normally consider "toxic," but which can release stuff over time (e.g., phthalates or bisphenols from plastics).  Your comment about plastic degradation being reduced by UV shielding is right on point.
TheHebe says: Apr 23, 2010. 6:25 AM
Kelseymh:   Nope.  Common enough mistake though!  Concrete is not the same as Cement  - (search ferro-cement for more info or techie talk).   But think of ferro-cement boats - they actually float even when in water over 100 years!

--
Thinkenstein:  Spotted this entry and I thought how the years pass!  Nearly 6 years since I stumbled across your website on your place with this very feature as one of the projects you spoke of there and how you presented your progress into inspiring me to think along these lines also!

I was right tickled to see you on instructables -  you do come up with some very practical ideas with whimsies!   

SALUTE



Thinkenstein (author) in reply to TheHebeApr 24, 2010. 3:41 PM
Thanks TheHebe.   The feedback is the big reward for posting here on Instructables.   So, we go back 6 years.  That's cool. 
jexter says: Apr 23, 2010. 8:54 PM
Nice idea - those are great looking rocks.  As luck would have it, I drive past a business every day going to and from work that I always thought was an internet provider: Net Systems, Inc.  Turns out they make fishing nets!  I'm going to stop by tomorrow and see if they have old nets they want to get rid of, or point me towards a fishing boat that's upgrading it's nets.

Thanks for the inspiration!
Thinkenstein (author) in reply to jexterApr 24, 2010. 3:38 PM
Good luck to you in scoring the net material.  I doubt they will have any old nets to give away, because the longevity of nylon is so great once you keep it out of sunlight.  I hope they can point you toward one of their customers. 
wyldbob117 says: Apr 23, 2010. 11:35 PM
 This is a fantastic idea! I just moved int a house and the last people here left a lot of trash behind. so for the last 2 months ive been trying to figure out how to get rid of it all without spending a few hundred dollers on trash removal. i just have one question. is it possable to use concrete or is that too porous. i know kelseymh asked and i know ferro cement is water proof but it doesent say about concete. i only ask because i have a few bags lying around i was hoping to use but i dont want it to start rotting because of the air flow and have a big mess. thanks.
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