[GSBN] Hand Compressed bales

[martin hammer]

> (Note: I sent this three days ago, but just realized I sent it to myself (!!),
> so I¹m resending.)
> 
> Hello Andy,
> 
> I¹ll add to this from my work, along with Andy Mueller, with manually made
> bales in Haiti.
> 
> My experience with Darcey and manual bales in Pakistan transferred very well
> to the environment in Haiti.  We had a steel compression mould fabricated
> similar to the ones PAKSBAB uses.  After a fruitless search for a farm jack in
> Haiti (though I was told they exist) we imported two from the US.  We
> considered using car or truck jacks commonly available in Haiti, but couldn¹t
> see how they could work well.  Farm jacks (48² is a good size) work very well
> for this purpose.
> 
> The compression mould design Darcey gives you is a great start.  You may or
> may not see ways to improve it for your circumstances after using it.  Making
> a compression mould offers the opportunity to make the bales any size.  I
> think the 1¹x1¹x2¹ (30cm x 30cm x 60cm) bales are just right for Pakistan and
> will work well for you in Lesotho, which appears to have a climate similar to
> northern Pakistan.  That size bale is thick enough to provide good insulation
> (R-24?), but small enough that it doesn¹t consume too much straw and is easier
> to transport and handle, and keeps the cost down.  It¹s a good balance.
> Haiti¹s tropical climate doesn¹t demand the same level of insulation (though
> insulated walls help keep the interiors cooler, or warmer in high altitude
> winters), and we considered making the bales even smaller.  We might try
> 10²x10²x20² bales or even 8²x8²x16² (a standard concrete block dimension that
> is the predominant building material in Haiti).  But each time we discuss this
> we speculate the wall system will be too unstable, even if only during
> construction, and it would increase labor in handling.
> 
> Whatever size you choose, having a 1:2 ratio of width to length is important
> for turning corners.  A 1:1 ratio of width to height allows bale orientation
> ³flat² or ³on-edge² in the same wall, if exposing or not exposing the ties has
> an advantage of disadvantage.  The small footprint of these bales requires
> consideration of the wall system you may not be accustomed to, both during
> construction and for its performance as a finished system.  I believe South
> Africa is in a relatively low-risk seismic zone, but the system still needs to
> be well-designed for all of its structural demands.  The small footprint, with
> minimum 8 ft. wall height, seems to require a system of through-tied external
> pinning, both during construction (after four courses the stacked bales become
> too unstable) and for out-of-plane stability as a finished system.  Bamboo
> works very well for this purpose, though wood or other materials can be used
> if bamboo isn¹t available.  Of course plaster type and whether it is
> reinforced or not is an important part of this as well.
> 
> Finding the right twine can be a minor challenge.  Something that is strong
> enough and not too costly.  In Haiti we¹ve brought in US poly baling twine, or
> used poly twine in Haiti that is four times as expensive, but will next
> investigate sisal twine that we know is made in Haiti.
> 
> Regarding density I would aim for a bale weight of 7-8 lbs/cu.ft.  So a
> 1¹x1¹x2¹ bale would weigh 14-16 lb (6-7 kg).  You can judge by feel if you
> want to make them denser.  I looked at my data on the relationship between
> field area, loose straw volume, and compressed bale volume but it¹s not adding
> up.  I¹ll have to study it further, but I remember about a 6:1 volume ratio of
> loose straw to compressed bale.
> 
> The Haitian men who have made our bales developed a technique of folding a
> fist full of lengths of straw into thirds and pressing these clumps of folded
> straw into the compression mold.  Three side-by-side per layer, and
> alternating the direction of each layer.  In the early Pakistan buildings we
> were simply taking large balls of loose straw and stuffing them into the
> mould, but it sounds like that has changed based on Darcey¹s description of
> ³sausage-like bundles placed side-to-side in the mould².  That sounds similar
> to what I described in Haiti.  Making the bales with smaller folded clumps
> yields a good quality bale with few wild ends of straw and provides great
> ³flakes² for filling voids.
> 
> One other opportunity we took advantage of in making our own bales is to
> ³cast² 2x4s into a number of bales for the top course.  After the bales were
> installed the roof bearing plates fit right into the notches, with no void or
> stuffing required between the plates.
> 
> Collecting and drying straw for the bales in Haiti¹s climate has been a
> challenge.  It depends on the weather at the time of post-harvest.  The straw
> was cut and dried on concrete slabs that are normally used for drying rice.
> There can be a week or more where it rains once a day, and it can be a
> struggle to dry the straw and keep it dry.  Storage for either dry loose
> straw, or finished bales can also be challenging.  Not to say these aren¹t
> challenges worldwide for bales, but the tropical climate ups the ante.  All
> that said, we found it all manageable, and that there is a dry season in Haiti
> to mates well with harvest times.
> 
> Another issue to contend with is the price of straw.  I don¹t know how
> valuable a commodity it is in Lesotho, but initially you will likely pay the
> lowest market rate.  In both Pakistan and Haiti, once it was learned the use
> of the straw, there were often attempts to raise the price.  There is another
> related issue, of the current utility of straw in your location.  Animal
> bedding, low-grade animal feed, rural building material (thatch roofs, earth
> plaster ingredient) are the most common uses as I understand it, of un-baled
> straw in developing countries.  In general I believe straw for bales in
> buildings is at least as high a use as any of those, but it has to be
> considered in terms of the overall supply and demand of straw.
> 
> Also, in Haiti I was surprised to learn that the common practice of burning
> straw serves two purposes.  To rid the field of straw to allow the next
> planting, AND to create ³biochar² that reintroduces nutrients into the soil.
> I don¹t know why I had never heard of this before, and I wonder if this is
> common practice throughout the world.  I was told by our land owner partner
> that if we developed the ongoing practice of taking straw from the fields to
> make bales, the farmers would need to add other fertilizer (compost, manures,
> or industrialized), most of them at a cost.  The land owner did say that the
> biochar is not a complete or high-grade fertilizer (manures are the best) but
> it is still an important part of maintaining healthy soil in Haitian
> agriculture (it supplies potassium, but not nitrogen).  Of course one should
> also take into account the negative effects on air quality when massive
> agricultural burns take place, and that might be reason enough to discourage
> or prevent it.  Part of our work is to implement the use of urine diverting
> dehydrating toilets, and use urine (diluted, great source of nitrogen) and
> dehydrated solid waste as agricultural fertilizer.  This could reduce if not
> solve the problem I described.
> 
> There are photos of our bale making in Haiti at www.builderswithoutborders.org
> (see Project Photo Gallery).  I have others if anyone is interested.
> 
> Andy, I hope this helps, and I¹m sure it¹s more than you bargained for.  When
> you go upstream from the industrialized bales most of us are accustomed to it
> opens up other territory.  Andy Mueller was also intimately involved in both
> the fabrication and installation of the bales, so Andy please feel free to
> comment.
> 
> Best regards and best of luck with your work.
> 
> Martin Hammer


On 11/3/11 7:29 AM, "Andy Horn" <andy at ecodesignarchitects.co.za> wrote:

> Dear Darcey & others
> Some time back in the Dec 2006 Last Straw there was an article about the work
> of Darcey Donovan and Greg Zaller in an earthquake struck area of Pakistan,
> where they used hand compacted bales using car jacks to make their bales for
> some community projects.
>  
> We have a Hospital project in the icy highlands of the small mountain kingdom
> of Lesotho, where the locals are growing wheat (organically) and harvest by
> hand. We intend to build using straw bales and I am looking specifically for
> information about how best to make and utilize a hand compactor.
>  
> We did already make up a simple timber mould simply to establish the quantity
> and hence cost of the supply of the straw that we would likely need to bale
> with. We used a hacksaw (with a fine steel cutting blade) to cut the straw,
> placing the cut ends to the outside and thinning ends towards the inside
> alternately so as to lay it in a regular fashion. We did not try use a car
> jack as at that stage we were just looking at quantities. The locals sell
> their straw in bundles for roof thatching. We found that it will take
> approximately 20 of their bundles to make a single bale.
>  
> In order for the idea to be replicable we need to keep it as simple but
> effective as possible. There is a local metal worker who could weld up a mould
> for us and I am sure we can lay our hands on some car or lorry jacks. I have
> never been down this road before and have no idea of the finer technicalities
> of making your own bales.
> -         Are there certain car or lorry jacks that work better than others?
> -         how to best design the mould?
> -         how best to lay the straw into the mould?
> -         What kind of level of compression is one looking for and how does
> one establish the right level of compression?
> -         How to get this as efficient as possible?
> -         What can go wrong?
> -         etc etc
> I did already try follow John Glassfords link on his web site that he
> mentioned (see his mail below) in regards to looking at this for th Haiti
> project, Thanks John Š.but would appreciate much more specific detail.
>  
>  
> The other thing that came up was the possibility to make thinner bales for
> internal walls Š.but again I have had no experience with this.
>  
> 
> Any input would be hugely appreciated.
> 
>  
> 
>  
> 
> Many thanks
> 
>  
> 
> Andy Horn
> 
>  
> 
>  
> 
> 
> G ' day Balers
> 
> Sounds good to me bales for Haiti. Remember it was an earthquake and if you
> have not seen the work been done by Darcy Donovan here is a story posted some
> time ago now:
> 
> (Just scroll down)
> 
> http://glassford.com.au/main/?paged=5
> 
> Also you must all have seen the video of the test done in Reno:
> 
> http://imedia.unr.edu/shakertables/straw_bail_house_test_270.mov
> 
> I love the hand baler that the Pakistanis are using.
> 
> Seeing there is high unemployment in Haiti and if there is any rice straw in
> the paddocks then the hand balers would work.
> 
> Anyone know how Darcy is going last time I heard Darcy was still in Pakistan?
> 
> Kind regards
> The Straw Wolf
> Huff 'n' Puff Constructions
> http://www.glassford.com.au
> 61 2 6927 6027
> In Australia (02) 6927 6027
> 
> Mountains of the Moon 2011
> http://www.mountainsofthemoon.org
> 
> 
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