Archive | El Punto Coyote RSS feed for this section

Buried, but still beating

23 Nov

268563_165140516886706_7492766_n

“You can never go Home again.”

Sometimes places where we plant our heart are lost to us. We plant our feet, hang our hats, and embed our souls in a place. Then sometimes we have to walk away and let it go. But we never do let go completely. Pieces of us remain, parts of our heart or soul may be buried there, and all we take with us are the memories. Yet those buried hearts still beat. And pump that which connected us to those places through our veins. We still carry them with us.

This is the place where part of my heart still lies. Buried now. But still beats quietly. And sometimes I find myself back there in spirit. If not in person. Just like other places before this, and those places that have yet to receive my beating heart. Funny how we scatter ourselves and leave pieces behind.

Morning has broken like the first morning.....

Morning has broken like the first morning…..

Advertisements

Adobe wall creeps along with a lizard

12 Apr

Adobe wall slowly grows taller

Work on our place has stalled due to construction jobs elsewhere in the desert. We stole one day to lay a few courses of adobe block on the arch, but have several more courses to go before the ramada west wall is done.And we continue to experiment with plasters, as you can see on the adobe wall. They will eventually be chipped off before the ‘real’ plaster is applied.

First cob sculpture: lizard!

With a few hours to spare at the end of one day, and with a bucket of heavenly red clay sitting there shouting at me every time I pass it, I mixed up some of that clay, black volcanic sand, and a couple handfuls of chopped dried grass that we harvested from alongside Terlingua Creek. Bit by bit I added water, played with the cob, and a lizard started talking to me. And now I have a dark reddish brown lizard buddy that is still solid despite drying in the sun for nearly a month. I think he is deserving of a red clay slip to hide the grass clippings and look more elegant. Then I’ll have to find a place to incorporate a vertical block!

 

A new addition to the El Punto family: a 2,700-gallon capacity tank. We’re very happy!

Happy water cistern.

 

 

 

Adobe Test Blocks Again

26 Jan

“A cement mixer is your friend.” We’ve heard this many times from people making their own adobe blocks and concrete for various projects. After mixing components in a wheelbarrow three times in a day, I was lusting after a mixer.

Ed adding components to the mixer.

We finally bought a new 4 cubic foot mixer that was priced as a special from Northern Tool Company during a trip for a family event in Fort Worth. Like most any consumable product these days, it came in a box. We wondered how a good sized cement mixer could fit in a box, but it did. (I questioned if products are now standardized to fit in boxes.)

As Ed expected, the instructions for putting the mixer together were more than inadequate (pidgin Chinese?); some segments were wrong. Because of Ed’s mechanical background and experience with poorly written manuals, he had little problem putting it together. From my experience editing science and technical manuscripts written by non-English authors, I could only imagine. Regardless, it was soon put together all burgundy and shiny, waiting with gaping mouth and hungry for hard stuff; “Feed me!”

One sunny and warm day this week, we decided to try our hand at making adobe blocks with our newest member: Audrey.  (Classic musical cue here) Ed had several five-gallon buckets of adobe mix components waiting next to the front of the mixer:

  • Clay: sourced from a hillside near Cedar Springs area and which has proven to be good clay for adobe blocks (see former post),
  • Sand: crushed and screened recycled adobe blocks that were rejects because they were too high in sand (they broke apart VERY easily)
  • Cement: regular Portland cement
  • Water from our rainwater catchment tanks
  • We have at this time forms for only four blocks.

We began by screening the clay on a 3/8-inch screen over the wheelbarrow. Very little aggregate was discarded after using gloved hands to break up clumps on the screen.  About ¾ of a large bucket of raw clay (before screening) was enough for each batch.

We made two test batches. The amount for each test batch was as follows:

  • Clay: 5 shovelfuls
  • Sand mix: 15 shovelfuls
  • Cement: 2 shovelfuls
  • Water: 5.5 buckets (bucket holds 80 oz.., ergo 3.4 gallons)

Mixing time was a new variable that we also wanted to test based on comments in Gernot Minke’s book (Building with Earth: Design and Technology of a Sustainable Architecture, 2nd edition, pub. 2006). Regarding clay, mixing time was an important influence on mixtures for plaster and blocks/bricks that contained clay. According to tests at the university lab in Germany, extending the mixing time from one to ten minutes enhanced bonding capacity of the clay and water adsorbance in the mixture (1). On the other hand, extending duration to 20 minutes reduced the bonding capacity. We tried two durations: Batch 1, 7-10 min. Batch 2, ~15 min.

Batch 1

Number of blocks: 3 whole blocks + ~1/2 of a block left in the wheelbarrow.

Observations:

  1. Ed started mixing the second batch while I filled the block forms with mix from the first batch.
  2. This mix had a nice slump, probably between the consistency of grout and mortar (2). The consistency was similar to the mixes for blocks made at New Mexico Earth near Albuquerque; loose, but not watery. It is fluid enough to easily fill the form corners without a lot of hand-forming, but not too wet that the blocks crack easily.
  3. As with both batches, Ed added all the dry ingredients first, then added water. With the first batch, he added the water a bucket at a time with ~30 sec of mixing in between, then adding another ½ bucket after mixing for a minute or two.
  4. Because there was not enough mixture for another whole block, I left the remainder in the wheelbarrow to mix with the second batch. It is important to shade the leftovers from the sun to prevent drying too quickly.
  5. Forms were pulled while second batch was mixing. (~12-15 min).

Batch 2

Number of blocks: 4 whole and 2/3 of a block

Observations:

  1. This mix was noticeably drier and grainier than Batch 1. Although the water content added was the same, the difference may have been larger shovelfuls of the sand or clay. Ed discovered that constancy between shovelfuls was difficult to maintain because of trying to scoop components from a bucket
  2. This batch, Ed added all the water in quick succession and then let mix for extended time (~15 min).
  3. Related to #1, the slump of this batch was stiffer and required a lot more time from both of us to push mud into the corners, lightly compress with our hand and also screed the top with our hand. This is a good reason for a looser slump of mud!
  4. More blocks were made from this batch because of the residue left in the mixer from Batch 1 and the unformed mix in the wheelbarrow, also from Batch 1.
  5. Because of the drier consistency (slump), Ed pulled off a form from one of the blocks to fill in with the left-over mix to make the 2/3 block.

Overall, from beginning the first batch to clean-up (tools, mixer, wheelbarrow, hands) was ~ 2 hours.

‘Green’ adobe blocks. Top, Batch 1. Bottom four+, Batch 2.

Comments:

  1. Set-up and clean-up times are time intensive. Ideally, we would like to have a larger volume of materials in big piles on tarps. We ran out of our sand component (the crushed recycled blocks).
  2. This would also facilitate longer production runs (4-6 batches) and consistency in shovelfuls as measurement of mix components.
  3. For clean up, a large shallow pan or stock tank ½ full of water would facilitate efficiency of water and cleaning tools. It would also facilitate wetting the inside surface of the block forms to avoid the mud sticking to the forms.
  4. More materials. Can’t be said enough.
  5. If we can make 4-5 blocks/batch, than we will probably make ladder forms for that many blocks. I also want to get some landscape cloth to put on the ground underneath the forms.
  6. We still need to experiment with adding the water. The second batch had some dry clumps in the bottom of the mixer. Add water a bit at a time, like we did in Batch 1? Or all at once, as in Batch 2? I think this still needs experimentation.

A note on the recycled blocks. These were reject blocks from a project north of us. They break and crumble easily and spall (particles fall off the block when lightly rubbed with the fingers, or as they erode from weather). Consequently, they have very poor tensile and compression strength. We also discovered that plasters do not adhere to these blocks because the granules are so loose (spalling).

Another contribution to their loss of integrity is that they were stored outside, stacked flat on pallets, and with pallets on top of pallets. Most of these blocks that we picked up are being recycled. Those that are stronger are being used in the west wall of the ramada. However, new blocks that we are making and that pass our strength and compression tests will be used for the arched window in that wall.

Footnotes:

    1. Clays are like ‘chemical sponges.’ Clay minerals are colloids with large flat surface areas and carry negative or positive charges on their external and internal surfaces. Thus they have the ability to attract other charged particles, especially many water molecules. Because this attraction is a surface phenomenon, it is called adsorption (which is different from absorption because the ions and water are not attracted deep inside the clay grains).
    2. Slump is commonly the consistency of masonry materials in a specific batch. The fluidity and plasticity of material varies for different applications, such as concrete, mortar and grout. For discussions on slump, visit these two websites: What Is Grout and Slump Testing.

The adobe west wall of the ramada. It’s also our plaster test wall.

 

What’s in a block?

13 Dec

that_shade_of_mud_caveman_359065

While Ed spent two days working on a door jamb at Cedar Springs Ranch (Terlingua), I experimented (like the good scientist that I am) with making my first adobe blocks: solo. All the necessary supplies from El Punto were loaded into the truck to take with us: wheelbarrow, new mortar hoe (like a garden hoe, but with holes in the blade), two block forms (a double and single), a bucket of lime, gloves, mask, and two empty buckets. The other constituents – sand, clay and water – were yet to be gathered. And I had a source in mind: my favorite black arroyo bottom.

Dark sand in arroyo bottom.

An arroyo runs through Cedar Springs Ranch carrying tons of black volcanic particles: sand.  After a rain it all glistens like a black milkyway poured from an invisible bowl. The black or dark gray contrasts nicely with the rest of the desert floor which is dull white to light beige, and provides a wonderful contrasting backdrop to wildflowers blooming in or next it. I’ve always wondered what adobe blocks would look like made from this sand and this was an opportunity to find out.

Know Your Mud

I disregarded the general rule of thumb when evaluating any potential source for making adobe blocks. Know the ratios of sand, clay, and silt in your native soil. The best evaluative technique is to do a water and jar test, or soil hydrometer test. Fill 1/3 of a quart glass jar with the mixture (sifted and free from rock) and bring up to 2/3 volume with water, leaving about an inch of air space at the top. Add a drop of detergent, which acts as a surfactant and helps separate particles. Cover and thoroughly shake for several minutes. Let sit undisturbed for at least 24 hours to allow the contents  to settle into layers (sedimentation).

Sand settles at the bottom within a matter of minutes. Silt settles on top of sand within three to four hours. A color and size difference between the two can usually be seen and measured, unless the mix contains little silt. Clay can take days to settle. I usually wait for the water to appear relatively clear. Any debris floating on top of the water is organic matter.

Unlike the loamy forest and garden soils I was used to in the Pacific and Atlantic northern areas, the soils here in the Chihuahuan desert are characterized by higher ratios of sand to clay with little organic matter. It may even have lime in it from abundant limestone. Silt is usually associated with river or stream beds. But since this entire region was once the bottom of an ancient seabed, silt can be found at various levels in all soils here.

Soil types

Soil types

After the sedimentation process, measure the depth of each layer of soil particles.  You can then determine the percentage of sand, silt, and clay in your mix. For example, if you have a 1/2 inch deep layer of sand on the bottom layer in the jar, and the overall depth of the soil is one inch, then your mix has about 50 percent sand. For all practical purposes, the ratio of sand to clay is the most important, but does not have to be exact for making adobe blocks. In other words, a window of margin is unavoidable and practical. Regardless, the clay content should not exceed 30% (or ~ 1/3 of the total ingredients) and the sand should never be less than 50%. Various opinions cover silt content, but most recommend keeping it to a low percentage, less than 25%. Strong blocks can be made from 60-75% sand and 25-35% clay.

Ribbon Test

As one gains more experience and becomes familiar with different soil types, the ball or ribbon test is a quicker way to evaluate native soils. The ribbon test is performed by kneading a ball, slightly larger than a golf ball, of wet soil in the palm of the hand. The soil should be kneaded with the fingers until it has fairly uniform wetness throughout. With the thumb and fingers, work the ball and form a ribbon.

The following guidelines can aid evaluation of the soil in the ribbon:

  • If the ribbon is long, flexible, and can sustain its own weight, it is primarily clay.
  • If ribbon is weak, breaks readily, but forms a ball which withstands much handling, it is a clay loam.
  • If the clay loam is soapy or slippery feeling, and appears powdery when dry; it is a silty clay loam.
  • If the clay loam has lots of visible sand, it is a sandy clay loam.

Now, if soil will not form a ribbon and presents a broken appearance:

  • If wet soil is friable, somewhat gritty and sticky, and the ball handles without breaking, it is loam.
  • If the dry soil feels soft and floury, when wet it feels slippery, and the ball does not break, it is a silt loam.
  • If sand is visible and the ball cannot withstand handling without breaking, it is a sandy loam.

Obviously, if the soil is loose and single grained, if individual grains can be easily seen, and the aggregate ‘ball’ crumbles when touched, it is sand.

I did a quick ball and ribbon test after wetting a handful of the black arroyo soil. I let it sit wet for about five minutes and then worked it in my hand. The ball was gritty and slippery at the same time. But I could not differentiate if the latter was attributed to clay or silt. So I did the third way to evaluate soils for making adobe blocks: I made some test blocks.

Let’s Make Blocks!

Sand and aggregate convey strength to adobe block and clay is the binding agent, the ‘glue’ blinding all the sand and aggregate together. Because we plan to use semi-stabilized blocks (for weatherization) for most of our structures, I added a level shovel-full of cement to a five-gallon bucket full of the dry arroyo mix in the wheelbarrow. I added water and mixed well, recalling my instruction on mixing cement and mortar several decades ago when building my Maine cabin. My mix had a wetter consistency than what Ed usually uses for his blocks. I remembered that Helen, of New Mexico Earth Adobes (Alameda, NM), explained that their adobe mud is poured slightly wetter than what we have seen elsewhere. The mud is pliable, flows into the four corners of the molds and requires little to no packing or floating on top. When adobe mud is too dry, it is not pliable, requires hand packing, and the block may cure with a honeycomb effect (voids in the block). The wetter mud can set up in the forms for an hour or more before the forms are pulled off.

One important task I neglected to do before pouring the mud into the forms was to thoroughly wet the forms. I paid for this negligence later; the mud stuck to the inside wooden surfaces. I had to use a large knife to coax the drying block edges from the wood and they cracked in the process. After that, I now soak the molds in a trough of water right before using.

The next morning when I inspected the blocks, I was disappointed when they crumbled easily in my hand. Too much sand and not enough binder; clay. The slippery texture of the test ball and ribbon was mostly likely silt. So it was back to the adobe mixing for another try. This time, I needed a good source of clay. I planned to recycle the three blocks I made providing sand by adding it to a mix of a higher percentage of clay.

Ed and I went out on the Kawasaki Mule with an empty five-gallon bucket and scouted for a source of clay. Not an easy task in an area that is mostly limestone, sandstone, gravel and sand. But we did come upon a small hillside that looked promising. After returning with 3/4 of a bucket full, I went to work. With the two forms, the double and single molds, soaking in a trough of water, I screened the bucket full of new mix with a 1/4″ screen on top of the wheelbarrow. I noticed that exerting some pressure on the aggregate pulverized it into smaller pieces. Surprisingly, only a small amount of large aggregate was discarded and the colors were interestingly dark brownish-red to rosy pink. Even small flat and angular crystals could be seen. ‘This should be interesting,’ I thought to myself.

I pulverized one of the volcanic sand blocks in with the newly found clay, added a half shovel of lime and water, and began mixing. The wet color was an interesting rosy color despite the added dark sand and gray cement. When it looked well mixed, I retrieved the two forms to lay on cleared gravel and shoveled in the adobe mud, although the mix only filled two and 1/2 molds (2.5 blocks). I was pleased at how well they filled the mold corners and edges with minimal hand packing, and the tops were like poured soft ice cream.

Small cured test brick from new clay source.

After an hour and 1/2, I pulled off the forms easily and the blocks retained their shape well. The forms were washed and brushed clean to dry for the next batch. If these turned out good.

The next morning was a treat when I examined the blocks. They were solidifying nicely and felt dense without any crumbling. And they were a beautiful light rosy blush. I immediately decided this was going to be a good mix and it was time to get more of this clay! We returned to the same hill with two five-gallon buckets. I screened one bucket at a time and added one of the crumbly blocks from the arroyo (which were now getting more difficult to pulverize) to each batch. Ed helped me mix this time (tough on my low back) and we made three blocks from each bucket of new clay. We let the blocks sit in the molds for an hour before pulling off and returning to their water bath. I think they would have done better to sit for another 30 minutes before pulling the forms, so we let the last batch sit longer.

We stayed the weekend at Cedar Springs with Randy and his dogs, enjoying company, sharing meals and stories around the campfire. Before leaving, I placed the blocks on their edges inside the large metal building to protect them from weather and animals. We retrieved the blocks a few weeks later (Thanksgiving weekend) and stacked them under the the ramada at El Punto where they will have the special privilege of being incorporated into the arched window. They are still strong and beautiful; an aged beige with a rosy blush, and I can’t wait to make more.

One helpful addition to the adobe tool set would be a cement mixer!

Blocks from the new clay source.

Zen View

6 Mar

The ramada columns are completed. The adobe wall is next on the agenda for the ramada. However, that project has been pushed down on the priority list by the urgent need for a storage shed!

Ramada

Listening to the stones

26 Feb
view of ramada

First completed stone column

Ed is learning to listen to the stones, and the conversations have been constructive. While spending two weeks at El Punto in Big Bend, the goal was to progress on the ramada. The metal roof has been installed and now allows for shade, even shelter from rain…. when it does rain. The the fun part: constructing the stone columns around the corner posts of the west wall.

That begins with collecting stone; lots of it. Working with stone, or rock, requires a mindset of intimacy with the goal, methods and materials. One stone or rock does not fit all. In other words, for the purpose of encasing the metal posts in stone, round rock would not be the best choice. Nor big rock or stone of any shape. Keeping in mind how other components of the walls will be integrated together, a large mass of rock would be unnecessary and uncomplimentary to the adobe blocks that will infill between the corners posts. Small flat stone, however, would be more practical and aesthetically pleasing. With that in mind, the builder looks for stone that will, well, ‘work’ with the goal.

Form for rock columns

Beginning the stone column with steel form guides.

Ed welded a steel collapsible form to serve as a guide for the four corners and four lines of the square. The steel bars are held together by shorter bars that can be screwed and unscrewed to aid simplicity of erecting and disassembling the form. Then he collected stone from the sides of the roads and hauled them to the site where they will be used. In rock and stone work, it is imperative to have more material than you think you might need. Inevitably, you will need more than you think you did, and the more rock or stone you have, the  more choices in pieces that fit into the overall puzzle.

Initinally, Ed intended to use as little mortar as possible so that the stone column would look as if it was dry-stacked (stacked rock or stone with no mortar). However, the small size of the stone and the column necessitated using more mortar to keep the stone in place. Regardless, one can recess the mortar so that the overall appearance is more rustic rather than typical stone walls and mortar forming a flush exterior surface.

As Ed discovered, some days the stones are silent. They don’t ‘speak’ to you, and there’s no smooth zen in finding the right stones to fit the right places. Then it is all well and good to just walk away for the day and start anew the next.

In the desert sun, the mortar can dry quickly, which is undesirable. The ‘sticky’ property of mortar is a function of ratios between sand, water, and a binder, such as cement or lime. When water is added, a chemical reaction occurs and it quickly ‘sets’ (becomes hard). Thus, during hot weather, or in the sun when evaporation rates are high, speed is the essence. A trick we learned from Jerry, a musician by trade that builds stone houses for a hobby, is to brush water onto the rock or stone, or even dunk the rock in a pail of water, before setting it onto a bed of mortar. This helps bind the mortar to the stone much better than if the stone surface was completely dry.

Ed commented after completion of the first column:

Column completed.

Completed column and comfy chair awaits.

“I am pleased with the profile and texture. Not often I am pleased with a first effort on something this intricate. Starting small sounded like a good idea. Lesson one from the stones is that small stones demand exact placement. An eighth inch error on a big rock disappears in the project. An eight inch error on a two inch stone sticks out like a sore thumb.”

One more column to complete and then he can begin constructing the adobe wall that will span between the two columns. We already have about three dozen blocks, some salvaged and some we made. He mentioned on the phone today that he will start making blocks with the new two-block mold he made before heading down to Big Bend this trip. He also reported that the three blocks made from the black volcanic sand and clay obtained from the Cedar Springs area dried to a lighter color than we anticipated. The final wall should be interesting with the hodge podge of blocks made of different sources of clay and sand. But that’s part of the fun of it.

I certainly look forward to my next opportunity to sit in the comfy chairs under the roof of the ramada and watch the sun rise over the Chisos and Christmas Mountains. Also, I miss my old friend Hen Egg Mountain (which was originally named Terlingua Mountain, but that’s for another post). In fact, I might just hang a hammock in there and sleep out in the desert without walls.

Next project on the ramada is adding a gutter to the west side of the roof and placing a small catchment tank nearby. The south side will incorporate an outdoor shower with rock and glass walls. This will replace the black solar bag that hangs from a rafter in the front of the ramada in the photograph. The design is my job, and I have several ideas in mind. First, the exterior wall will be semi-circular. Also, the shower water will be reused to irrigate a few plants next to the ramada. To roof or not to roof, that remains a question.

So El Punto Coyote continues to evolve. Hopefully in a way to allow us to live, but with as little impact on the surrounding terrain and biota as possible. I wish for all of us to be a sustainable community, no matter how small we are.

Stone Zen

9 Feb

Something about working with stone that just soothes the head while beating the body. Maybe it’s the satisfaction of combining physical labor with creativity. And accomplishing something, usually functional and practical. Sometimes, it’s only aesthetics.

I had learned stone work in Maine from just doing it; trail and error. Maine’s largest crop is rock. Pick up all the rock in one location and more will sprout within a short time. Walk through the dense woods and you will find old rock walls over 200 years old. Most foundations of earlier houses and barns were made of rock. The corner of my cabin sat on granite ledge; that is one big rock. With rock everywhere, it was a cheap building material. For the price of hard labor. But that didn’t stop me.

I built a retaining wall along two sides of the cabin with steps made of railroad ties and stone. Incorporated into the corner of the retaining wall was a tall rock garden, filled with herbs, woodland strawberries, and perennial flowers. Stone and I seemed to be a match; our relationship kept me busy and in shape for the many years I lived in the Maine woods.

It’s been many years since the stones have spoken to me. Until my routine visits to Big Bend area. I began bringing home small rocks to scatter around the house, in the small vegetable garden, in front of the house. Then we started getting serious, the stone and I. We’ve brought back to El Punto many loads of rock. The first project was the fire pit, with a large elevated slab nearby to serve as a cooking table. Then another slab near the end of the point overlooking Black Creek Draw for a contemplating bench. Then……

Stone stoop.

From several rock scavenging runs, I began to build a rock compost pile. That was interrupted by an impulse: the outhouse needed a flagstone stoop. Beginning with narrow stones, the perimeter of a semi-circle took shape. With a rough shape in place, I began gathering flat stones to fill in. Like a jigsaw puzzle, stones were placed, moved, wiggled, removed, replaced until finally the interior of the semi-circle took shape. I even robbed the beginning compost bin for the right rock. A chip here, a wiggle there, it was done.

Leftover fine aggregate that Ed had screened from a wheelbarrow of mixed roadbase to use for adobe block mix filled in between the stones. After sweeping the stones of excess grains, I walked around on them to help settling. I knew that more aggregate would have to be added, but that’s part of the process. You don’t wipe your hands and walk away thinking it’s all completely done. Stone projects age like fine wine, and sometimes you have to add a bit here or there.

Ed shares my penchant for rock. At his suggestion one very cold morning, we bundled up and took the truck out to retrieve a load of wonderfully flat stone that had been chiseled and uplifted by the road grader. The pile ended up near the ramada for inclusion in the south wall and the floor. Small flat rock will also surround the metal posts on the west side.

Perhaps the compost bin will be finished. Some time.

%d bloggers like this: