Juan Sebastian Estrada

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since Aug 14, 2013
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Medellin, Colombia
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Recent posts by Juan Sebastian Estrada

Looks like cast anodized aluminum to me. They are definitely durable, but the non-stick properties of the anodized surface do eventually start to fade.
9 months ago
I would be amazed if burning coffee (or any biomass for that matter) produced any more tars than the combustion of heavy hydrocarbons normally found in coal.

As you can see from my details I live in a country where there is a lot of coffee production, and I can tell you from experience two things:

One of the largest producers of instant coffee in this country produces part of their process steam by burning up the spent coffee grounds (after extracting the coffee extract which is then spray dried) in a boiler.

Coffee husks (I know, not exactly coffee grounds) make fantastic fuel and I've seen it used (first hand) in kilns to produce clay bricks, completely replacing coal with virtually no particulate emissions or ash formation.

6 years ago
If I log out and try to buy it just takes me to the permies log in page.
7 years ago
Awesome, bought with paypal. Everything went smoothly.
7 years ago
Imagine my joy when I recently found a wild orchid growing in my property. If you are interested you can read about it here.
7 years ago
I have now identified the orchid from my previous post as a species of Habenaria, a genus of mostly terrestrial orchids from tropical and subtropical regions. They typically have tuberous roots or rhizomes and are perennial deciduous meaning that the plant dies back periodically (kind of like Cypripediums and other temperate orchids).

For me it is very satisfying to identify a plant so that it's possible to learn its characteristics and learn its role in the ecosystem. From what I've read Habenaria plants like wet (they are also called "bog" orchids) weedy/bushy spots. As I described I found this one among the overgrown mimosa thorny plants, so that fits the description quite well, but from what I've been able to observe this isn't a particularly wet place in the property. There is in fact a much more damp area in the lower part which I expect will become a small pond eventually because it's right at the key point in a valley. So either this plant doesn't need or like as damp spots as others or the strategy of letting nature take over in this zone is really helping retain water in the soil. I'll be observant of that.

I created another thread about orchids in permaculture which sadly didn't get as much attention. There and here in other posts I have mentioned that I was an orchid fan before learning about permaculture, so to find a wild orchid growing in my property is even more exciting for me, it really made my day. There are always small gifts of nature that present us with new learning opportunities, I love that about permaculture.
7 years ago
On doing nothing: or rather on not doing.

Some parts of the plot have been overtaken by the mimosa debilis plants that I wrote about before: thorny legumes that are trying to fix my soil while also trying to keep me out of my land . In some parts they mostly keep at ground level, but in some parts they have grown over 1 m tall and have blocked the access to some wild raspberry plants that I like to visit for an occasional treat, so I decided it was time for them to become mulch. I took my machete and went on a chop and drop mission, not really mulching anything, just chopping and letting them drop in place because it's not really enjoyable to move thorny canes anywhere (maybe enough will gather in place to start a hugel bed in the future). I didn't plan on planting anything there yet, but should probably scatter some seeds or plant some trees in place next time, I'm sure they will grow back and I should plant something to outcompete them, I just don't know what yet.

But the reason of this post is to write about not doing (Fukuoka style), which is why the wild plants have started to take over: I have been purposely refusing to mow and "tidy" the place up in spite of my family's urging me to do so. I'm letting the "weeds" do their job even if it means that some unpleasant thorns or grasses may come along.

Around here it is normal to pay someone to come with a noisy gasoline powered weed wacker (with metal blades or plastic line) and mow the place for a reasonably cheap price. I can't bring animals to do the job so I have a less albeit still noisy battery powered trimmer for the grasses (trying to replace it with a scythe but I haven't been able to sharpen it enough yet), and the machete for the more sturdy bushes. It would probably be easier and cheaper for me to pay someone to come and mow, but that would mean that I wouldn't be able to make some interesting discoveries: The past few weekends I have found two voluntary blackberry bushes and another that I had planted myself and thought to be dead but came back through the overgrowth. The other beautiful discovery was this:

I believe it's some kind of wild orchid, I've yet to identify it.

Anyone else would have just cut them with the mower and not notice. Further more, had I or someone else been mowing regularly probably none of these plants would have been able to survive or even germinate without the cover and protection from their weedy companions.

I also spotted a small blue and yellow lizard for the first time crawling through the mulch and rocks around one of the trees, which is very satisfying. I was beginning to wonder if predators would ever come to take hold of the habitat I meant to create.

That's the beauty of doing less, observing more, and letting nature do her thing.
7 years ago

Ken Peavey wrote:Used as an insulator, DE is close to fiberglass in effectiveness, however the weight would be an issue to consider in wall and ceiling structures.

I recently came back from doing some field visits to fired clay brick manufacturers, where I found that DE is being used as an insulator in kiln walls and ceilings with very good results. Its obviously raw mined unprocessed DE, not food grade, so it probably contains other minerals as well.

Here is a photo of the raw mineral:

I got this sample of a clay stabilized DE (or as it is called here: diatomite) brick:

It is a solid (no holes) brick and weighs about 1/3 of a standard solid fired clay brick of the same dimentions made by the same manufacturer. The manufacturer is highly empirical so he kept no record of the proportions of clay/DE used to make this one, but he claims that you could put an acetylene torch to one side of the brick while holding it with your hand and not get burned (he didn't mention for how long though ). This is by no means a real insulation test but you see what he was trying to get at.

One advantage of having the DE stabilized with clay is that it can act as a refractory/insulative material at the same time. The manufacturer also claims that he overhauled the vault ceiling on one of his batch kilns (pictured below) using this type of brick and it reduced the amount of coal needed for every batch burn by about 30%, which is quite a lot without making any adjustments to the combustion itself.

Another brick manufacturer is building a tunnel kiln (continuous operation as opposed to batch, pictured below) in which they are adding the raw DE as filler in between the refractory bricks and between the refractory bricks and ceramic fiber insulation in the ceiling of the kiln, which is expected to increase the insulation compared to just the layers of refractory brick and ceramic fiber.

This got me thinking that DE might be used for rocket mass heater cores. Particularly when making a cast riser where diatomite might be more easily available and/or cheaper than perlite or pumice, or when building the riser out of bricks if one can get hold of bricks like the one I have shown.

Some online sources cite a temperature resistance of up to 900 ºC, which I believe could be raised even higher using the right mix of DE/clay/other refractory minerals (like alumina), and thermal conductivity values from 0.06 W/mK for DE and 0.12 W/mK for Diatomite.

Should I move this post to the RMH forum?
7 years ago
Also google "layering" and "air layering". Fig branches root easily while still attached to the tree and in contact with moist soil.
8 years ago
More comfrey is sprouting, now there are 3 decent albeit small plants which give me hope for making more cuttings in the not so long term. We have finally had some consistent rains after a very harsh El Niño that has hit us for over a year, making last year very difficult and with very slow progress. Either the comfrey plants are enjoying the rain, or the weed fertilizer which I've been giving them from time to time (any chance I get, which is not very often, maybe once a month), or both.

Below is a picture of the concentrated weed fertilizer. When I first read about it others said that it would stink like hell, but I was surprised this time (it has been fermenting for about a month) because it smelled just like fresh cow manure, not really a stinky smell imo. I've been feeding this to my trees and plants, diluted in about 1:10 parts with water.
8 years ago