Author Topic: Concrete dragonfruit post  (Read 5377 times)

spaugh

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Concrete dragonfruit post
« on: January 13, 2020, 12:09:28 AM »
Just made a form this weekend and poured one.  I will update the thread in a week or 2 when I get the form done for the top supports. 

The form is made of plywood and 4x6 lumbers.  Trimmed down slightly to make 5x5 post and a smaller spot on top to set a support onto.  Motor oil was brushed inside the form to keep the concrete from sticking.  I already have a harbor freight cement mixer for doing small jobs here.  Makes a few hundred pounds of mix super easy. 

We use crushed recycled concrete 20$ per ton.  Mixed 5:1 with portland cement.  9$ for 95lbs of portland.  Can make posts for around 3$ a piece.  Using old 1" well pipes I had laying around for structural support.  They are stronger than rebar and galvanized. 

These are going to be very cheap to make and will last a very long time. 

























Brad Spaugh

SeaWalnut

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Re: Concrete dragonfruit post
« Reply #1 on: January 13, 2020, 12:20:10 AM »
Nice work! Let them cure well .I think after a month they will get stronger.
Somme years ago when i worked in constructions i was making electric poles and centrifuged concrete poles( hollow in the middle) and modular bridges and buildings  like the building that houses the biggest laser in the world.
For rebar we used tensioned steel ropes.
I still think rebar is better than the pipe but these will last since they are just poles and its a lot less labour than to bend and cut and tie rebar to fit such small space.
Vibrate the concrete well to avoid air gaps and let it cure well before handling to avoid something like this  ;D .
« Last Edit: January 13, 2020, 12:30:06 AM by SeaWalnut »

Forester

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Re: Concrete dragonfruit post
« Reply #2 on: January 13, 2020, 03:21:09 AM »
It looks reliable, but why not pick up a 4-inch plastic tube, fill it with your mixture and it will be more reliable.
❀ Sergey ❀

Ulfr

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Re: Concrete dragonfruit post
« Reply #3 on: January 13, 2020, 04:57:01 AM »
Looks good :) I used scrap pipe in some of mine too.

pineislander

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Re: Concrete dragonfruit post
« Reply #4 on: January 13, 2020, 07:54:03 AM »
If you have a good flat concrete slab you can eliminate the plywood bottom and just pour on a sheet of plastic. Cut the plastic oversize and wrap around post after pouring to keep it moist, even submerged in water is OK. Concrete cures far stronger the longer it can receive water, 50% stronger if kept moist for 7 days.
.

brian

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Re: Concrete dragonfruit post
« Reply #5 on: January 13, 2020, 11:03:52 AM »
Nice! DIY concrete work is so satisfying, and you even got the whole family in on it.

What is your intention for these?  Vertical posts to tie dragonfruit cactus to?  Do they need much more support than wood or steel posts can provide?

Kevin Jones

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Re: Concrete dragonfruit post
« Reply #6 on: January 13, 2020, 11:12:15 AM »
Nice project... well executed too!
I agree with Pineislander... After the concrete sets... keep your posts wet for a few weeks to help them cure with maximum hardness/strength.
It may seem counterintuitive... but it really helps your concrete to hose them down regularly.
The slow wet cure is the best cure!

Kevin



« Last Edit: January 13, 2020, 11:15:47 AM by Kevin Jones »

spaugh

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Re: Concrete dragonfruit post
« Reply #7 on: January 13, 2020, 11:34:59 AM »
The weather is good now for concrete curing.  They will go in a shady spot and covered with a tarp and periodically wetted.  Won't be using them until May.

Brian the plan is to make a bunch of these to put out in a new orchard here.  I'm fencing more land to farm on and want these to last forever.  I will put in 2 rows of DF to use a fire buffer on the north and east sides of the orchard.  That's where the fire comes from and our property backs up to wilderness reserve that's all overgrown.  These will give my avocados some space in case of wildfire.  I put the stuff I care less about in areas more likely to burn. 


Wood and steel are strong enough to support a big plant but the wood rots and steel rusts at the ground.  Even galvanized posts wont last forever.  Recycled concrete is cheaper, stronger, and longer lasting.  And provides better grip for DF roots.  If you look at DF farms overseas in India and SE Asia they all use concrete.  So that's what I'm doing.  I've already got 5 wood posts and 10 steel ones but eventually those will tip over.  So when you want to do a big planting and keep it functioning long term concrete is it. 

These are similar to what I'm going for.  My top supports will be square and rebar reinforced. 



« Last Edit: January 13, 2020, 11:38:47 AM by spaugh »
Brad Spaugh

ricshaw

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Re: Concrete dragonfruit post
« Reply #8 on: January 13, 2020, 12:26:04 PM »
I like to add a 1/2" threaded anchor bolt to the top of my concrete posts.



Vernmented

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Re: Concrete dragonfruit post
« Reply #9 on: January 13, 2020, 01:32:18 PM »
Wonderful! I have been dying to make concrete posts for quite a while now. It is my understanding that you don't really need the toppers. The DF will umbrella just fine on it's own. Looking forward to this thread.
-Josh

shaneatwell

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Re: Concrete dragonfruit post
« Reply #10 on: January 13, 2020, 01:33:32 PM »
Very cool Brad. what did the delivery cost on the crushed concrete?
Shane

spaugh

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Re: Concrete dragonfruit post
« Reply #11 on: January 13, 2020, 01:54:28 PM »
My neighbor brought it over for free.  He has a big dump truck and gets big loads of it down off hwy 67 not far from here.  The place is called Enniss Inc. off slaughterhouse canyon in lakeside.  You can take your pickup there and they will scoop it into your truck with a bucket loader if you want to pick it up.  They have a drive on scale that weighs your vehicle before and after.  Theres all kinds of materials you can get over ther if you ever need cheap materials.  They have sand, dirt, aggregates, recycle concrete etc. 
Brad Spaugh

Ulfr

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Re: Concrete dragonfruit post
« Reply #12 on: January 13, 2020, 04:11:26 PM »
Wonderful! I have been dying to make concrete posts for quite a while now. It is my understanding that you don't really need the toppers. The DF will umbrella just fine on it's own. Looking forward to this thread.

I thought the same and didn’t make tops. Some cultivars hold on really strongly and so it may indeed be the case but I had some that threw no aerial roots at all. I would have had to tie them on in some permenant way. I ended up making tops.






simon_grow

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Re: Concrete dragonfruit post
« Reply #13 on: January 13, 2020, 05:53:19 PM »
Brad, those are looking awesome, they should last a long time. Dragonfruit are are so easy to grow, delicious to eat and beautiful when the flowers are in bloom and when the fruit is cut up on a plate.

Simon

pineislander

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Re: Concrete dragonfruit post
« Reply #14 on: January 13, 2020, 05:54:04 PM »
Wonderful! I have been dying to make concrete posts for quite a while now. It is my understanding that you don't really need the toppers. The DF will umbrella just fine on it's own. Looking forward to this thread.
I'm sure it will spread out but it may break off at the top  especially in a strong storm. They climb and attach but somewhere around the top of the post the single branch divides into multiple branches which becomes very heavy. I've never seen anyone try nothing on top but good luck with it. The closest I've seen is growing up trees but they follow branches

SF

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Re: Concrete dragonfruit post
« Reply #15 on: January 14, 2020, 11:48:32 PM »
Brad, the concrete posts look wonderful. I thought your current setup was amazing, and now you have an improved version! Can't wait to see the full setup, filled with dragon fruits.


roblack

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Re: Concrete dragonfruit post
« Reply #16 on: January 16, 2020, 08:20:12 PM »
Impressive! Really like what you are doing with the orchard/farm/oasis.

spaugh

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Re: Concrete dragonfruit post
« Reply #17 on: February 25, 2020, 12:36:07 AM »
I made a bunch of posts with these top features but Ive decided to just go topless with them.  My friend Thy sent some videos of vietnamese techniques and convinced me its not necessary to have tops.  So the rest of the posts won't have any top feature going forward.  Much easier, cheaper overall Im happy with that.


Brad Spaugh

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Re: Concrete dragonfruit post
« Reply #18 on: February 25, 2020, 12:39:41 AM »
I made a bunch of posts with these top features but Ive decided to just go topless with them.  My friend Thy sent some videos of vietnamese techniques and convinced me its not necessary to have tops.  So the rest of the posts won't have any top feature going forward.  Much easier, cheaper overall Im happy with that.



You had me doubting myself. I started trying to think of good ways to make toppers. hahaha. Those posts look amazing. I want to make these so bad.
-Josh

spaugh

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Re: Concrete dragonfruit post
« Reply #19 on: February 25, 2020, 12:45:22 AM »
This is the top from India that I was going to copy.  I can still make it if I decide to but they will be a pain.  I would use a miter saw with 10" metal wheel to chop rebars up and use a jig to make squares and cross pieces.  Weld that all up for each top.  And make a pain in the ass mold for the whole thing.  Its doable but the way they do it in vietnam, looks to be totally un necessary.  I will dig up the video and post it here. 

Brad Spaugh

spaugh

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Re: Concrete dragonfruit post
« Reply #20 on: February 25, 2020, 12:53:42 AM »
My neighbor dropped off 4 more tons of crushed concrete so we have been using it for small jobs.  Heres a 4x8' pad we made.  A propane tank will be set there to power a backup generator in case of fire or fire related brown outs.  That will run the irrigation pump if the grid goes down.

« Last Edit: February 25, 2020, 12:56:20 AM by spaugh »
Brad Spaugh

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Re: Concrete dragonfruit post
« Reply #21 on: February 25, 2020, 01:05:59 AM »
My neighbor dropped off 4 more tons of crushed concrete so we have been using it for small jobs.  Heres a 4x8' pad we made.  A propane tank will be set there to power a backup generator in case of fire or fire related brown outs.  That will run the irrigation pump if the grid goes down.



Beautiful! I have that same mixer. I use it to make my potting mix. Is that ginormous water cistern?
-Josh

spaugh

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Re: Concrete dragonfruit post
« Reply #22 on: February 25, 2020, 01:13:20 AM »
Its a water tank in case of fire. Every house in the area has to have a 10,000 gallon tank for the fire dept to pump from if necessary.  We use it to irrigate with also.  It has a float switch on it and it stays topped off. 
« Last Edit: February 25, 2020, 01:15:01 AM by spaugh »
Brad Spaugh

Kevin Jones

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Re: Concrete dragonfruit post
« Reply #23 on: February 25, 2020, 09:50:42 AM »
What's your source for water to fill that monster?

Kevin

spaugh

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Re: Concrete dragonfruit post
« Reply #24 on: February 25, 2020, 10:09:00 AM »
We are on well water Kevin, theres no city water available here.
Brad Spaugh