casting concrete posts

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casting concrete posts

Postby cooked » Tue Jun 24, 2014 11:50 am

Being in a state of financial embarrassment at the moment (this will pass) but being the proud owner of a heap of sand and three sacks of cement that are slowly hardening, I am thinking of casting concrete fence posts, 250cm. 4 bits of rebar, 3hun? I have a vibrator and imagine making custom posts with ring screws in the right places, rounded corners etc. Does anyone have experience doing this? I didn't have much joy on Google.
This leads me on to another question: concrete post here always have feet, is this, as I suspect, because the concrete is generally too wet? I used to concrete galvanised metal posts in back home and they never moved.
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Re: casting concrete posts

Postby Mike Judd » Wed Jun 25, 2014 7:05 am

Not a problem casting posts yourself and you couldn't possibly make them any weaker than the Thai one. The thin wire that they use as reinforcing is a joke to start with, that's why they break so easily as they can't take any tension. If you use deformed steel it's best ,other wise bend the ends over if it's the plain steel. Plus use small stone not the 20m.m. large stuff and a stronger mix, 3--2-- 1 The foot that they put on their ones is because they don't always concrete them into the ground.
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Re: casting concrete posts

Postby Roger Ramjet » Wed Jun 25, 2014 7:24 am

This might help: http://www.buildeazy.com/house_property ... page1.html just make sure you have plenty of plywood, or if you are rich, steel. With the plywood brace it, brace it and brace it. You can get "furry" planks from any wood yard, they are also very cheap, but can only be used once or twice. To stop the post from "sticking" in the ground use plastic or a three sided hole (with the forth side being the cheap mean and nasty plank, that way when they have set all you do is remove the plank and lower them to the ground. The more bracing used the better.
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Re: casting concrete posts

Postby cooked » Wed Jun 25, 2014 8:20 am

Mike Judd wrote:Not a problem casting posts yourself and you couldn't possibly make them any weaker than the Thai one. The thin wire that they use as reinforcing is a joke to start with, that's why they break so easily as they can't take any tension. If you use deformed steel it's best ,other wise bend the ends over if it's the plain steel. Plus use small stone not the 20m.m. large stuff and a stronger mix, 3--2-- 1 The foot that they put on their ones is because they don't always concrete them into the ground.


Thanks, that's what I thought concerning stone size but I wasn't sure. I have driven all over and have not been able to find smaller stones. I think that I have seen premixed concrete however, in sacks. so maybe this is the solution. Meaning that my cement will continue to harden.
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Re: casting concrete posts

Postby cooked » Wed Jun 25, 2014 8:22 am

Roger Ramjet wrote:This might help: http://www.buildeazy.com/house_property ... page1.html just make sure you have plenty of plywood, or if you are rich, steel. With the plywood brace it, brace it and brace it. You can get "furry" planks from any wood yard, they are also very cheap, but can only be used once or twice. To stop the post from "sticking" in the ground use plastic or a three sided hole (with the forth side being the cheap mean and nasty plank, that way when they have set all you do is remove the plank and lower them to the ground. The more bracing used the better.


Thanks, I plan on casting my fence posts on a work bench. I will try using motor oil to stop sticking. I did all sorts of concrete jobs in the past but I never did anythung precast.
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Re: casting concrete posts

Postby Mike Judd » Wed Jun 25, 2014 9:23 am

Re small stones etc; I found the sand what they use when making their blocks is good, it's dark grey but helps give you the perfect mix for strong concrete which consists of various sizes of material ,large stone down to sand and then cement binding it all together. They don't seem to have what we call river sand (Course) available , which we use for concrete in the West.
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Re: casting concrete posts

Postby cooked » Mon Jun 30, 2014 4:16 pm

Well I planted my first post today, it doesn't look as nice as I should have liked but it seems solid enough. I started with a 14 x 14cm post 220cm long (100Kg), did all sorts of things to get it into it's hole and it didn't fall apart. I used the larger aggregate available and a 3 hun plain steel rod, bent at the ends, thanks for that tip. I am now awaiting for complaints from the neighbour as his newly planted wooden posts (the reason that I started this affair) were well into our land, I still left him 5 cm. I think I'll start a production line for myself, I was much encouraged by my first try.
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Re: casting concrete posts

Postby MGV12 » Mon Jun 30, 2014 5:40 pm

cooked wrote:Well I planted my first post today, it doesn't look as nice as I should have liked but it seems solid enough. I started with a 14 x 14cm post 220cm long (100Kg), did all sorts of things to get it into it's hole and it didn't fall apart. I used the larger aggregate available and a 3 hun plain steel rod, bent at the ends, thanks for that tip. I am now awaiting for complaints from the neighbour as his newly planted wooden posts (the reason that I started this affair) were well into our land, I still left him 5 cm. I think I'll start a production line for myself, I was much encouraged by my first try.


You never know until you try ... if someone who spends most of their life tending to rice can do it why not you?

Mind you ... a picture might be more convincing!

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Re: casting concrete posts

Postby cooked » Mon Jun 30, 2014 6:03 pm

Yes, coming up! The other good news is that there is another chanote that nobody bothered to tell me about so I have to do the whole surveying again. Good news, because I was still able to move the post this evening. Also good news because unless I had done this the neighbours would have taken 15 cm of our land, which is important on that side.
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Re: casting concrete posts

Postby sirineou » Sat Jul 05, 2014 1:27 am

consider the following method
make a long form as if you were building a foundation beam but make it the desired size of the post, , probably 6"x 6"
every so often,, depending how high you want the posts , place a stop , made of a piece of Styrofoam insulation,
From the top spreaders that you use to keep the open top of the form the desired width, (probably 6")
hang your rebar with a piece of tie-wire
pour your concrete as if you were pouring a beam, making sure to vibrate it, if you don't have vibrator use any power tool you have would produce vibration if used improperly, I use a palm sander. If you dont have anything that will vibrate tap the form with your hammer.
when concrete dries , remove the two sides of the forms, the Styrofoam stops will separate the beam in to equal size posts
Depending on the length of your beam form, you can produce many posts that way.
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Re: casting concrete posts

Postby sirineou » Sat Jul 05, 2014 1:28 am

An Idea so good it was worth posting twice :lol: , please remove double post
consider the following method
make a long form as if you were building a foundation beam but make it the desired size of the post, , probably 6"x 6"
every so often,, depending how high you want the posts , place a stop , made of a piece of Styrofoam insulation,
From the top spreaders that you use to keep the open top of the form the desired width, (probably 6")
hang your rebar with a piece of tie-wire
pour your concrete as if you were pouring a beam, making sure to vibrate it, if you don't have vibrator use any power tool you have would produce vibration if used improperly, I use a palm sander. If you dont have anything that will vibrate tap the form with your hammer.
when concrete dries , remove the two sides of the forms, the Styrofoam stops will separate the beam in to equal size posts
Depending on the length of your beam form, you can produce many posts that way.
I talk to my self because I am the only one who will listen
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