Looks like I am going to need about 600+ fence posts in the future.

I remember in the past driving across western Kansas where there is nothing but light rolling hills and plains. Here I noticed an unusual thing. Fence posts were cut from stone. It looked pretty cool. The thing is, stone would be very expensive.

The simple solution would be to go with steel T-posts. But we cannot have things simple . That would be too easy. After talking with my wife, a T-post steel fence is not what we really want. We would prefer something a bit more stout.

My original plan cooked up over the years was to build a fence out of "Drill stem." This is a byproduct of the petroleum drilling industry here in Texas. It is basically a low quality, thick wall steel pipe. The thing is, these days scrap metal prices have been through the roof. So this material is much harder to find.

So, I decided to research wood posts. These are expensive as well. Six foot, 4" diameter treated posts starting in the $8ea range going on up. These have an advertised lifespan of 25 years in the ground. So when you start adding up the prices of these, then factoring in that you may have to build the fence all over again in 25 years... made me think about alternatives.


The thing is, Concrete fence posts have been used here in the US. But they are not that common. But in the UK, Australia, and New Zealand they are much more common. Most of the information I found on the web is from these countries.

Here are some images I found. My favorite I think is the top one.









So here is what I was thinking:

What I would do is build fence posts molds. Most likely on 4x8' sheets of plywood, perhaps steel. On each of these I would be able to cast 6 to 10 concrete posts on each. The specific number of posts would be based on design. These mlds would allow a length of rebar to be suspended through it.

Then I would have a ready-mix truck come out where I could pour into multiple molds. Ideally I would have enough molds to pour 150+ posts each time.

Then after the posts have cured in the molds, take them out and place them. Then call to have the molds filled again.

Now this may seem like alot of work. It is. But the trade off in my opinion would be perhaps spending the same ammount as I would for a wood post fence, but having something which could last much longer.

In the part of the country you live in, little rain, no freezing, I bet they would work nicely.
How long are you going to make them?
How tall of a fence?

Pouring 150+ posts out of one truck is going to be quite a chore unless you have a team of people to help. That mud comes out of the truck pretty fast, and you're going to end up with a LOT of waste, as well as spending a lot of time cleaning up, tamping/vibrating the concrete into your forms, etc. I'd wager that the concrete will be starting to set in the mix truck before you're halfway done and the driver will end up dumping everything on the ground rather than get stuck with hardened concrete in his truck.

That's just my opinion, of course, and I could be wrong. You might be able to come up with a slick-ass system for channeling the mud out of the truck into your forms with no spillage, and keeping a steady rhythm between forms. But it would take some mega pre-planning and setup, as well as coordination with your helpers.

I would tend to think that these would be more easily done with your motorized mixer, using sackcrete. The last thing you want to do is risk paying for an entire truck full of Readymix and having it go to waste. That shit is too expensive for it. Plus, if you did it with your own mixer, you can control the process better. You could do a couple of forms per day and just rotate it out. Every evening, you pour 5 or 10 posts like clockwork. Next day, you strip the forms and do it again. You'd have it done in a few weeks.

All in all, though, concrete fence posts are a good idea. You'll just need to realize that they are not as maintenence-free as people think. But they will definitely last longer than wood or steel. Aesthetically they're not very pleasing, and your property will quickly gain a reputation as a "compound".

You will also have to have some kind of form release oil, and put something in them to attach the fence to.



Maybe some broken glass in the tops?

Sounds like a royal pain in the ass!

Not only do you have all the problems Tobus mentioned making them, but then you have to cart all those heavy things around and dig 600 post holes!

Ugh.

And how do you connect your fencing material to the concrete post?

I can cut wood posts for free, and we have a post hole auger on our tractor so wooden posts makes sense for me.
You can't cut wood for posts, and do you have a post hole auger anwway?

Sounds like your best be really is T posts. You can buy allot of posts for the 500 bucks you'd blow on a load of concrete, not to mention all the work and expense of the forms. Those forms could run ya another 500 bucks.

If you use T posts you can get the job done in a fraction of the time and sweat!
cast some heavy posts if you must and use them for corners and gates, and maybe near the house where you want to get fancy. But the whole plot?
Egad man, what are you thinking!! You'll have more labor and material in your fence then I do in my house!

I don't know how much free time you have. If your like me, there is never enough time to do everything I'd like to around the homestead.
Time is my biggest limiting factor, followed by money.
I know you have more money than I, and are probably stronger and younger, but still, sooner or later you might want to consider doing something the easy way?

Sigh....If you just gotta do concrete posts the way to form 'em up is to dig a long straight trench in firm earth, with a clear path to drive the truck along beside the trench.
Line the trench with plastic. Lay short lenths of rebar in the trench, and have lots of little scrap bits of plywood handy to shove in the wet cement to cut the pour into sections.
Then just pour it all at once with the truck driving along slowly by the trench.
Walk along compacting the pour as needed and inserting the wooden dividers.

You'll have a chore pryinh 'em up later, but not to bad.

I don't know about your area, but with a post auger and railroad ties you can probably get this done faster and cheaper. Even in our wet soil and hard freezing the ties last very well and can be replaced individually as needed as part of maintainence. I've only worked with concrete truck pours on sonitubes. Needed to fill about 45 for building supports at a scout camp. Absolute mess and I needed an extra truck load to make up for spillage. Very difficult to work with out of a truck unless it's a long pour even if you swivel the spillway. Short measured pours just weren't going to happen.

I was thinking just under 8ft in length. Perhaps a 4"x6" rectangle.

There is a good amount of rain in the location. It would maybe get to freezing temperatures once a year.




You are coming down to the whole core of the issue. This is a problem which I believe can be solved by creating the right infrastructure to facilitate mold pouring. Then having the labor on hand to pull it off.

See, the one building material we I can get in relative abundance is concrete. There is no shortage of that in North Texas. Hell... in Texas as a whole. With intelligent design it can be a low cost building material. One just needs to be prepared to handle the weight issues that comes along with it.

I was thinking of possibly building some pour tables. These would be (4) 4x6" 24' rectangular steel tubes elevated about 18" off the round. They would be used to make a frame table 4ft wide and 24ft long. I would build multiple tables. Plywood could then be placed on top and replaced as it wore out.

This would allow me to put a variety of frames and molds on the table. Two men could then work the table on either side to work the concrete in the molds. Starting on one end and working the concrete to the other end.

By creating this infrastructure, it could make large scale concrete fabrication alot easier. Sure I could mix up smaller batches with my current equipment. But utilizing a cement/concrete truck could increase volume... assuming I could figure out an efficient method to fill the forms.

The table system would make filling my angle iron/concrete building panels a breeze. The issue then becomes moving them.




You are right Bob. It would be alot of work. And would cost more than the T-post solution.

Postholes are the easy part. I can rent a two man unit for $60 a day. In fences I have constructed in the North Texas area on average can easily to 12-15 holes in an hour. Assuming of course the layout work has been done already.

There is somethng being missed however. In the move to a rural location, I am looking to create a viable manufacturing facility on the property. This is to pay the bills. So creation of the molds and applying some of these ideas could be enough to make a feasible business on the premises.

I guess this is where I kind of differ from your regular homesteader. My goal is to move to a rural area and set up a job shop. The primary focus being metals fabrication, however concrete and steel go together pretty well. So I would continue to do experiments and projects with this media. Mostly because I think that one day I will find a product application which will work. Some will call me crazy... but I have been called that before As in most of my life I have made my living by doing things which other people have said was impossible or there was no money in.

So on the surface, I would say your comments are dead on the money Bob. And you are right. The flip side from my view is that if approached in the right quantity and scale, these ideas are not so crazy.

The post holes probably wouldn't be as big of a problem as transporting them. You're right about that; them sumbitches will be HEAVY. At 150 pounds per cubic foot, a 4" x 4" x 6' post will weigh in right at 100 pounds. Trying to handle those will get old real quick.

You may be onto something, though. Maybe a hybrid system would truly be best. Concrete posts at the corners and maybe every 32' on center, with regular old T-posts at 8' centers between them. That would reduce the number of concrete posts needed while still providing rigidity to the fence. I just had to buy 40 T-posts for my current fencing project, and they're only about $2.75 a piece. They drive easily enough and do a good job. Especially if there are regular rigid posts in the fence.

Thed, you posted your reply while I was typing mine.

So here's the correction to my weight figure:

If your posts will be 4" x 6" x 8' long, they will weigh 200 pounds each. You ain't gonna be able to set those by hand. You'll have to figure out a way to pick them up off the truck and set them with machinery. And without cracking/breaking them in the process.

Lets say that the center piece of rebar was rolled into a loop at one end and welded shut. This end stuck out of the end of the concrete mold. Say just big enough for a chain hoist to be attached. Or, seeing that its under 250 pounds, I could just rig up a block and tackle with rope and do it by hand of a jib scafford mounted to the end of a pickup.

I was factoring the posts to be closer or around to 250 pounds.

My concern on this project would be the cracking. Thats I tend to think is sthe single issue which could wreck the project. The weight issues are not that much of a concern to me immediately. I know how I can handle those issues and have experience with building with heavy material.


Right now we are in the property financing stage of this project. Far away from doing any building. Before the fence phase even begins, there are other phases which would need to be completed. Specifically Earthworks and large scale planting (which I have started and will consist of over 2000 shrubs and bushes).

a shrubbery!!? !? !





For molds, would you want square or round?

For round I guess you could get several lengths of whatever OD pipe and split each length in half. Then weld tabs every so many inches on each half, drill holes through the tabs, then use bolts through the tabs to secure the two halves together. Once the concrete has set, unbolt the pipe halves and remove from the post.

If you set up a good number of these in a jig vertically, you could easily pour several tubes in one mix. Putting the molds next to each other would reduce the waste a bit, although keeping them secure would be an issue.

In essence, you would be taking a commonly-used cast-in-place concrete column model and scaling it down a bit.

But how do you keep the concrete from sticking to the mold, or becoming impossible to remove once set?

Also keep in mind round vs. square would save material (think $$ and weight) per post.

don't forget, you need a vibrator (not that kind you sickos) to get the concrete to settle properly, or you will end up with big pockets where it didn't settle. For getting the forms off, you need to oil them. I believe we used old motor oil and disel fuel... or was it kerosene... don't quote me, i just cant remember...

I would think square/rectangular would be easier to deal with. If using a round form, you'd have to pour it from the top, down the tube. Which means using a vibrator or other means to ensure you don't get any voids. With square forms, though, you can leave one face open and pour it flat on the ground, just using a trowel to smooth the open face. Virtually no risk of voids, and no vibration/compaction requirements.

I would just make sure to chamfer the corners of the forms.

You can use a release oil on the forms if you like, but I honestly don't think you'll have a problem on these tiny things without it. Just use good plywood like HDO or Betofilm or even Finnform. Something with a slick face or a good sealed surface will last you many pours. Just clean the surface well after each pour. Using form release oil is tricky because you can sure make your finish ugly if you put too much.

Yeah, for one day, then you'll go get a tractor with a post hole digger.
Make sure to ask the salesman if they have one with down pressure on the 3-point hitch, makes running the digger a lot easier.

You need a tractor anyway with that much land.
Maybe you should start a new thread for that.

Our little crawler doesn't have a three point on the back, so I hung a hydraulic auger off the front bucket. Works great!

Here is a crude sketch of the latest incarnation of what I was thinking.



Basically the mold is a 48x96" 14g sheet of sheet steel. It is then sheared (or laser cut) to yeild two endcaps per sheet. Plus three trapezoid shaped weld inserts. The sheet is then bent like the above corregated pattern about 7+ ft long. This would yeild trapezoid shaped posts when poured. The Weld inserts would taper the bottom end, hopefully increasing the ease in which the post was removed from the mold.

Notches are cut out of the endcaps which will hold in the concrete. These will be slots which can help suspend 3/8 to 1/2" diameter rebar. This rebar would be cut into 8' lengths. The end would be curled and welded shut to create a lifting eye. This lifting eye can be later used as a welding hardpoint for a steel crossbeam/pipe/rail on the fence after the posts are set.

I'd like to think I would then have 20+ of these forms cut and bent. I would just assemble and weld them together. This would give me 60+ post molds.

What I am thinking is that these could be set out. Then a glob poured on one end. Then the mass of concrete is pulled across the mold. After an hour or so, an edge rdius tool could be run on the outside trapezoid edges. Rounding them off some.

If additional hardpoints of contact are needed, they can be inserted after concrete has been poured and smoothed.



See here is the deal. There is nothing on the property. No fence or road. It is an overgrown field with some woods in the back. No water on the property. There are electric lines by the road.

Because of this, I have to figure out an order in improving the property. My largest concern is security... being able to store items, building materials, tools, and equipment on the site.

I have been considering getting a shipping container brought out. But quite frankly because the property is a big open field.. I am leaning against it. Plus the cheapest I found an 8x8x40 to be delivered on site was $1500. Thats a bit high for a beat up eyesore.

So until I have a location to secure larger equipment like a tractor or front end loader.. I need a place to store them first.

Interesting idea, Thed. You're essentially building pan forms, much like what we use at my company (we invented them, actually) for forming one-way pan/joist slabs. You're just forming the joists, with no topping slab.

The thing I see about your idea that's going to be a real bummer is bending the sheet metal to that shape, and then getting the posts out of the forms once they're cured. You can pull them out with the lifting eye at the top, but you'll risk cracking them if they're still "green". Which they will be for quite a while.

From your sketch, it looks like you're just going to have one row of rebar in these posts, down the centerline (the neutral axis), which won't provide any strength to the posts. Generally speaking, rebar is placed in concrete in order to strengthen it in tension. Concrete has excellent compressive strength but it has almost zero strength in tension. So for horizontal beams, for example, rebar will be heaviest at the bottom where the beam is in tension when it's loaded. The steel provides the tensile strength along the tension axis, while the concrete provides the compressive strength at the top in the compression axis. For a fence post that can be loaded in any direction, I'd think you'd want rebar near each of the corners for best strength development. Putting in one row of rebar at the centerline is not going to do anything except keep the post together while moving it. In service, it will provide no strength.

There's also the issue of having exposed metal on your fence posts. I would bet my next paycheck that the tops of your posts will be spalling the concrete off in 5 years as that exposed rebar starts to rust from the weather and the rust creeps down into the concrete. Just a couple of weeks ago, I sat through a lecture from one of the industry's leading concrete repair companies, where he explained that the number one leading cause of long-term problems was rebar starting to rust. When it does that, it expands and cracks the concrete around it, causing it to spall away.

If it were me, I'd build my forms from wood. It's a lot cheaper to build with, it is easier to change/modify, it can be disassembled if necessary for stripping, and it will give you plenty of pours. We routinely get 30+ pours on our plywood before it's too ratty to provide a decent finish. Steel will start to rust after the first few pours, even with a good form oil, and will start giving you a crappy finish and lots of rusty discoloration of your posts. It would be a piece of cake to build wood forms on a 4'x8' sheet of plywood with sloped sides for easy stripping.

And instead of angling the bottom of the post for easy stripping (which will make the posts impossible to set in the ground and stand by themselves), I'd just angle the sides and then make the endcaps of the forms easily removable.

As for the lifting point, I would really avoid having any rebar protruding from the top. I would cast in a sleeve near the top (using 1/2" PVC pipe or something). Your rebar could simply loop over the top of the sleeve and go back down the other side, providing plenty of lifting strength internally. To lift the post, you just slide a bar through the sleeve and use a lifting sling. This would keep any rebar from being exposed while giving you superior internal strength from the rebar placement. It would also give you a good anchorage point for future attachments to the post. The sleeve would be a pre-positioned bolt hole.

In fact, as I'm writing this, I'm thinking of a problem we've had at work lately. We have some heavy concrete weight blocks that we use as brace points for column and wall forms. We call them "dead men". They're just big square chunks of concrete with anchorage points on top. We fly them into place with the crane when there's no hard point to brace our column forms to. We built these about 7 years ago. And they were built with exposed steel protruding from the tops for lifting eyes. We are having to replace them all now because the concrete is cracking around the eyes from the steel rusting. So we're doing exactly what I just recommended. The new ones are being built with PVC sleeves so they can be lifted with slings or a forklift, and no steel is exposed.

I would seriously consider not having any exposed steel protruding from the concrete, or your posts will be crumbling apart in a few short years.

I'll keep that in consideration. Thanks... thats why we keep you on the payroll

The PVC idea is pretty slick. An inexpensive, easy to work material which would work pretty well. Perhaps it would be best just to use multple pvc tubes in each column/post for connection points.

The rust resistance of rebar sucks. Ill grant that without a doubt, as we had a similar problem with 1000 & 2000lb concrete blocks which we cast for testing the load capacity of bridge cranes we made. In hind sight the rebar lifting loops on them had seen better days. I could see how they would be a problem like you suggest.

One counterpoint however... what if tall exposed steel was painted to prevent corrosion?

I have numerous 2" thick concrete panels which are holding up great. The Angle iron edge on them are holding up fine. They have some rust, but are not damaging the concrete they are in. But the grade of steel used for these is much higher than rebar. Combined with a coating of millscale and they are still ok for being left outside to the elements. Its been six years now for someof them. Ill have to look closer to see if they are falling apart.

On a side note I have (4) 12"x48" pannels I was going to weld bolt-together flanges to make a firepit at the property. I am actually kind of excited about it, it should be neat to see how they hold up with temperature changes.


The last thing is about having a wedge shape on the post. This actually makes a square side column easier to set in a hole. Especially if you have planes which need to be aligned. The wedge point is dropped into to the hole, and digs into the dirt at the bottom. This acts as a hinge for plumming the post, where it keeps the post faces from coming out of alignment as you sink them.

That's what I was thinking if the intention was to have all those shapes formed in one sheet.
I don't see how it could be done. At least, I've never seen a press break die that would work for that application.
You'd run out of clearance in the break.
You'll need a fairly stout press to work 8' of 14 AWG. The "little" 60 tonner we have here wouldn't do it.
We have a nice old leaf break that would, and it's for sale if you want it!
Shipping on it would kill ya though -

It would be easy to bend up each mould separately, say with a one inch flange on the top.

While we're on the subject of corrosion of steel imbedded in concrete, I was wondering the other day if it is cool to imbed galvanized material in cement.
I was thinking of the galvanized fence panels and the little dome I'll be building this summer.

I cannot recall the exact link Bob. But I started looking into ferroconcrete/gunnite/shotcrete applications when you first posted on your dome cabin. In that reading, I remember multiple references that the best wire applications were uncoated.

This was the press brake I was considering using:



Its only a 3000 ton unit. Should be able to handle it

Aw.. just kidding. That press is from a autobody prototype shop I did work for in the past outside of Detroit. Its not there anymore. That big press sprouted a massive hydraulic leak and started a fire. The whole shop burnt to the ground.

But on that note... the access to job shops and heavy equipment is my "ace in the hole" for the whole rural property venture. If the 1" flat sections between the trapezoid molds were switched to a 1" round radius (making one wide arc radius bend instead of two... this part could be stamped on a press without too much difficulty.

The wood however makes sense for the molds.


The funny thing I am coming to here. It really seems that the most cost effective solution to the property barrier is a ditch berm with thick bushes and trees. I have been running numbers on these projects. The ditch and plants is the cheapest and IMO the most aesthetically pleasing option.... in 3-5 years after doing it.

Then if needed, perhaps take up Bob's suggestion and just fence off smaller sections within the property.

Well, I sorta figured this is what you were aiming at when you wrote -

Sounded like you wanted a tall fence around a small area so you could use it to store gear and such.
Tall concrete posts and lots of barbed wire would certainly add a certain "Stalag 13" air to the place.
Add some signs like these and most folk would stay out!


Oh, and that's a bloody huge press!

This is very common in the concrete construction industry. It's what we use for parking garages, where they have multiple barrier cables going up the sides of ramps or even at the perimeter. When we set our column forms, we just install PVC pipe for sleeves through the columns. After the columns are poured and stripped, they can just come back through and run their barrier cables through those sleeves. That would be perfect for a fence application as well, if you were going to just use high-tension wire.

And your pick point sleeve would act as a perfect place to loop your rebar over. You could just put two pieces of rebar in each post you're pouring. Each piece would start at the bottom and loop over the sleeve at the top and come back down the other side.


Paint doesn't prevent corrosion. It just delays it. If you rely on paint to protect your exposed rebar on a fence, you'll be out there every couple of years, repainting the tops of your fence. That sounds like a royal pain in the ass to me. I'd rather just spend the extra time and effort up front so I didn't have to spend so much time later maintaining it.


Exposed metal on the outside isn't the problem. It's rebar that goes inside the concrete that causes the issue. As I recall the way your panels were constructed, the angle iron can rust away without causing spalling. It's the grid of steel inside that would be the issue. But I think those panels would probably be fine for a long time, since the steel inside the concrete would take quite a while to rust out.

The issue I see is that with a piece of rebar coming out the top of a post, it is exposed to weather. Even if you paint it, you won't be able to reach down into the first few millimeters where it's inside the concrete, and that's where the rust will begin. It will eventually travel down the length of the rebar inside the concrete, causing expansion and spalling.

Even rebar that is totally inside concrete can eventually rust out, causing the same problem. This is why structural engineers require a minimum amount of "cover" for rebar. You can see examples here: http://www.swconcreterepairs.co.uk/defects.htm That's what happens when you don't have sufficient cover for the rebar, or for any reason the rebar starts to rust inside the concrete.

They spray zinc on the bottom of bridges to protect the concrete. Looks like it would be ridiculously expensive.
http://www.corrosionsource.com/events/inte...cts/bullard.htm

4" or 3" concrete posts molded with PVC tubing

I need to renew several hundred trail rails and posts and am thinking of using PVC tubes, cut in half, then wired closed, stood upright and filled with concrete along with a 3/8" rebar.

Labor cost is relatively inconsequential, because I reside in southern Mexico. Material cost, though is very high.

Does anyone have any experience doing this, or advise on whether I should proceed with this?

Welcome, catemaco -- glad to have someone with us from the land southward. I don't believe we've yet attempted to do this, but your idea seems sound. It's the same basic principle Theduardo was planning for fence posts. I think it would actually work very well. Do you plan on making the posts and them hauling the finished posts to the site, or do you plan on making the posts onsite?

I imagine you'd know best the logistics involved, and with relatively inexpensive (and GOOD) labor available to you, you may have the freedom to do it either way.

First of all... Welcome to the Forum!


I think your PVC mold method could work. The big issue I think you will have is getting an even and uniform compaction of concrete in the form. Somehow you will probably end up having to vibrate the molds during pouring to make sure it fills evenly.

Fortunately we have an Engineer on the Freesteader payroll who can help you out with your concrete issues

Vibrating the concrete in the form should be easy. I would make it a runny mix (i.e. slump less than 3") and fill the form in short lifts (say, no more than 12" at a time), then move the rebar up and down rapidly. It will liquefy the concrete in the bottom of the form. You can also tap on the sides of the form to help vibrate around the edges. Once you've put in one lift and vibrated it, repeat as necessary until it's full.

If I were doing this, I would probably not use wire to close the two halves of the PVC pipe. This would be awkward to close up and strip. I'd use big hose clamps. It will ensure good alignment of the halves and make it much easier to set and strip. They can be slid from the top down and then tightened with a screwdriver or ratchet. And they'll keep their circular shape pretty well.

Keeping the form plumb during the concrete placing operation will likely be the most difficult aspect of it. You'll probably want to attach braces to one side of the form, but in such a manner as not to impede the installation/removal of the clamps.

Be sure to oil the insides of the forms between uses, and it will last much longer! Plus it will be easier to strip and give a better finish. It'll clean off easier too. I just use a thick 3-in-1 generic oil. Some people recommend WD-40, but I think it's too thin (runny) for the job. Plus, it's a water displacer, so it's not very well suited for placing a water-based mix.

thanks, that was a thoughtful reply.

Considering my Mexican labor cost, and probably Chinese hose clamp cost, I think I will stick to rusty old wire.

Keeping the form plumb is not a priority. These will be railing posts in a very rustic setting.

For that matter, I have access to relatively brown river sand and gravel, and I plan to add cement color to make brown posts.

As for vibrating. I usually read to NOT vibrate the form externally. But in the past I have done so with sonotube products and never had a problem.

Actually I would love a 3 1/2 inch or 4 inch sonotube (These are cardboard tubes stiff enough to form columns up to 24", but unfortunatley are only available above 4 inches).

I do not plan to oil the PVC forms, I previously tried that on sonotube forms but afterwards had a heck of a time to get the finish to stick. Anyway, these forms are so mickey mouse, I could probably release them with a baby spoon, ar a smack of a sledge hammer.

I´m still maybe a month away from forming my first post.

Meanwhile though. I have a lot of bamboo, that I originally thought of using for railings. But WOW, after reading the bamboo literature I give up. In my experience fresh bamboo lasts for less than a year, and to make it last longer seems to be equvalent to stainless steel.

Instead, I am now mulling totally environment unfriendly 1 1/2 inch black PVC tubes as handrails. At least they seem to last forever and are nice and round. Gee do they come in brown?

Where have you read that?

Here in the United States, external form vibrators are all the rage in the concrete industry. On large commercial jobs where vibration of the concrete is typically done with internal vibrators, there are almost always finish issues (voids). Especially at the bottoms of the forms. A lot of companies are going to external vibrators that clamp onto the wall forms or column forms. In fact, the company I work for is looking into it as well. It tends to be a better option than internal vibration, from a quality standpoint, because there is less risk of over-vibrating the mix and forcing the large aggregates to the bottom.

you could just dig the hole, stick a 4 or 6 inch pvc pipe in the ground and fill that up with concrete.

8"x8' pvc cut in half, sprayed with light oil, rebar is caged inside of pipe to keep centered. Poured in place and then pvc shell removed. The rebar can be used for welding something on or just capped over with cement. A friend of mine put used bowling balls on top of his. I will use it for welding my trusses of the greenhouse when I get to that stage. If you thin mix and slow pour you will not need a vibrator. Scrap pvc is available from pipe places that put in water and cable. They let me have mine just to get rid of it. Anything under 20' to them is mostly scrap.