jgray152

I have been engineering a "system" on how to do this efficiently. I needed to build a form system that was able to be reused many many times without screw holes stripping out, without boards breaking or needing to be pried loose with a claw hammer. I needed the forms to be able to be taken off piece by piece very easily and I had to make the form stand on its own without falling over. I also needed the form to have an option to have a mailbox rock shelf.

On top of that, the inside of the form needs to have some sort of rock texture.

So here is what I came up with after a week or so of drawing. These pictures are of work in progress and I will be updating this thread as I go along. Nov 2nd is when I should be able to pour the post.

Drawings of Posts


The starting of the form design. Internal dimensions are 8"x8"x72" The "gap" is where a 3.5" thick rock shelf will be. I have to pick up more hardware to finished putting that part together.

jgray152

I used 4 eye bolts at the top to secure a latch to which the rope is tied too.

I bought 36" angle iron and cut 4 stakes, welded 2 large washers to each stake for the rope to pass through. The stakes are cut to a point at their bottom. I wanted something very strong that I could hammer into tough rocky soil like my driveway.

I have 2 1" Stainless steel o-rings tied about 2/3 of the way down on the rope before the rope enters the stake. These SS O-rings are used to cinch down the rope easily when making adjustments to straighten the post form.

TO hold the boards together, I drilled 7 holes on each board. I then inserted some screw in nut sleeves into the boards which fit in between. I then use bolts which fit through the outer boards and thread into the nut sleeves.

I may weld washers to the tops of the bolts so I don't need tools to put them in.

More to come...

genecarp

Good thread, cant wait for the pour-----no, cant wait for the strip. GMOD

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Cole82

Did you cut the rock shapes into the form? or are the rocks mortared on.

jgray152

The rocks will be "carved" with a grinder after the concrete cures. The rock design is veneer so it needs to be as straight as possible.

I will be using shower pan liner to make cliff indentations like you see in flag stone. THe liner is very smooth so I am gong to be looking for some durable spray on bed liners in a can that will add texture to the show pan liner. I will be adding primer to the liner first. Just before the concrete is poured, I will be adding release agent, probably mineral spirits (which works great) to the inside of the forms.

I forgot to mention that I will be modifying the top of the form so that a 2" thick square cap is created. I will be making the cap look like granite.

I will have a lamp on top of the post using 2.5" electrical conduit for the lamp to be secured to since the 2.5" ID conduit has an OD close to 3" which is what I need for the lamps. I will then have 1" conduit go straight down the post and exit out of the 2' footer underground.

I will add wire mesh reinforcement inside. Either that or 3/8" rebar.

No real stone here

jgray152

Here is a couple more images.

O-Rings used to cinch the rope. Works VERY good. Just a little tough to loosen but still very easy.


Shower pan liner used to create flagstone textures. Image is the unfinished removable mailbox rock shelf form. Rigid foam also used, broken and roughed up in areas.

lukachuki

Same

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Tim

Build a man a fire and he'll be warm for the night. Set a man on fire and he'll be warm for the rest of his life. - Terry Prachett

Tscarborough

Strap clamps work well for that type of forming and are easy to work with.

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oldfrt

There is an old timer here who has built a form for Ornamental concrete lamp posts.Makes apretty good living by selling to developments and condo units that want something different for street lights.He's incorporated the wire chase and access panel into his forms.A couple hours polishing and paint bring him about $400/ea.

Not a bad little gig for a retired Contractor.
I'm pretty sure he had some kind of hard plastic liner manufactured to line his form , for durability.
Pretty interesting to see the progress as he gets these units laid out and finished.

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genecarp

Has he posted them here? if so do you remember where? GMOD

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jgray152

Didn't think of those. I'll look into them. Thanks.

I wouldn't mind speaking with him

Plastic liners, form liners would make easy work of this. I won't be polishing or painting but I will be staining.

The rigid foam is disposable in the mailbox form picture above. I pretty sure the foam will not come out whole.

There are far more ways of doing what I am doing. After all I am still in my infancy stages compared to other contractors.

Pricing on mine, for a lamp post with mailbox rock shelf, installed I am thinking about $900 including a basic post lamp and possibly a mailbox but that may change. This is being done at a friends house, so his property is the rat in testing

Just to form one, carve and color with lamp and mailbox would probably be around $750. Without lamp and mailbox maybe $650

Why so high you ask? There are many benefits with concrete posts compared verses granite post, real rock post, fiberglass posts, cultured stone (lick n stick) post etc.. There are some cons as well but I feel the pros push far ahead of the cons. If a customer feels something is worth the money compared to another product, they will buy it.

TimelessQuality

Cool concept... should be able sell a few of those

Just a couple of observations..
Footers- You probably are planning to use them... just make sure they are sized appropriately, and tied to the pour. There will be a lot of weight, and top heavy too.

Form Boards- Looks like 2x material. Would be good for a couple pours, but may begin to split as they dry out. Plywood would be more stable in the long run..


Cant wait to see how it comes out

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jgray152

Thanks! I hope I do!
I will be digging a 2' footer and will mushroom the bottom of the footer for a larger foot print. I am thinking this should do?

I will pour the footer first, then while the footer is still wet put the form over the footer, insert rebar from the top into the foot as well. Conduit will already be in place for the lamp. Then I will pour the form and mix it in with the footer so its all one piece.

I may have to enlarge the bottom foot print on the form so that it will sit on the ground around the footer and not in the concrete of the footer.

I am sure there will be some more engineering changes as I go along with this.

I was thinking of plywood as well. I would need 3/4" plywood but I was worried if I used the threaded nut sleeves in the ends of the plywood that the plywood may split, but maybe not. In fact I have some extra 3/4" plywood I will test out to see how it works.

I was not thinking of the wood splitting when purchasing materials but after I cut the wood I noticed some large splits in the wood gaping to almost 1/8" which I was not happy about.
Same here!

scrapecc

Its too bad you couldn't build the main box out of metal, maybe with piano hinges on the outside so it would just open up as it were stripped. plus with the right liner it would last forever! Just a thought. I have been kicking around the idea of something similar for retaining walls, A clip on concrete cover for the I beams that hold the precast panels in place.

jgray152

I was also thinking of something similar to your idea. I am on a budget right now since business is slow. Eventually I might be able to find some metal or something like a hard urethane or something else. It has to be light and if I went with metal it would be heavy i am sure. If I went with thin metal (Aluminum) I would need metal bracing.

I do fabrication with steel as I have a welder and some proper tools but no for aluminum.

Money is the issue right now.

DeckMan77

Dealing in the fence industry this could be a great upsell to future customers. Love to see pictures from multiple stages of the concrete pour and finish. Great idea you came up with here!!

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scrapecc

I think you could get away with 10 gauge steel, braced with simple angle iron. That wouldn't be much heavier than the wood. If you look at forms for concrete retaining wall blocks. Pictures of those forms may inspire you a bit also. Urethane is quite expensive, but if you find a cheap source for it please let me know! I am working on an idea right now for precast stoops you can bolt together.

jgray152

Please keep me informed of your progress with your idea. I am sure both of us could learn from each other

In fact, I could get thin flat steel and weld it to the 10 gauge plate sticking out about 1". I could bend this flat steel to shapes of the stones and there would be me mold. No grinding Just, heavy. possibly.

The great thing about this is you can take ANY old fence post and create a form similar to mine, install the form around the old wooden post, maybe dig down about 1' or so around the old fence post and pour concrete in the form going over the old fence post. You could even just remove them but this might be easier.

TimelessQuality

sheet aluminum?

If your prototype works, just add a layer of 1/2 ply to the outside, and go to town

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oldfrt

Sorry Gene,
I meant locally.
I will try and get pics though.
If it rains as predicted tomorrow,I'll stop by his shop and see if he's there.

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There is no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.Information gathered here may be for the sole purpose of entertainment.