Ah.. may I ask why the need to create your own concrete blocks?

I never used milk cartons but I think you have to make sure that it stays squared especially when the top/lid is cut.
Some times ago, I made 1'x1' concrete tiles using pre mix. I built the mould using 2x4's and used plastic so concrete wont stick to the wood. You can get textures if you use vinyle, mix peat moss, add broken pottry etc.

ianna, the need is cost and color, LOL I figure it would be a lot cheaper to make my own and I can add the color I want to the mix.

chowdhry, I have squares of tile that I plan to wrap with plastic to set in the spout end of the carton. I could make them with hypertufa but I want them to be heavy and strong.

I have a heavy plastic tray that I can fit the cartons in to keep them straight.

I guess it won't hurt to give the milk cartons a try since the pre mix is not that expensive.

If this is milksized, then you are planning to make something along the lines of bricks right? Have you checked out Lee Valley Tools for the molds? I'm figuring that it might simply be cheaper in the long run to get the right mold rather than risk uneveness of milk cartons. Or you can purchase the mold from art stores like Michaels.

You use a spray to grease the molds to help release the concrete stuff.Also the reason concrete blocks have holes is because it reduces the weight and also it allows you to pour cement & rebars into the holes when stacking them up to build walls.

I had to ask - I used to work for a company that produced pre-stressed, concrete poles for telephones and I'm aware the process is far more involved in order to create a strong pole with properly distributed concrete and it's sedimments. So basically this is a very involved process. I would especially not recommend using anything home made for building elevated structures for example.

I want to make brick size pieces to use as a border in a flower bed. I wanted to make my own so I could color the cement. I want to use two colors, light pink and light green and stagger them like lattice.

I remember seeing something like that while I was visiting my sister in Oregon and always wanted to make the same thing:-)

well here's a Canadian source for garden molds, look for the edging mold. I tried searching for a plain mold but all seem to have designs on them. I'm sure the States have far greater varieties available. The only plain one I've seen is the molds for plant markers which is too narrow for what you had in mind.

Here is a link that might be useful: Molds

Those molds look good but price may be a concern. Milk carton should work but you need many cartons as many bricks. Try to find a tin container, something like danish cookies/werthers etc, which has more or less same dimensions as milk carton does, but it must be rectangular. That way you can re-use it again and again. If you add very little water in the pre mix (so it's not 'runny'), then you can remove the mold immediately and brick shape should hold. (dont forget to water them when concrete sets in).

chowdhry, I thought the cement would have to set for a few days.

'don't forget to water them when concrete sets in"???

Really? so I should water the bricks as they set up, like with a watering can?

I have about 15 containers saved and my kids are saving for me too.

I do have some decorated tins that I packed away because I got tired of them and I think a few of them would be the right shape.

I believe you need to cover the concrete with plastic to keep it from drying out too fast and spray it with water as it is setting up to make it strong.

Sounds like an interesting idea! I have made things from hypertufa but not concrete. I'd like to see it when it is finished.

Here is a link that might be useful: My Country DIY Blog

What chowdhry is referring to is more of a dryer mix of the concrete. Certainly not wetter otherwise the mix would collapse if you remove them from the tins. However I am concerned about using tins. Often tins have these lips on the rims and so the opening is slightly smaller than the insides which would cause problems when removing the concrete. You might get a brick too large to be removed. So watch out for those kinds of rim. Also, I've seen cement stick to tins so releasing the brick can be problematic unless you line the tin with plastic but then that leaves a lot of lines from the folds of the plastics.

With milk cartons you get thicker bricks and essentially using up more concrete. So there's the disadvantage of using the form. More concrete in one form - less bricks you can make. However if you don't need a lot it's still a good way to go.

I believe there is something that's used - a spray to help release the concrete from the mold - it's used to 'grease' the mold before the concrete is poured in. Ask the hardware store about this.

And Sheryl is right about concrete curing - having done hypertufa myself. YOu need a curing period with plastic on the top to help get the concrete to fully cure otherwise - you get cracks.

Chowdhury described in her first response, a technique I've used to make my concrete materials - and it's something I would recommend. Build the mold out of 2x4 - no top nor bottom, and with a flat surface covered in plastic, you can easily make bricks and remove the mold as soon as the brick has hardened a bit. And cover with plastic to prevent fast drying. - The advantage is that you can easily remove the material and you may need less concrete to make the bricks. - And it's a technique still in use in countries that make mud bricks for houses.

I digress with this other thing technique I made some years before. I did the same thing as Chowdhury descriged, making a square mold with 2x2 and then I poured very smooth sand in the bottom and then I got my daughter to put in her footprint indentation. And then I poured the concrete mixture into it. Only my mixture was a wetter kind in order for the concrete to fill in the all the spaces. I had a relief of her footprint. The other thing I did was to put in seashell indentations and once again I got seas shells out of this technique. What's more the sand gave a nice texture to the block. Might be a something you can do at some point.

anyhow, good luck on your experimentations.

Thank you for all the feed back! Making the mold from 2x4 would be a quicker option than using milk cartons and a lot less clean-up:-)

I will post a picture when I finally get them made.

i have used cement before making things for the gardens. The big cement rings were made from the lids from fruit trays from the grocery store and I've used cat food dishes to make fish for the pond:-)

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some years ago in the accroutement area - we had a discussion on creating concrete objects out of soft ones. One member discussed creating a concrete pillow. You can, if you wish to pursue this hobby, look into creating more and more interesting sculptures for the garden. You can apply latex to soft objects such as pillows or stuffed animals and later use that as a mold for future projects. Just an interesting idea.

I make hypertufa "rocks" as a garden edge. I just plop a half shovel full into a plastic bag, twist and let cure for a couple of days. All my beds are edged with them.

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Here's a close up..

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They brown and green up after a few seasons with moss and lichen. and look quite natural

I had a thread on "hypertufa" forum a while back. Search 'Rocks' on that forum and it should pop up.

Wendy, I love those rocks:-) A lot easier than making bricks. I might have to change my way of thinking!

Hubby says why do need to go to all that trouble making bricks, I'll buy you a load of big rocks, LOL

Ha.. sounds like my own husband's response. Why? For the fun of making such things.

BTW - just learned that a way to release cement from the mold is to use oil spray. Spray the mold with it and your bricks will come loose easily.

Wendy, I went looking in the hypertufa forum and found the Rocks posts.

I have a question~~~Do you shape the mixture when it's in the plastic bag and put them where plan to use them?

Is the cement Portland cement?

How many rocks did you get from a bag of cement?

I guess I had 3 questions:-)

Hi Jo..yes, you can shape the mixture if you want to..I made a few with a "C" shape to go around curves.

Yes it's portland. I usually use an old dishpan as a measure, so my formula is 1 dishpan cement, one dishpan sand, one peat, one vermiculite. That blend would make approx 20 "rocks", with about 2/3 of the cement bag left.

Thanks Wendy, I think I can stop saving the cartons now, LOL I'm going to be bagging it:-) as soon as the weather warms up!

What a great discussion. Great idea, Wendy.