Portland cement/sand or plain Portland with fiberglass cloth

[Joe Dupre']

I have several square yards of 4 oz. fiberglass cloth left over from a kayak project and figured I'd try to make some sort of free form pot. I have a long and narrow button bush clump that needs a rather unusual pot size and figured I'd give it a go. I plan on soaking the cloth in the cement/sand mixture or just the plain cement and laying it over some kind of plastic covered form. After a bit of drying, I'd maybe build up the thickness a little. Anyone have experience with this type of construction? I really don't know if cement alone would be strong enough.

 

[Brian Van Fleet]

Hydrated cement paste will set up, but may be brittle and have low flexural strength. Coarse sand will make it stronger.

 

[Joe Dupre']

Thanks, Brian.

 

[Coppersdad]

This might get you started.

 

[Joe Dupre']

Cool. I'll give it a try.

 

[Coppersdad]

Cool. I'll give it a try.

Joe, I hope you will decide to post your results. I saw this kind of gardening pot made by a gardening enthusiast in my area. She made larger pots and painted them. She used the pots to garden on her deck. She actually used bath towels as the form for some of the larger ones.
She was just about to start using a concrete coloring product instead of paint. I've not been able to see her results with that product.

 

[Wires_Guy_wires]

If you don't want them to be too heavy, go with tile glue. It's 20x more expensive, but it weighs nearly nothing. So my untrained eye, the tile glue is as strong as concrete.

 

[Ruben Bouwmeester]

If you don't want them to be too heavy, go with tile glue. It's 20x more expensive, but it weighs nearly nothing. So my untrained eye, the tile glue is as strong as concrete.

Not in my opinion. Concrete is stronger. If you want too reduce weight, there is lightweight concrete it has those ball in it that creates a nice texture. I believe these are made from it https://ibuki-shop.com (rock creations)

 

[my nellie]

Hello,
I have experimented and used different mixtures for creating some pots. Just for the fun of it and for my own pleasure and enjoyment
1) Papercrete = Lightweight cement + shredded and soaked paper + fine grained sand + latex (adhesion promoter) + powder coloring (% of ingredients as per instructions on the internet)
2) Lightweight cement + latex (adhesion promoter) + shredded glass fiber + fine grained sand + powder coloring
3) Lightweight cement + colored tile glue + latex (adhesion promoter) + coarse sand + powder coloring
With all three mixtures I used a metal mesh over which I "constructed" the pot and even when using molds I incorporated mesh.
Dry ingredients should be well mixed all together and then water and any other liquid (combined) are added.

 

[Leo in N E Illinois]

I recommend application of concrete mix in a single application. Layers will spall, delaminate, and flake away after freeze thaw cycles.

Sand & Portland cement is stronger than Portland cement paste alone. Sand, aggregate and cement is even stronger, but for pots, sand & cement are good enough for pots.

Applications, such as pot making, use the cement-latex blend sold for vertical patching of concrete. It allows thin patching or thin pots.

Concrete considers any use less massive than 4 inches, (10 cm) to be a thin application. Fibers, preferably plastic or fiberglass, are essential for strength. If fibers can be felt protruding from the pot surface, sand the surface smooth with sandpaper, the fibers will not be detectable after sanding.

For pots or slabs much over 8 inches or 20 cm in any direction should have metal mesh or an armature constructed and imbedded in the slab or pot when pouring the concrete. It will prevent breakage. I had a 10 inch slab that was only supported internally by fiberglass webbing break in half on me after one winter outdoors. Hardware cloth for smaller pieces, heavier support for larger pieces.

 

[Drew]

Hello,
I have experimented and used different mixtures for creating some pots. Just for the fun of it and for my own pleasure and enjoyment
1) Papercrete = Lightweight cement + shredded and soaked paper + fine grained sand + latex (adhesion promoter) + powder coloring (% of ingredients as per instructions on the internet)
2) Lightweight cement + latex (adhesion promoter) + shredded glass fiber + fine grained sand + powder coloring
3) Lightweight cement + colored tile glue + latex (adhesion promoter) + coarse sand + powder coloring
With all three mixtures I used a metal mesh over which I "constructed" the pot and even when using molds I incorporated mesh.
Dry ingredients should be well mixed all together and then water and any other liquid (combined) are added.

Can you show us some pictures of some of the forms/pots you have made with the above ingredients?

 

[Anthony]

This was a gift, made of cement and fine sand,
Mould was a plastic ice-cream container,
Feet made by fitting a piece of oiled wood to the bottom
of the container. The wood had two projections for drainage
holes.

All you had to do was pour in the cement and an oiled block of wood
was added for the internal space.
Stone added to the top of the wood to keep it down.
Made back in early 90;s.
Still in use.

One tip - soak cast shape in water for 6 weeks.
Change the water twice or so.
Good Day
Anthony

We use porous pots for pines, cement or earthenware.
Soil is 5 mm silica based gravel plus 2 or 3 parts aged compost.

 

[my nellie]

Can you show us some pictures of some of the forms/pots you have made with the above ingredients?

Well, of course. But you will be disappointed by the outcome

 

[my nellie]

Please, remember an amateur's work, just for my amusement...

 

[my nellie]

Colourful bottle caps to shape the legs

Sorry, no images of the preceding stages

 

[Crawforde]

Nice.
I imagine they will look great with some age and mosses and lichens on them.

 

[my nellie]

Thank you for your kind words @Crawforde
Mosses and lichens are impossible to grow in my region/climate.
I have made some attempts in the past to grow them on to substrate in pots, I failed and then I gave up on them.

 

[Crawforde]

Sorry,
But I bet they will look nice with some trees in them!
I think I’m going to try making some.
I wonder if you could try some Thyme and keep it cut short to look like moss?

 

[my nellie]

... ...But I bet they will look nice with some trees in them!... ...

Indeed, some of them have trees planted into them. I will try to shoot some photos and update my post
But taking into account that these are meant to be training pots then the result is definitely more pleasing than the plastic pots.
Regarding Thyme (or other plant) I think that the roots would mess with the tree's root system. Mosses don't have roots.

 

[Coppersdad]

Thank you for your kind words @Crawforde
Mosses and lichens are impossible to grow in my region/climate.
I have made some attempts in the past to grow them on to substrate in pots, I failed and then I gave up on them.

How about ferns? There are some very tiny species...