Hoping for help understanding how to replicate a type of container I just saw! (unique 'blocky' container)

[SU2]

I use way more cement/portland than sand

Whoa that's very interesting! I'd gotten the 2.5:1 sandortland ratio by posting about this (specifying the usage-case) on a masonry forum (reddit.com/r/stonemasonry), although as mentioned I've found myself making it more portland-rich each batch....have you ever worked with such sand-heavy mixes? Would love to hear any comments/thoughts you have on any differences between the two that haven't been covered in general terms, like I'm incredibly satisfied with my first pots (which are actively in-use) that were the 2.5:1, though the more portland-rich ones (not in-use yet) seem far 'tighter' aesthetically (and literally, I would imagine), like more of a 'gloss' than 'matte', for lack of a better analogy...what of the extreme, of pure portland? I'm guessing there's some minimum% of sand/aggregate that's needed for strength, right? Or are aggregates *only* for filler? (or filler plus stuff that's irrelevant to us, such as compaction ratings- obviously rocks in the mix give better compression-ratings but that'd be irrelevant here!)

And as 2/3 much water as the cement, volume wise. 1 cup of sand, 2 or 3 cups of portland/cement, 1.5-2 cups of water.
It makes a wet slurry, and again, it doesn't dry fast at all.

My drying periods take from somewhere close to 4 days up until 2 weeks. When they're dry, they usually easily pop out of molds.

Whoa....I'm going to have to make a little batch of what you make to see how runny this stuff is!! I'm pretty fussy about making my mud as dry as possible, and while the degree I go here is because of slouching in the forms, even if I were making a free-hand slab or something (assuming the runny-ness of the wet mix didn't matter) I'd be afraid to use a too-wet mix because I've always understood it as the water that leaves during curing just leaves cavities, like if you add more water to your mud you'd be able to make a larger ball out of that bucket of mud, but it wouldn't be as dense as if you'd only added enough water to sufficiently activate the portland; there'd be a porosity from where the excessive water once was but no longer is.
It sounds like you use a very wet mix, for purposes of ease-of-forming / working-with, and that the finished product comes out great- I've gotta be misunderstanding something, either my original understandings of how water-volume impacts final product or in how you're doing it (though I'm quite sure I get your method now, am just so confused because it goes against all I thought I'd known about cement- I only have low-level experience w/ the stuff so could've misunderstood how important it was, but I'd sworn you needed to be real wary of too-wet a mix because the cured product would be weak- maybe your using a cement-rich mud makes things different?) Am pretty sure I'm wrong on some important part of the water/portland/curing process here, if you're able to spot it I'd love to be corrected

As for the 3D software, I found I used Autodesk. I don't know if it's still free, or if it ever was, I only know I never paid for it.
With that 3D software (and corresponding converter) you can print every design layer by layer.
Google sketchup is still on my pc, but it needs updating I don't want to take time for, so that's an unanswered possibility.

If that doesn't work, there's always wood, silicone and plastic. I've never tried silicone though! But it seems like the ideal material for casting, since it's flexible and therefore reusable. Some sillicones can even be baked in the oven without losing their properties.

lol- does it work on linux? I don't have any non-linux machinery in my house so that'd probably negate any popular software, really would like an excuse to 3D print something (am near-enough big cities/universities that there's *gotta* be pay-to-use machines somewhere nearby!) but expect I'd spend far too-long on this and have way too many projects ATM...using wood, stacking cardboard and wrapping it w/ saran-wrap, forming its edges w/ caulking/silicone, etc, stuff like that should make decent inside-forms and really I'm not too worried about the aesthetics of the pot interiors, in my current setup I only 'finish' the lip/edge of the pot, all work done to the inside is to grind-off the slouch to increase container volume, ends up looking terrible lol! Plus I do huge 'slopes' to my drainage holes, looks like crap but it's neat knowing the ~1" holes have at least an inch of slope in all directions feeding them

Regular "hand" soap can be made out of KOH or NaOH mixed with oil. The bars of soap we all have somehwere laying around.. Or the stuff that you pump from a container. If you have the NaOH type (which is the cheapest, most sold, most used, most preferred) then it shouldn't be used for pots. The sodium (Na) isn't that loved by most plants, that's the #1 reason why plants don't love sea water. It's the surfaction you want, not the dissolving of fats caused by the oil+lye result. That means dishwashing soap/detergent, or shampoo. Shampoo contains a lot of extra chemical stuff that sound very chemical, and they sound very unhealthy. But most of those molecules come from nature, or they are adaptations from natural products. These can usually be broken down easily since 99% of them are carbon based and water soluble. As for dishwashing detergent, it's basically the same. Just don't over use it. A few drops should suffice.
Most of the chemicals in dishwashing detergent are meant to 'capture' salts, like EDTA. That shouldn't bother us a lot, it's the surfactants we are looking for. If you can get a hold of some Tween, it would be even better.

Whoa, thanks! Am good at some chemistry but totally ignorant of other areas, soap being one - and it's something I'd fear researching, just because of the links to nefarious purposes, so really appreciate this break-down right here...am going to need to read that many times to fully absorb/remember it but as mentioned I've always just thought 'soap is soap' so I buy the cheapest and use it for everything (body/clothes/dishes), had no clue there was real difference in 'types' like this (my approach has always worked at least ;p )
[and yeah I'm not remotely one of those to be 'afraid of chemicals' in ignorance, not reading dihydrogen-monoxide and thinking 'stay away!' lol, I treat glyphosate with care but no I don't fall for the 'chemical names are bad' trap many do, I know valerinic(sp?) acid from valerian-root was the starting point for scary diazepam(valium), I learned a lot of this type of stuff managing a GNC for a couple years, probably the only positive thing I can say about that experience of ripping-off customers all day long :/ Still feel guilty for that..]

As for dyes, I'm clueless about those. A thin layer of concrete paint on a piece of cloth, or maybe even a sponge would have the same effect, leave some protection and is way cheaper. I'm just a poor guy trying to find a way around the high costs of this hobby. I like to think in alternatives instead of barriers ;-)
Pieces of glass incorporated in the concrete maybe? Pieces of molten plastic? Using transparent or dyed epoxy to fill cracks? I see a lot of potential. More than I can ever do on my own.

Your pots look nice though! You have a lot more than I have right now!

I'll have to take a pic of my shelf it's close to 20 now iirc, gotta make another batch asap because my forms-box is building-up quick lol!! I've been messing with very dilute paint ('stain' lol) and am getting somewhere, I hate them not being 'raw' but just anticipate a bad result if there's no barrier whatsoever on the outside...
And yeah I know what you mean, I like collecting/propagating my own trees but I also have to, I could never afford this hobby if it wasn't an entire DIY project, from plant-acquisition to containers, from the scrap/salvaged wood used on my benches to making my own substrates (perlite & DE are the only things I buy that are 'ready', I also get lava rock & bark mulch that I process myself....ugh! Fantastic quality-control, at least ;p ) All about getting rid of the plastic containers & colanders, some specimen are bigger than I'm ready to build them containers with mortar so I've been doing a new method for boxes when needed, mostly full-bottom wide-gauge screening, next box I've got ideas on putting a 'stripe' 1/3 the height of the box that'd be metal-mesh like the bottom of my last one, max aeration



Thanks again for all the infos in this thread man, very appreciated! (just checked username to verify you were male- 'wire guy wires' lol, you probably wouldn't have spoken to me if you knew how little I've wired in my life ;P I'm only a year in so very few of my trees need wire, most are just being grown-out- am actually just now hitting a point where I've got ~1yr old trees that are looking like bushes-on-a-stump, that I've gotta learn how to properly start training!! As if there's not enough projects on my bonsai-list right now lol

 

[Tentakelaertje]

Lol pottenbakkers = potters. English is an easy language for most of the time.

By floral foam, do you mean "oase"? We always call it oase haha. If dry, wouldn't that suck out the moisture from the concrete way too quickly? And if wet, moisturize the concrete making it more of a water ballet than a casting? Do post the results, ok!?

 

[Wires_Guy_wires]

Lol pottenbakkers = potters. English is an easy language for most of the time.

By floral foam, do you mean "oase"? We always call it oase haha. If dry, wouldn't that suck out the moisture from the concrete way too quickly? And if wet, moisturize the concrete making it more of a water ballet than a casting? Do post the results, ok!?

Oase is one of the brands. Make the foam wet so it keeps its shape, and wrap it in clingwrap/vershoudfolie. It should stick tightly because of the water-foam-plastic adhesion. If wrapped right, there's no leakage of concrete.
All parts can be connected together with some simple tooth picks.