I guess it’s true what they say, about the second time being ‘the charm’ (oh, wait). Cause this time everything went according to plan, and I got four new concrete bird baths for about thirty minutes of work, approx. $4 concrete, $2 Pam spray, and a little under $20 of plastic bowls from the dollar store.
But first, the steps to get there.
So, you can disregard the brush pack for now, as the Pam being spray doesn’t require brush application.
Anyway, I bought eight plastic bowls of varying sizes, between $2–4 each. Based on an experiment with plant trays in Vol. I of this series, I’m feeling like it’s simpler if you purchase two bowls of one larger and one smaller size, rather than sandwiching between two of the same size. I suppose technically you can probably do it (and I’ll try at some future point), but it seems simpler just to use the smaller size as the void inside the larger. And there’s a saying I like very much, which I think holds true here as well:
The easy way is hard enough.
What you see here is the various form bowls after having been sprayed with Pam. The smaller bowls are flipped upside down, because we need to apply the release (oil) to their exterior face, and to the interior face of the larger containing bowls.
Gotta say the Pam spray is way easier (and a fraction of the price) compared to the mineral/butcher block oil which the Home Depot video originally recommended me. You can get a nice thick fat spray, easily and rapidly covering all the surfaces. I don’t see any reason to go back to a brush-applied oil at this level of experience (maybe there’s some esoteric benefit I haven’t encountered yet).
Also depicted is a large bucket of clean water (disclosure: I totally used dirty gross rainwater from a barrel last time, despite the instructions on the bag to use clean water only), and then a 2 liter ice cream tub which I use to roughly measure out water to add to the concrete mix.
Cut the bag open, and dump it out into the wheelbarrow without inhaling the dust (it will harden when exposed to moisture — also presumably functions in your lungs?).
This “all purpose” mix has some little rocks in it, which I thought at first would be bad somehow, but when the pieces are dried, you don’t really see them. I guess they just held give structure?
I saw some people doing this trough method on Youtube? I guess it works fine. This mix says it takes 3 liters of water.
That’s what 3 liters of water yielded. I’m just using an ordinary garden hoe to mix. I didn’t think this mix seemed liquid enough, so I eyeballed and added approximately another half liter of water. The bag says to add water in small quantities so you don’t overdo it (can confirm over-doing is easy — see Vol. I).
Anyway, I ended up with this, which seemed acceptable to me:
Your mileage may vary. This seemed “right” to me. I’m certainly not an expert, as this is only my second try playing with concrete on my own.
A word about tools. All I had last time for small tools was the garden hand shovel at left, which is actually probably all your need, and a bigger shovel to plop into your forms. I bought the small trowel just cause it seemed cool and I thought might enable me to do something down the road.
That’s the bigger shovel, and mix ready to deploy.
I tried using the trowel to make a nice smoother cake-batter style top, and that seemed very clever.
Trying to show that the bottom surface of the inner bowl is passing below the “water line” of the concrete here. The bowls have a slight tendency to rise up, so better to weight them down while the curing is taking place.
I didn’t want to end up without enough mix, so I tried to evenly divide up the remainder globs into the three bowls.
And poured off the rest of my water bucket carefully to clean and soak the tools in the wheelbarrow.
The fun part is that this is an extremely simple and straight-forward procedure — especially if you’re using plastic forms like this.
So back to the clever cake batter thing a second:
After trying that a second time, and remember that I’d read somewhere to tap your forms to settle air bubbles, I realized that this tapping process if you go round the bowls seems to also flatten down the surface, so you don’t really even need to trowel anything at this stage (though it’s kinda fun).
Again, just trying to show you need to push down into the concrete, so your inner bottom faces is below the top level of the concrete. I was really nervous about pushing down too far and ending up with a too thin bottom (or even cracking through). But it just seems like all you need to do is not go crazy while pushing down, and then just stick your weights and forget about it.
Leave the forms to dry at least overnight. I’m not sure what’s optimal waiting period. Probably more like 24 hrs, though observationally after about three days they seem to reach another level of dryness, followed by another more complete level attained at around a week (granted, I’ve only done this in one other experimental batch).
Anyway, for these, I did them around 5pm one afternoon, and pulled the top bowls out around 10am the following morning. Being plastic, and fully Pammed up, the top bowls lifted out no problem, and the forms seemed solid enough (though not fully dry), that I felt adventurous enough to (using gloves, cause they’re oily) flip them over carefully and pull off the outer bowls. With a very small amount of jiggling, they separated no problem. Which is awesome.
Since the first one was so easy, I did all the rest. Note, if the first one broke, I probably would have stopped and waited longer for the rest to dry.
But there was no problem at all.
Anybody could do this.
And there you have it. Once you have the basic technique, and the right materials (plastic, in other words), there’s pretty much nothing to it.
I’ll probably let these dry for a week, and then apply (with a brush) the waterproofing seal which will ensure these can serve their intended purpose of holding water.
I want to make at least two more sets of four. Which, now that I know I can get four of these size out of one bag of concrete, this is pretty easy to plan for. I will probably experiment with buying some other types of concrete mix, just for comparison. But I think I’ll only change that one variable, which is important when doing this kind of physical experiment, until you really understand how all the contributing factors interplay.
I have basically two gardens of a bit over 10,000 sq. ft. each under varying degrees of wild cultivation. I’m creating and installing these “dollar bird baths” (estimated price of each in materials) as water sources, so I can get a few different wild garden habitat certifications, like potentially:
- Canadian Wildlife Federation: Garden Habitat Certification
- National Wildlife Foundation: Certified Wildlife Habitat
- Monarch Watch: Monarch Waystation Certification
There are probably some others out there as well, and I’ll poke around for them. I know the animals don’t really care about certifications, but if I get them, it means I can purchase and install signage on the property as well which promotes the idea that, hm, maybe wild spaces are not only things that we can encourage and integrate into our lives, but that somehow sustain us too in the process.