Sorry, but I disagree with most of this, especially the single wall prints part. I think the default min wall settings for most slicers is 2. Why in the world would you not want to print multiple walls?
I also take issue with the over-generalization of PLA is not designed for "any load or stress". It's all about what kind of load, how much stress, where and how those forces are applied as well as the design.
But regardless, you haven't addressed the OP's use case. Floats will not take any load or stress, so PLA would be fit for purpose by your definition.
You absolutely can do single wall prints. Vase mode in Prusaslicer is a great example.
2-3 walls is the default setting for a 0.4 nozzle on various slicers, resulting in a wall thickness of about 1.2mm(depending on layer height setting). Personally, I am a 10 wall guy resulting in 4-4.5mm thick walls for everything I make no matter what my infill setting is. For floats or anything that needs reduced water intrusion that would affect buoyancy, 10 walls is the way to go.
I wasn't generalizing PLA at all. I am referring to the
LW-PLA the OP is inquiring about to make buoyant components and floats.
LW-PLA is a Specialty PLA formulated, that when extruded, it increases its volume about 3 times reducing its weight 50% by the varied density. For instance, to get a 0.4 wall thickness with
LW-PLA, you have to adjust flow down to 50% or less and vary the nozzle temp. At normal flow at a higher temp your wall can end up 1mm to 1.2mm with a single wall count.
LW-PLA is a specialty filament that takes a bit of fiddling with design and settings to get right.
LW-PLA's intended use is for thin, lightweight, single wall parts for model planes, car bodies and cosplay costume pieces. the parts are are not structurally sound and will only take light loads and stress. So you might get a light part, but it wont withstand any water pressure at depth. Regular PLA is a much better choice.
As I stated earlier in my original statement that "this filament would give no benefit". What I thought was implied was "
LW-PLA offers no benefit over regular PLA or any other filament of choice". Hope that clears things up for everyone.
The
LW-PLA is really cool stuff. Check out YouTube for instructional videos on settings, design and what people are making with this filament.