Hi,
in light of the polysmooth kickstarter that promises a alcohol smoothable filament, I went ahead and dug out the rest of the limonene and hips that I had gotten for a dissolvable support and thought on how to use it to smooth HIPS printed parts.
My experience with dissolving the hips by completely immersing it in limonene directly were good, so I tested that vapor smoothing method. I took a mason jar put a teaspoon of limonene on the bottom and also put a drenched paper towel in as well.
However what came out was not what I expected, although I saw the inside of the glass getting foggy the smoothing effect with negligible.
I googled a bit but only found vidoes of support dissolving not smoothing with HIPS and limonene. So I wonder if someone tried the latter already and can report some results.
I would try complete immersion but limonene is not that cheap to buy a liter per color because of the solved material that conterminates the limonene and its also very fleeting. Over the year that I left it in the container I lost 60% and it was properly resealed. So I thought about how to conserve material and looked and the specific weight and other dilution material. It turns out its lighter than water and doesnt mix, so I could pour water into a jar, put some limonene on top and then just pull the object though the layer of limonene, maybe do that 4-5 times and observe how much smoothing I get every time.