mica vs plastic pots

[Johnnyd]

Has anyone ever tried staining a mica pot to make it darker? Was thinking about trying it on the outside of a small mica pot with black wood stain.

 

[Lorax7]

Perhaps you could explain why a metal pot might get too hot, simply because it is metal (as opposed to black plastic, ceramic, or mica pots).

Photoelectric effect

 

[Melospiza]

"Specific heat" is the technical term you seek. Ever notice how a swimming pool can feel "cold," even if the water is actually the same temperature as the air? Water has a high specific heat (or, 'heat capacity') and can immediately take heat from your skin, causing it to feel colder. Your physical perception reflects your skin's temperature, not the actual temperature of the thing you are touching. In a hot oven, you can comfortably touch the cookies but not the metal baking sheet - they are the same temperature, but one has a better ability to give up some of that heat to your finger quickly!

I don't know what implications that may have for pots, but I wanted to point out that just because something "feels" hotter than something else does not mean that it actually has a higher temperature.

It is a combination of both specific heat and thermal conductivity. Specific heat is how much heat a material has, and conductivity is how fast it can move that heat from its interior. Concrete has twice the specific heat of steel, but steel feels hotter because it has 40 times the thermal conductivity of concrete. So (equal amounts of) hot steel will feel hotter than hot concrete at the same temperature, but the concrete will feel warmer for longer because it has more heat contained in it.

However, this only applies for a non-steady state process (touching a hot object, not holding it for a period of time). For this discussion, metal shouldn't be any hotter than mica or plastic, since the soil and roots are always in contact with the sides of the container. But the metal pot will heat up and cool down more rapidly than mica or plastic, which may have a negative effect on the plants roots (rapid water evaporation in a heat wave, freezing of the roots during brief frosts, which may not be felt in mica/ceramic pots).

 

[0soyoung]

Specific heat of water = 4.18 kJ/Kg.K

is about an order of magnitude higher than that of common metals (IOW it takes 10x the energy to raise water by one degree than to raise the temperature of these metals by one degree)​

Aluminum = 0.921 kJ/Kg.K​

yellow Brass = 0.401 kJ/Kg.K​

cast Iron = 0.461 kJ/Kg.K​

carbon Steel = 0.502 kJ/Kg.K​

304 stainless = 0.502 kJ/Kg.K​

430 stainless = 0.461 kJ/Kg.K
Copper = 0.377 kJ/Kg.K​

is about 3x that of solid plastics = 1.67 kJ/Kg.K​

and dry cement = 1.55 kJ/Kg.K​

is about 4x that of common brick, 0.9 to 1 kJ/Kg.K​

and stoneware = 0.8 kJ/Kg.K​

and vermiculite = 0.84 kJ/Kg.K​

​

 

[Melospiza]

Specific heat of water = 4.18 kJ/Kg.K

is about an order of magnitude higher than that of common metals (IOW it takes 10x the energy to raise water by one degree than to raise the temperature of these metals by one degree)​

Aluminum = 0.921 kJ/Kg.K​

yellow Brass = 0.401 kJ/Kg.K​

cast Iron = 0.461 kJ/Kg.K​

carbon Steel = 0.502 kJ/Kg.K​

304 stainless = 0.502 kJ/Kg.K​

430 stainless = 0.461 kJ/Kg.K​

Copper = 0.377 kJ/Kg.K​

is about 3x that of solid plastics = 1.67 kJ/Kg.K​

and dry cement = 1.55 kJ/Kg.K​

is about 4x that of common brick, 0.9 to 1 kJ/Kg.K​

and stoneware = 0.8 kJ/Kg.K​

and vermiculite = 0.84 kJ/Kg.K​

​

Yeah , thermal conductivity is a more important factor than specific heat.

 

[cheap_walmart_art]

How does mica compare to terracotta? Most of my stuff in training is in terracotta but ive been thinking about reporting into mica for aesthetic value. However, I know terracotta has a porousness that allows better air exchange, and ive had zero issues with cracking during my last two winters. Ive also been looking at these https://stonelantern.com/collections/bonsai-pots/products/tie-pots-for-growing-bonsai
Anyone have any experience with the tie pots?