Does telescope cabinet colour matter?

[DaveHKent]

Currently I keep my telescope in one of the warmest rooms of the house, bungeed to the wall in a safe alcove between two book cases, but on these cold nights that is giving at least 20 degrees of cooling needed for each session. The best thing to do is for me to make a solid cabinet and store it in the garage where in winter it will be pretty close to external temperatures. I planned on painting it a metalic black, just because I thought it would look good.

However in the summer, my metal garage door faces south, heating the whole place like an oven. Basic physics teaches us that black absorbs more heat, but what if the cabinet is kept in the dark? The only radiation will be infrared. Does anyone think it would particularly make a difference painting it white? My feeling is no, but I thought I'd ask a collection of experts anyway

[wimvb]

In the garage it shouldn't matter. Light colours reflect more light, while dark colours absorb more. But if there is no light, there is no absorption.

You could provide openings for ventilation, though

[iapa]

Here is an experiment, from Scientific America, that examines the effect of different outside colourings of house - I expect that it would apply to this situation.

https://www.scientificamerican.com/article/bring-science-home-house-color-heat/

 

[Dave Lloyd]

25 minutes ago, iapa said:

Here is an experiment, from Scientific America, that examines the effect of different outside colourings of house - I expect that it would sexually apply to this situation.

https://www.scientificamerican.com/article/bring-science-home-house-color-heat/

 

Ha ha, specially apply I'm thinking. Darned predictive text eh?

[Bruce Leeroy]

I'd make a cabinet out of 100mm insulated board like this http://www.ebay.co.uk/itm/Insulation-Board-100mm-Celotex-Kingspan-8x4-/201816878653?hash=item2efd392e3d:g:yGwAAOSw~AVYoMCa

Initially I would make it air tight to stop any warm air entering the cabinet, add some moisture absorbing crystals and keep an eye on the mirrors/lenses, place cabinet in the coldest part of the garage...this method "should" help stop the mirrors dewing up.

[glowjet]

As you seem to be into DIY, Just make a simple box for the scope out of chipboard and line it with thick styrene sheet for insulation. Include a few; good sized cotton bags, filled with copies amounts of Cilica gel, to keep out the moisture, then Store in the garage all the year round. Paint it "Skybluepink" if you want to, I do not think it will make much difference to your scopes cool down time. 

I think you will find most, who have secure garage or shed storage facilities, store their equipment in this manner

[iapa]

5 hours ago, Dave Lloyd said:

Ha ha, specially apply I'm thinking. Darned predictive text eh?

removed possibly offensive term

[RichM63]

Skin flint at heart.  An old non functioning chest freezer from the salvage yard for free would fit your requirement. it has a fully insulated compartment, is sealed, can be painted any colour you want with no heat risk (ever felt the outside of a working freezer, it is not generally cold compared with the inside.)

[SilverAstro]

11 hours ago, DaveHKent said:

 The only radiation will be infrared. Does anyone think it would particularly make a difference painting it white? My feeling is no,

The scope is in a box in the garage and the colour of the box is the question ( not the colour of the garage or of the garage door ) ? have I got that right so far ?

In that case the colour of the box is of little or no consequence - I think ! -

- as the infrared radiation to it from the hot garage door and, less, from the warm walls will be small*  compared to the heating of the box by convection/conduction from the hot air inside the garage behaving like an oven. The box (and the scope inside) will be at the temperature of the inside of the garage if it has been there for some time regardless of its colour.  If it, the scope,  is in an insulated box it will just take longer to get up to or down to garage  temperature from when you first put it inside the garage, and/or it will be slow to follow changes in the garage internal temperature if insulated, or will be quicker if not insulated.

* and the direct infrared can be made smaller by putting the box far from the door (the door being a lot hotter than the walls!), at the back of the garage

If we were to contemplate the colour of the garage and of its door, and if or not the garage should be ventilated, that is a whole nuther post ! ?

 

[Stub Mandrel]

Get an IR thermometer, min was about £8 from Lidl. If nothing else you can amuse yourself taking the temperature of everything in the garden as you wait for the cloud to clear :-(

One thought, a mat black scopes will cool faster than a glossy white one, so why are 'posh' scopes always white?

[wimvb]

36 minutes ago, Stub Mandrel said:

...

One thought, a mat black scopes will cool faster than a glossy white one, so why are 'posh' scopes always white?

So they're easier to show off in the dark.

[SilverAstro]

1 hour ago, Stub Mandrel said:

 so why are 'posh' scopes always white?

So that when they are set up early in daylight/sunlight so that they can be easily admired by the neighbours they do not absorb too much heat from the sun.

 

[glowjet]

Stub Mandrel said: "Why are posh scopes always white"?

The simple answer is the manufacturers ran out of Black paint

[DaveHKent]

On 19/02/2017 at 17:55, glowjet said:

As you seem to be into DIY, Just make a simple box for the scope out of chipboard and line it with thick styrene sheet for insulation. Include a few; good sized cotton bags, filled with copies amounts of Cilica gel, to keep out the moisture, then Store in the garage all the year round. Paint it "Skybluepink" if you want to, I do not think it will make much difference to your scopes cool down time. 

I think you will find most, who have secure garage or shed storage facilities, store their equipment in this manner

Cheers, that is roughly what I was planning on doing. I wish I had thought ahead, I must have thrown out loads of gel bags recently.

 

Thanks to the others for your responses. I'll paint it the most aesthetically pleasing

[RichM63]

Damn, My Merc' is all black, my telescopes are black, my cameras are black and most of my misc' kit is also black.

I must be a real yokel.

[JOC]

18 hours ago, DaveHKent said:

Thanks to the others for your responses. I'll paint it the most aesthetically pleasing

Ooooo.............How artistic are you, you could put flowers and cartoon characters on it!!

You folks with boring white telescopes need a Skywatcher - many of these are like mine - done in snazzy black paint with a rather pleasing sparkly finish to it a bit like those posh tiles in airport duty free shops.  I didn't really mind what colour it was, but I was very chuffed when I opened up the box.

[Stub Mandrel]

I mustard-mitt I have a white scope :-)

It has 'Jessops' written on the side and was rescued from a mate's skip...

[wimvb]

11 hours ago, JOC said:

Ooooo.............How artistic are you, you could put flowers and cartoon characters on it!!

You folks with boring white telescopes need a Skywatcher - many of these are like mine - done in snazzy black paint with a rather pleasing sparkly finish to it a bit like those posh tiles in airport duty free shops.  I didn't really mind what colour it was, but I was very chuffed when I opened up the box.

Mine had extra sparkle last night. So had my camera.

(It showed better when I moved around it)