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Question about Reflectix

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#51 maroubra_boy

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Posted 21 July 2023 - 04:14 PM

If it works well, then EXCELLENT result! :)

One layer, multi-layer, different materials, there is no right or wrong here, only what you find you need to do so to achieve the desired result.

It was good that you went with a multi layer way. Some people have tried one layer & because it didn't achieve what they expected they then blew off the whole insulation thing as rubbish, without thinking that things sometimes need some creative thinking on the part of the operator - but for some people unless you spell everything out they just don't think for themselves. And certainly don't expect them to look at using other materials besides Reflectix.

This is not an exact science as to there being one magic bullet. There are different grades of Reflectix & different climatic conditions that we use our scopes under. The more people experiment & post their work & results, the more we all learn.

One thing we need more of is people trying insulation wraps in the coldest of places. Here in Australia we don't see temps below -2°C unless it is under blizzard conditions. And insulation works just fine here. We need to see more people trying this in -10°C, -15°C & even colder. This pushes the limits of materials & scopes. And this requires people to think outside the box too.

Alex.

Edited by maroubra_boy, 21 July 2023 - 04:15 PM.


#52 maroubra_boy

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Posted 21 July 2023 - 04:34 PM

That dilemma is not a necessary one. No problem to properly insulate the tube and cover it with a topmost antireflection layer. Quite sure tha anti reflection layer must be the very surface.

I don't follow you here, my friend.

I don't use Reflectix or any shiny metalised materials in my insulation wraps. This is all about using something that works to insulate a Mak or SCT.

This is why I don't get into the technicalities of thermal properties of materials, because it confuses people & even can create & promote urban myths, of which in astro there is more than one for that matter.

I have used foam yoga mats & Coreflute to make my wraps. I tried a Reflectix type material once, a single layer on my 9" Mak & it didn't work and to add a second layer meant for a wrap that could not be removed - something I won't do is leave the wrap on the scope. So I stuck with the Coreflute & this stuff is much more robust than any Reflectix type of material.

I chanced upon insulating these scopes totally by chance. I needed to make a dewshield for the C8 I had at the time when I found a light blue yoga mat that was being thrown out. It was in great condition & my only thought was "Hmmm, this could work as a dewshield". I cut it to size, glued the ends together & slipped it on over the OTA. PRESTO! A great working dewshield. What took me a while to understand was why I was now not needing to wait for the scope to cool before ripping high magnification from it! It was Luxo that pointed out what I had achieved when I mentioned this curiosity to him! :)

Foam rubber is used in wetsuits & to insulate pipes & homes & many other instances, so why not a scope? Well, it works.

Don't get so caught up in the supposed properties of materials because we are not using ANY materials in any way that they were designed for. Our use of any material is totally outside the norm. The only thing that matters is if it works to insulate a scope, then that is all that matters. And if allows for easy installation & removal, even better.

Edited by maroubra_boy, 21 July 2023 - 05:42 PM.

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#53 Regulus 1.36

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Posted 21 July 2023 - 05:46 PM

This is just one layer. I might add a second layer underneath using a neoprene exercise mat.  Should I cover the face of the backend as well? 

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#54 maroubra_boy

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Posted 21 July 2023 - 07:13 PM

Some people do, but myself and others have not seen need to.

 

Pic below shows my 9" Mak with its Coreflute wrap - back end is butt naked...

 

By the way, the cables that can be seen running up the wrap, they are for the small 40mm 12V fan that I use to keep the corrector dew-free.  NO HEAT :)

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Edited by maroubra_boy, 21 July 2023 - 07:54 PM.

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#55 BKSo

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Posted 22 July 2023 - 10:45 AM

We need to see more people trying this in -10°C, -15°C & even colder. This pushes the limits of materials & scopes. And this requires people to think outside the box too.

Alex.


Here -10C to -15C is common in the winter. I store the scope indoors it takes 15-30 minutes for the scope to settle down. I am not sure if that is reasonable or not. The insulation is also effective delaying dew formation. For all night observing I am experimenting with a dew fan.

#56 quilty

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Posted 24 July 2023 - 02:38 AM

I don't follow you here, my friend.

I don't use Reflectix or any shiny metalised materials in my insulation wraps. This is all about using something that works to insulate a Mak or SCT.

This is why I don't get into the technicalities of thermal properties of materials, because it confuses people & even can create & promote urban myths, of which in astro there is more than one for that matter.

I have used foam yoga mats & Coreflute to make my wraps. I tried a Reflectix type material once, a single layer on my 9" Mak & it didn't work and to add a second layer meant for a wrap that could not be removed - something I won't do is leave the wrap on the scope. So I stuck with the Coreflute & this stuff is much more robust than any Reflectix type of material.

I chanced upon insulating these scopes totally by chance. I needed to make a dewshield for the C8 I had at the time when I found a light blue yoga mat that was being thrown out. It was in great condition & my only thought was "Hmmm, this could work as a dewshield". I cut it to size, glued the ends together & slipped it on over the OTA. PRESTO! A great working dewshield. What took me a while to understand was why I was now not needing to wait for the scope to cool before ripping high magnification from it! It was Luxo that pointed out what I had achieved when I mentioned this curiosity to him! smile.gif

Foam rubber is used in wetsuits & to insulate pipes & homes & many other instances, so why not a scope? Well, it works.

Don't get so caught up in the supposed properties of materials because we are not using ANY materials in any way that they were designed for. Our use of any material is totally outside the norm. The only thing that matters is if it works to insulate a scope, then that is all that matters. And if allows for easy installation & removal, even better.


Don't see your point.

Two things to consider 1. Insulation 2. heat loss by radiation. Both in order to avoid temperature drops inside the tube.
The second needs a reflecting surface. You can spare it but then the insulation layer must be thicker or more effective.
I do fine with 4mm insulation layer and reflecting surface.
Just read the outside temperature of a dark rubber foam on the scope's upside and its under side to find a delta of maybe 5 K or even more.
A reflecting surface avoids this delta.

(I did the test with my 4mm PE foam, one with reflective surface up the other down. After 1/4 hour the delta was 7 K, after 1 hour the delta reduced to 3 K constantly for the whole night.
What happened? The upside dark foam surface started to get wet (during the night it became dropping wet which I could see by the drops on the pavement)
And condensation warmth made the wet surface warmer than it would be without water deposition.
The good thing: The surface (if it was a mirror or corrector plate) is warmer than without dew on it, the bad thing: Tough it is warmer you can't properly watch through that mist layer.

Quite sure without that latent warmth the delta was more than 10K.

That much about the use of a reflective surface.

Edited by quilty, 24 July 2023 - 02:47 AM.


#57 Freezout

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Posted 24 July 2023 - 04:05 AM

My insulation is done with two materials.

 

I am sometimes frivolous and decided that reflectix wasn't beautiful enough for my dear Mak.

 

I used 3 layers of thick tape in a synthetic rubber material, branded Armaflex, fit to insulate industrial pipes against thermic changes and dew.

Above it I put a layer of heat barrier tape, because it has a nice gold color.

I left free some space for a dew heater to have stable temperature, but in fact I never use it.

Since then I have 0 dew on my telescope, while I live in a humid region. 

 

B6EA12CA-2F80-4B47-95E5-ED9C8E553DC2.jpeg


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#58 markmanner

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Posted 24 July 2023 - 07:12 AM

My insulation is done with two materials.

 

I am sometimes frivolous and decided that reflectix wasn't beautiful enough for my dear Mak.

 

 

I like that color!




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