# Corflute heat mat to heat aquarium from underneath?



## Renenet (Apr 2, 2013)

Hi, 

I have been exploring ways to heat the aquarium I am setting up for my stimmie. I live in Cairns, so won't need to heat continuously. I only want to give her belly heat for the cooler winter days and when she has to digest.

The aquarium is sitting on this stand:







I have a sheet of polystyrene foam between the stand and the aquarium.

I am thinking of making a heat mat from Corflute and a heat cord, as described in a couple of other threads, and sticking it under the aquarium. That's assuming I can track down 10 mm Corflute. My questions are: 

1) Would I need an insulating layer between the glass and the mat to stop the glass cracking and/or snake burning?
2) What should I use for the insulating layer?
3) Any suggestions on how to hold it in place? 
4) Any better ideas?

Thanks,
Ren


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## imported_Varanus (Apr 2, 2013)

I used a similar set up with 20W heat cord (in a cooler ambient) and found I needed a thermostat to control temps accurately, probe placed between corflute and enclosure floor. Maybe a lower wattage heat cord would suffice, without a thermo? In the end, I opted for the "ReptaheatMat with Temp Controller", given the price of dedicated thermostats (not sure if this is an option for you, though?).

1) I would think not, just between mat and enclosure stand: bottom of enclosure/ mat/ insulation/ stand.
2) Styrofoam sheeting- 10mm or thicker. You may need a base board for your stand?
3) Weight of the enclosure should hold it down.
4) Sounds like a plan! For my only other suggestion, see above.

Hope this helps?!


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## Snowman (Apr 2, 2013)

Cant answer the other questions, but I use 10mm coreflute a lot. It's bloody hard to track down. You can get it from BFS plastics in QLD, I'm getting them to ship some to perth.


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## Bluetongue1 (Apr 2, 2013)

The temperature will not worry the glass. You can put a cold glass plate into a sink of near boiling water without a problem. However, tip boiling water onto part of the plate and it may crack. Rapid localised expansion or contraction can put undue stress on adjacent areas that have not expanded or contracted. Given the temperatures you will be dealing with, this won’t be a problem. 

Sit the coreflute on the glass base in the stand, cut out a piece of plywood or styrefoam of the same thickness, such as it covers the rest of the glass base. Then sit the aquarium directly on that. You can also place a slate tile inside the aquarium and directly above the coreflute mat. This will provide a more natural heating surface and looks better than bare glass or news paper etc. 

Have you considered placing the corflute inside the aquarium and a slate til on top of it? I realise that leaves an exposed section of heat cord to deal with. This can be routed up the corner of two adjacent sides and a piece of electrical conduit slipped over the top.

I am not a fan of heat mats in general but the flat black cord types are a huge improvement on the bag types, of which some should simply not be sold for safety reasons. Anyway, you can get a 7W unit or so which might be ample for your needs up their. 

Blue


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## andynic07 (Apr 2, 2013)

Snowman said:


> Cant answer the other questions, but I use 10mm coreflute a lot. It's bloody hard to track down. You can get it from BFS plastics in QLD, I'm getting them to ship some to perth.


I believe transport companies use it a lot to go between the gates and the freight on taughtliners .


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## disintegratus (Apr 2, 2013)

andynic07 said:


> I believe transport companies use it a lot to go between the gates and the freight on taughtliners .



No, 10mm corflute is expensive. Transport companies are, by and wide, a cheap lot (5 years experience in the industry taught me that, you practically have to sign your life away for a cheap nasty pen, let alone anything else). They tend to use the really thin stuff, or at best 6mm or so. A signwriting mob might be your best bet. If you're not fussed about what it looks like, they might even have some offcuts or misprinted signs they'd give you for cheaper, or even free.


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## andynic07 (Apr 2, 2013)

disintegratus said:


> No, 10mm corflute is expensive. Transport companies are, by and wide, a cheap lot (5 years experience in the industry taught me that, you practically have to sign your life away for a cheap nasty pen, let alone anything else). They tend to use the really thin stuff, or at best 6mm or so. A signwriting mob might be your best bet. If you're not fussed about what it looks like, they might even have some offcuts or misprinted signs they'd give you for cheaper, or even free.


I was thinking that you could find out from a transport company where they buy it from.


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## bigjoediver (Apr 2, 2013)

Those thin heat mats are designed to go under glass vivaria/aquariums so unless you have a heat cord laying around, by the time you get some core flute and buy a heat cord you could get a 14w heat mat off eBay for the same price. Just put aquarium on 10mm foam and put mat in between and put a thermostat probe in contact with the mat. If you get a name brand one from the pet shops that is the directions given on how to set it up.


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## imported_Varanus (Apr 2, 2013)

Gotta love Gumtree, Ebay, etc!


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## Renenet (Apr 2, 2013)

Thanks for the suggestions. 



bigjoediver said:


> Just put aquarium on 10mm foam and put mat in between and put a thermostat probe in contact with the mat. If you get a name brand one from the pet shops that is the directions given on how to set it up.



Is there some risk that sandwiching a heat mat between the glass and the foam sheet will cause a fire because excess heat can't escape?


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## Snowman (Apr 2, 2013)

disintegratus said:


> No, 10mm corflute is expensive. Transport companies are, by and wide, a cheap lot (5 years experience in the industry taught me that, you practically have to sign your life away for a cheap nasty pen, let alone anything else). They tend to use the really thin stuff, or at best 6mm or so. A signwriting mob might be your best bet. If you're not fussed about what it looks like, they might even have some offcuts or misprinted signs they'd give you for cheaper, or even free.


Yep even the sign companies are not using 10mm as much. All the ones I called only stock up to 6mm. The only place I can find 10mm in Australia is from plastic manufactures and distributors.


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## imported_Varanus (Apr 2, 2013)

If you carefully remove the black plastic capping at the end of the heat cord, it will fit in smaller sized corflute panels. I've done this with a panel placed in the bottom of a Lace monitor nest box.


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## fourexes (Apr 2, 2013)

I've got 8mm and it fits the cords I have. Purchased from bunnings it's expensive for a sheet as I used the polycarb roof sheeting but one sheet should last almost your entire herping career if not make some cash on the side  I drill mine every 20mm or so down every runner the cord runs down to prevent heat retention then suspend the whole assembly facing the holes down. This provide a warm hide underneath and a basking spot on top, which is supplemented by a heat globe through the day leaving plenty of room for ventilation over and under. 

Can post pics if necessary but I'm sure I stole the idea from someone on here anyway :lol:

edit: with more focus on your original post I also run one of the same mats as I mentioned before, under a plastic tub sitting on melamine with the holes facing up, and a gap between the mat and tub.


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## andynic07 (Apr 2, 2013)

fourexes said:


> Can post pics if necessary but I'm sure I stole the idea from someone on here anyway :lol:


Yes please (photos)


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## Snowman (Apr 2, 2013)

andynic07 said:


> Yes please (photos)



http://www.aussiepythons.com/forum/general-reptile-discussion-42/radiant-heat-panels-181687/


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## Snowman (Apr 2, 2013)

Above is a link to my first heat panel DIY. 
Here is some I was working on Easter weekend. This is using a 80w cord and the coreflute panel is 500mm long. 
I don't drill any holes as I if find that heating the air in the tubes 
makes the panel a lot warmer. As heat chords get warmer in warmer environments. I still use a pulse proportional thermostat though it gets to a max of 45 degrees on top of the shelf un regulated but not the whole enclosure.
The vivs are 1800L 400H 600W


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## Bluetongue1 (Apr 3, 2013)

Renenet said:


> ….Is there some risk that sandwiching a heat mat between the glass and the foam sheet will cause a fire because excess heat can't escape?


The ‘sandwich’ of materials surrounding the heat mat will determine the potential rate at which heat can move away from the heat mat. This sandwich includes whatever is in the aquarium and sitting on the glass above the mat. The rate at which heat will actually move depends on this and the heat differential (difference in temperature) between the mat and where the ambient temperature inside and outside the aquarium. The matt wattage will determine the amount of heat generated by the mat – higher wattage means more heat. 

I am sure anything 15W or less should be fine without an air gap. However, it is worth checking out on the packaging instructions at a pet shop and then with a decent thermometer once it has been running for a few days and the temps have stabilised. Heat is transferred in three possible ways… *Conduction:* Heat moves through a substance; *Convection:* Heat is carried in a moving current e.g. hot air rises; *Radiation:* Hot objects give off infrared rays (IR) of light. When objects absorb IR they heat up. No air gap means no you are eliminating convection and forcing all heat transfer from the mat to occur primarily through conduction (you get some IR transfer through the glass). So depending what goes over the warm glass area inside the aquarium, this could have a significant effect on the temperature the mat gets to.

Blue


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## fourexes (Apr 3, 2013)

Snowman said:


> Above is a link to my first heat panel DIY.
> Here is some I was working on Easter weekend....



I had a vague idea it was you I stole the idea off in the first place lol. Thanks snowman.

Here are some pics as requested, just to add to the plethora of information added by snow. And to add, I only drill holes in the runs with the cord inside to evacuate 'mass heat' all the others are undrilled. If I could I would cross drill the whole lot parallel to the the top and bottom sheets and only drill the faces of the runs with no cord then it would dissipate better. For now, this works with little hassle.


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## Renenet (Apr 3, 2013)

Thanks, Snowman, Blue and Fourexes. 

Fourexes: Is that Corflute or polycarbonate roof sheeting you're using in that mat?


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## Snowman (Apr 3, 2013)

fourexes said:


> I had a vague idea it was you I stole the idea off in the first place lol. Thanks snowman.
> 
> Here are some pics as requested, just to add to the plethora of information added by snow. And to add, I only drill holes in the runs with the cord inside to evacuate 'mass heat' all the others are undrilled. If I could I would cross drill the whole lot parallel to the the top and bottom sheets and only drill the faces of the runs with no cord then it would dissipate better. For now, this works with little hassle.


Looks good. I've been thinking of using the poly to make racks with.


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## fourexes (Apr 3, 2013)

yes as mentioned earlier it's poly-carb roof sheets. expensive but if you know enough near by herpers could be very cost effective. works very well for me. I do notice if you run an infa-red thermo across it with the thermostat at say 30 the heat runs get to around 38 and the others measured close up are around 35. I've turned the thermostat to 28 and I get a temp on the heat runs of 35 and the others around 32. when measured from say 6 inches away the local temp measures 32. Something to think about when setting up, if it makes sense, sorry if it doesn't.


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## J-A-X (Apr 3, 2013)

The difference you are seeing in the temp is because you haven't, or aren't able to, calibrate you infRa-red (not infa red) temperature gun. 
They are not just point and shoot like many people use them. 
You need to calibrate the gun for different emissivity of the object you are trying to test. 
For those that are curious- here's the definition of emissivity:

The emissivity of a material is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. A true black body would have an ε = 1 while any real object would have ε < 1. Emissivity is a dimensionless quantity.

In general, the duller and blacker a material is, the closer its emissivity is to 1. The more reflective a material is, the lower its emissivity. Highly polished silver has an emissivity of about 0.02.

End of definition ! 

In laymans terms it measures the reflected heat, not actual surface temp. I always set my heat up with a common mercury thermometer WHERE THE REPTILE WILL BE. Thus avoiding any possibility of burns. 
I have an IR gun that I regularly use to check my heatcords are working as it doesn't disturb the animal 

Like they say 'a little knowledge can be a dangerous thing ' and to use only an IR gun could result in your animal having a less than optimal basking spot 

I know this is off topic but IR guns have been mentioned a lot recently and this seemed an ideal time to get this info out there.


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## Renenet (Apr 3, 2013)

J-A-X said:


> I know this is off topic topic but IR guns have been mentioned a lot recently and this seemed an ideal time to get this info out there.



No worries, Jax. This thread has turned out to be more informative than I thought it would be!


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## Snowman (Apr 3, 2013)

Most of the name brand temp guns are very accurate though. I've tested my fluke with the high tec thermometers at a processing plant and got readings within .2 degrees. I trust my fluke temp gun more than my digital and mercury thermometers.


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## andynic07 (Apr 3, 2013)

Snowman said:


> Most of the name brand temp guns are very accurate though. I've tested my fluke with the high tec thermometers at a processing plant and got readings within .2 degrees. I trust my fluke temp gun more than my digital and mercury thermometers.


Are mercury thermometers more designed for ambient air temperature rather than surface temperature?


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## Snowman (Apr 3, 2013)

J-A-X said:


> The difference you are seeing in the temp is because you haven't, or aren't able to, calibrate you infRa-red (not infa red) temperature gun.
> They are not just point and shoot like many people use them.
> You need to calibrate the gun for different emissivity of the object you are trying to test.
> For those that are curious- here's the definition of emissivity:
> ...


Five Ways to Determine Emissivity
There are five ways to determine the emissivity of the material, to ensure accurate temperature measurements:
Heat a sample of the material to a known temperature, using a precise sensor, and measure the temperature using the IR instrument. Then adjust the emissivity value to force the indicator to display the correct temperature.
For relatively low temperatures (up to 500°F), a piece of masking tape, with an emissivity of 0.95, can be measured. Then adjust the emissivity value to force the indicator to display the correct temperature of the material.
For high temperature measurements, a hole (depth of which is at least 6 times the diameter) can be drilled into the object. This hole acts as a blackbody with emissivity of 1.0. Measure the temperature in the hole, then adjust the emissivity to force the indicator to display the correct temperature of the material.
If the material, or a portion of it, can be coated, a dull black paint will have an emissivity of approx. 1.0. Measure the temperature of the paint, then adjust the emissivity to force the indicator to display the correct temperature.
Standardized emissivity values for most materials are available (see pages 114-115). These can be entered into the instrument to estimate the material’s emissivity value.


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## Snowman (Apr 3, 2013)

andynic07 said:


> Are mercury thermometers more designed for ambient air temperature rather than surface temperature?


They would certainly be affected by ambient air temps.


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## Snowman (Apr 3, 2013)

The other thing with temp guns is that laser pointer is just that. A pointer. The sample area is like a cone and you get the average temps within that cone sample. The red dot is not the exact spot you are measuring. 
Unless the surface is quite reflective you shouldn't get any false readings.


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## andynic07 (Apr 3, 2013)

Snowman said:


> Five Ways to Determine Emissivity
> There are five ways to determine the emissivity of the material, to ensure accurate temperature measurements:
> Heat a sample of the material to a known temperature, using a precise sensor, and measure the temperature using the IR instrument. Then adjust the emissivity value to force the indicator to display the correct temperature.
> For relatively low temperatures (up to 500°F), a piece of masking tape, with an emissivity of 0.95, can be measured. Then adjust the emissivity value to force the indicator to display the correct temperature of the material.
> ...


Certainly like to do your homework or have a really broad knowledge base.


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## Snowman (Apr 3, 2013)

Cut and paste... Like Jax did


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## J-A-X (Apr 3, 2013)

LOL, maybe we should start another thread  
Given I use no other heating than cords the merc thermometers are giving me accurate enough temps, I also have a digital probe thermometer to triple check because I don't run thermostats (and that's a separate thread on its own) 

I'm not saying dont use IR guns, just wanted people to be aware that they could need to be calibrated. 
I've 'played' around with mine and on some surfaces they can show 5 degree less than the mercury or digital thermometer - enough to cause severe irritation to a snake belly when I think it's 35c and its actually 40c


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## Renenet (Apr 3, 2013)

fourexes said:


> yes as mentioned earlier it's poly-carb roof sheets. expensive but if you know enough near by herpers could be very cost effective.



Can you please tell me the measurements of that sheet? I'm trying to get any idea of how far away the cord "channels" are from each other.


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## fourexes (Apr 4, 2013)

calibrated or not I was only using it to compare the difference in surface heat on the one surface, just looking for hot spots, which were noted. Then as mentioned measuring from a distance (increasing the measuring area) gave me a comparable average.

Thanks for the info though Jax that was informative. 

I agree mercury thermometers are great, but basically anything can be inaccurate if not used properly. 


Renenet: The sheet size was 600 x 2400mm with 8mm squares, available from bunnings in the roofing section if you want a good look.


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