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Fluorinert Alternative?

Posted: Wed Jul 07, 2010 12:37 pm
by chad ramey
So, I've done some searching on the forum and haven't found too many posts on the topic of fluorinert, and certainly not any alternatives for it (as far as I've seen, if information is on here about the topic please redirect me). I'm interested in doing some gird cooling experiments and am right now caught in the search for a dielectric coolant that can handle ~50kv. Fluorinert has came highly recommended from most of the users that I have talked to, but it certainly is going to push my budget. Anywho.. I was wondering if any of you have heard of a possible cheaper alternative?


Re: Fluorinert Alternative?

Posted: Wed Jul 07, 2010 3:29 pm
by Doug Coulter
Lesker sells some Galden products that are about the same stuff, and have real good insulating properties in kv/mil.

Mostly they are lower boiling points than some of the higher Fluoinerts are (some of which were meant to fill vapor phase SMD soldering machines), but this may not be a big problem. They aren't too cheap though.

I believe that the stuff just isn't cheap or easy to make so it's all expensive. The nice thing is, you don't need much and it will not degrade if you keep it clean. So you could have a two loop system -- one very small with the inert stuff, coupling heat into something cheap, like water to finally get rid of certainly would not want to buy enough to fill an auto heater core/fan for the cooling side!

You might find a way to adapt some of the liquid coolers now used by gamers on hot computers?

Re: Fluorinert Alternative?

Posted: Wed Jul 07, 2010 5:15 pm
by Chris Roberts
You could always try reclaimed fluorinert. I bought about a gallon from TMC industries:

They primarily offer the service of reclaiming fluorinert that you send in, but they also had a stock of reclaimed stuff that one can buy from them. I called them and talked to someone about what they had on hand, and picked the most suitable one for my purposes. It still wasn't cheap, but it was a lot better than buying the stuff new.


Re: Fluorinert Alternative?

Posted: Wed Jul 07, 2010 7:41 pm
by John Futter
We use a form of kerosine that has been deoderised
comes from NEC in wisconsin its good for a least 100kV and is very cheap compared to fluoroinert

I have posted this before

Re: Fluorinert Alternative?

Posted: Wed Jul 07, 2010 9:02 pm
by derekm
You can deoderise kersoene by pumping it through BBQ charcoal.

Re: Fluorinert Alternative?

Posted: Thu Jul 08, 2010 2:29 pm
by chad ramey
Thanks guys. Upon further searching and with your advice I have decided that I'm going to buy small amounts of "non-conductive" computer coolant, deodorized kerosene, and I'll hopefully be receiving a small sample of FC-43 so I can compare them. Each fluid will be evaluated for it's dielectric and coolant qualities and from there I'll decide which fluid to use for large(r) scale experimentation. (And of course, I'll be sure to post my results on the forum)


Re: Fluorinert Alternative?

Posted: Thu Jul 08, 2010 5:51 pm
by Chris Seyfert
The deodorized kerosene will probably work well. If you can source it in the future, you may want to look into either Shell Diala AX, a good transformer oil, or possibly Envirotemp FR3, a biodegradeable insulating oil (more viscous, but higher water tolerance).

A word to the wise: whatever you use, keep it *very* clean and as dry as you can. A hundred PPM of water can drastically cut breakdown strength in hydrocarbon oil - according to one reference I have, down to only 20% of it's dry breakdown strength.

As for breakdown strength in general, there are two standardized tests: ASTM D877 and D1816. Both use AC volts, I believe. The D877 test is the oldest method, and is sort of a go/no-go test. It uses two 1" dia. disk electrodes spaced 0.1" apart. Good oil should test >30 kV.

The D1816 test is more applicable to general use, as it uses rounded electrodes, an oil stirrer, and either a .040 or .080" gap (1 or 2 mm). For Diala AX, typical good values are >28 kV and >56 kV for the gaps, respectively.

Hope this helps you on reading the data sheets and picking a good oil.

Re: Fluorinert Alternative?

Posted: Fri Jul 09, 2010 1:03 am
by lutzhoffman
As Doug already stated the Galden line is a good alternative. The Galden fluids are better than Fluorinert in for example high UV applications. The only weak point in these fluids can be the carbon bond, so the more oxygen there is with the fluorine in the molocule, then the more stable it is in general.

I have a laser which is cooled by Galden 110, and it has never gone acidic, or sparked over from the trigger pulses, great stuff in general. Simple is however always better, when it is possible, so the use of kerosine would be worth a shot, since the fluid can be isolated from UV ect.

If the system can tollerate some pressure then even a freon replacement fluid, with a closed evaporative system may work, Tetrafluoroethylene is very cheap, nonconductive, and very easy to find in everything from Dust-off to automobile AC cartridges. A small compressor can be pulled from any old fridge.

Re: Fluorinert Alternative?

Posted: Sat Jul 10, 2010 10:06 am
by Steven Sesselmann

Are you aware of Andrew Selzman's work? ... d-grid.htm


Re: Fluorinert Alternative?

Posted: Mon Sep 10, 2018 5:30 pm
by Fusion
Fluorinert does not work with silicone or viton seals/o-rings, Teflon is not recommended also, perhaps ceramics :(

Deodorised Kerosene works well with PTFE, viton or nitrile but not with silicone. Here in spain is sold to be used in heaters and cost 1€/liter.
Ethanol works well with nitrile o-rings but not with PTFE, viton or silicone.
Methanol well with PTFE silicone and nitrile but not Viton
Transformer oil: PTFE, viton and nitrile but not very well with silicone.

I supose kerosene is the best, can be used also to clean pieces before.
Can be used kerosene for cleaning pieces inside before using in vacuum?