I get several years out of a cartridge. The only time I had issues was 
after the first one failed on trap one. It was difficult to remove and 
as a result it widened the opening. After some trials (~2000-2001) of 
using foil only or compound only and having them fail almost immediately 
to lasting a week or so, the combination solved the problem and now they 
last many years. Perhaps I have replaced them once each since then.

David

On 5/13/2016 12:06 PM, Matthew Lachniet wrote:
> Hi all,
>
> How long do your heater cartridges and thermocouples routinely last?
>
> I usually have to replace every 6-12 months with no use of compound. I used the fan for several years but it never seemed to make a difference so I removed it when it failed.
>
> Fortunately it is dry in the Mojave Desert so ice and water isn't so much an issue.
>
> Matt
>
> Matthew Lachniet
> Professor of Geoscience
> University of Nevada Las Vegas
>
> -----Original Message-----
> From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of David A. Mucciarone
> Sent: Friday, May 13, 2016 11:58 AM
> To: [log in to unmask]
> Subject: Re: [ISOGEOCHEM] Frequently broken heater and thermocouple of Kiel
>
> The thermal joint compound I use is from Type 120, Wakefield Engineering, Beverly, MA 01915, 781-406-3000. I did not Google it, hopefully you can do that part. For what it is worth, I tried just using the compound (no fan) only without using the foil and the cartridge failed early, better than without, but early nonetheless.
>
> Good luck,
>
> Dave
>
> On 5/12/2016 3:43 PM, zhangd wrote:
>> Dear David, Andy and others:
>>
>> Thanks you for the suggestions. I am going to use fan and the
>> conducting compound. What brand of that compound you use, David?
>>
>> Thanks.
>>
>> Dachun
>>
>>
>>
>> On 2016-05-12 14:47, David Mucciarone wrote:
>>> I'm not sure what KC you have so this may or may not be helpful.
>>> Depending on how the previous heat cartridges came out it is possible
>>> that during removal the hole enlarged. If this happened, water can
>>> work it's way in and cause early failure. This happened on my KCIII.
>>> The solution was to shim with copper soil (had it on hand, other foil
>>> could be used), given the thickness of my foil, I simply wrapped the
>>> cartridge with one layer of foil to provide a snug fit. I then used a
>>> conducting compound to seal the top. This is a non hardening
>>> compound, I am on the road, but will be in the lab, hopefully on
>>> Friday (if my flight ever gets off the ground) in the event you need
>>> more info on this potential solution.
>>>
>>> David
>>>
>>> Sent via the Samsung GALAXY S®4, an AT&T 4G LTE smartphone
>>>
>>>   -------- Original message --------
>>>   From: zhangd <[log in to unmask]>
>>>   Date: 05/12/2016 14:55 (GMT-05:00)
>>>   To: [log in to unmask]
>>>   Subject: Frequently broken heater and thermocouple of Kiel
>>>
>>> Dear Colleagues:
>>>
>>>   Both the new heating cartridge and measuring resistor in our Kiel
>>> device  trap 1 are broken (not the same time) in less than two month.
>>> It  happened twice already. Any suggestions would be appreciated.
>>>
>>>   Thanks.
>>>
>>>   Dachun Zhang
>>>   ESS dept UCI
>> .
>>
>
> --
> Mailing address:
> David A. Mucciarone
> 473 Via Ortega, Rm. 140
> Stanford, CA 94305
> 650-723-0817(O), 650-804-6403(M)
>
> Ship to address:
> David A. Mucciarone
> 367 Panama Street, Rm. 50
> Stanford, CA 94305
> .
>


-- 
Mailing address:
David A. Mucciarone
473 Via Ortega, Rm. 140
Stanford, CA 94305
650-723-0817(O), 650-804-6403(M)

Ship to address:
David A. Mucciarone
367 Panama Street, Rm. 50
Stanford, CA 94305