Author Topic: Non-heat conductive poking tool  (Read 1133 times)

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Offline ransonjd

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Non-heat conductive poking tool
« on: February 16, 2018, 02:03:57 am »
Any suggestions for a non-heat conductive, non-melting, non combustible tool that can be used to push parts under hot air rework?

Thanks,

John
 

Offline jeremy

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Re: Non-heat conductive poking tool
« Reply #1 on: February 16, 2018, 02:53:07 am »
Google “ceramic tipped tweezers”

Stainless dental picks or stainless tweezers is what I use though. Stainless steel doesn’t have very good thermal conductivity, and if you use something small and thin the conductivity is reduced even further.
 

Offline ransonjd

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Re: Non-heat conductive poking tool
« Reply #2 on: February 16, 2018, 06:19:55 am »
I've considered ceramic tweezers, but I'll admit I'm looking for something more like a ceramic tipped pick or probe. Essentially, a stick with a ceramic end with a fine point.

 

Offline thm_w

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Re: Non-heat conductive poking tool
« Reply #3 on: February 16, 2018, 10:03:06 am »
What would be the advantage of the ceramic tip over stainless?
Unless you are poking the thing for minutes at a time, I can't see much heat conducting.

https://www.kismetmosaic.com/products/dental-pick-set
 
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Offline ransonjd

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Re: Non-heat conductive poking tool
« Reply #4 on: February 17, 2018, 01:22:45 am »
Yesterday I removed a small leadless IC with a thermal pad tied to four ground planes on a lead-free board. Even with a preheater and hot air, it took ages to get off the board. Since I was working under a microscope, I could only move my stainless tool so far away before I lost sight of it, and the air bouncing off the board heated it up. It got hot. This is my use case.

Yes, the technically correct, but more expensive answer is a bigger preheater.
 
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Offline ralphrmartin

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Re: Non-heat conductive poking tool
« Reply #5 on: February 17, 2018, 03:49:08 am »
I've considered ceramic tweezers, but I'll admit I'm looking for something more like a ceramic tipped pick or probe. Essentially, a stick with a ceramic end with a fine point.

Cut a pair of tweezers in half?  :D
 

Offline SeanB

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Re: Non-heat conductive poking tool
« Reply #6 on: February 17, 2018, 06:08:52 pm »
PTFE rod, with the end machined down to a blunt tip. Works well at reflow temperatures, and generally does not char unless you are going stupid hot on the point. Buy a length around pencil diameter of solid or glass filled PTFE and use an automatic pencil sharpener on it.
 
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Offline GerryBags

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Re: Non-heat conductive poking tool
« Reply #7 on: February 19, 2018, 11:58:52 am »
I have some titanium needles, one with a nice glass blob on the end, which are used far (ahem) dabbing shatter... but never mind that, they can take ridiculous amounts of heating and cooling without ill effects.
 

Offline apelly

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Re: Non-heat conductive poking tool
« Reply #8 on: February 19, 2018, 12:12:41 pm »
I want to say "sharpen a stick"

But I confess, I didn't read the thread.
I'd rather a Google clue, link, or some theory than "do this" (generally)
 

Offline ransonjd

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Re: Non-heat conductive poking tool
« Reply #9 on: February 19, 2018, 01:44:10 pm »
I've tried a sharp stick. While I enjoy the smell of wood smoke, I fear that my wife is going to think that I've accidentally lit the house on fire.
 

Offline jmelson

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Re: Non-heat conductive poking tool
« Reply #10 on: February 20, 2018, 10:00:11 am »
I use an X-acto knife.  The tiny contact area of the point prevents heat transfer.  The stainless is VERY unlikely to accept solder.  Works like a charm.

Jon
 
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Offline AllTheGearNoIdea

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Re: Non-heat conductive poking tool
« Reply #11 on: February 21, 2018, 03:03:59 am »
Glass rod - been used in labs for +100 years
AllTheGearNoIdea Where Its All About The Gear
 

Offline KL27x

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Re: Non-heat conductive poking tool
« Reply #12 on: February 24, 2018, 03:52:53 pm »
Quote
Yesterday I removed a small leadless IC with a thermal pad tied to four ground planes on a lead-free board. Even with a preheater and hot air, it took ages to get off the board. Since I was working under a microscope, I could only move my stainless tool so far away before I lost sight of it, and the air bouncing off the board heated it up. It got hot. This is my use case.

Sometimes you have room, perhaps, to just nudge the part with the side of the hot air nozzle, itself. I'll do this with the inside lip of the nozzle. The air flow has thus far been enough to prevent a part from sticking inside the nozzle or falling inside and blowing out the TRIAC, lol. 
 

Offline JonM

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Re: Non-heat conductive poking tool
« Reply #13 on: February 25, 2018, 03:17:26 pm »
Ceramic tubes or rods could be good. I used to use them for ion optics assemblies and probably have some in my materials bin. I will move some to a toolbox thanks to this topic.

McMaster-Carr has a 1/8" dia, 12" long tube for $14.70. Ceramic would have a "more square" end than glass that has been fire polished to not be dangerous. The ceramic tube or rod would probably be a superior probe for the purposes of pushing a component off of a board.
 

Offline Doctorandus_P

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Re: Non-heat conductive poking tool
« Reply #14 on: May 25, 2018, 01:07:34 pm »
Bit late, but I find it strange ceramic screwdrivers are not mentioned.
https://www.aliexpress.com/wholesale?SearchText=ceramic+screwdriver
Orignally these were designed for adjusting HF inductors / capacitors because of their non magnetic / conductive properties, but because of the hardness of ceramics they stand up really well to all kind of abuse.
(Untill they break, that is one of the few ways to wreck them).
 


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