I currently do my heat treat on carbon steels in my naturally aspirated gas forge with the assistance of a muffle. My muffle is the slightly shorter than my forge body. It is made of 2" square steel tubing w/1/4" thick walls and open at both ends. I want to run a thermocouple in it and I was told to run the TC through the top of my forge and into my muffle through holes drilled through the top of both. 2 Questions. 1) Can I run my TC from the back end of the forge into my muffle instead? 2) Would I gain any benefit from welding the back of the muffle closed? Thanks, DonO
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Gas forge Muffle question
- Thread starter PaMtnBkr
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Personally, I would drill through the side of the forge and muffle. There isn't much of a benefit to welding one end closed. I make my pipe a bit longer than the forge. Check out the post I made a while back...
http://www.bladeforums.com/forums/showthread.php/784221-Heat-Treat-Rig?highlight=muffle+rig
http://www.bladeforums.com/forums/showthread.php/784221-Heat-Treat-Rig?highlight=muffle+rig
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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I would use a long lead 8-12 gauge TC with ceramic separators for the leads ( see link). Stick it in the back of the muffle with the last 5-6" bent down.
Put the ceramic insulators on the part that will sit in the muffle, say 10", and bend the leads at 90 degrees. Slip on more spacers until there is about 1" of uncovered leads. Attach to the TC block, making sure the polarity is matched. Add the TC wires, making sure the polarity is matched. Plug TC plug into controller, making sure polarity is matched.
You should place it with the tip in the general area of the blade bevels. It can lay on the blade, next to it, under it, etc. Only the tip reads the temperature, so that placement is what is important.
This is 16" long and 12 gauge :
http://www.ebay.com/itm/K-Thermocou...659?pt=LH_DefaultDomain_0&hash=item19da88ef5b
Auberins has it up to 12" in 8 gauge.:
http://www.auberins.com/index.php?main_page=product_info&cPath=20_3&products_id=39
Put the ceramic insulators on the part that will sit in the muffle, say 10", and bend the leads at 90 degrees. Slip on more spacers until there is about 1" of uncovered leads. Attach to the TC block, making sure the polarity is matched. Add the TC wires, making sure the polarity is matched. Plug TC plug into controller, making sure polarity is matched.
You should place it with the tip in the general area of the blade bevels. It can lay on the blade, next to it, under it, etc. Only the tip reads the temperature, so that placement is what is important.
This is 16" long and 12 gauge :
http://www.ebay.com/itm/K-Thermocou...659?pt=LH_DefaultDomain_0&hash=item19da88ef5b
Auberins has it up to 12" in 8 gauge.:
http://www.auberins.com/index.php?main_page=product_info&cPath=20_3&products_id=39
Last edited:
I just looked at what you posted Stacy and this is exactly what I have except I got them through McMaster-Carr and they came w/the little insulated ceramic tubes like as is shown on the e-Bay link. Are the leads soldered onto the actual probes? If so, i'll have to get that done. Thanks again. glad I m on the right path.