Help !!!

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Hi,    I am no expert in welding. But for my research project, I am trying to weld a thermocouple onto a steel plate. I tried spot welding the wire to the plate. The steel plate is quite thick with a lot of mass and hence has a high thermal capacity. As a result, I am not able to get the steel hot enough to make a weld. On the other hand if I hold the spot welder for too long, I end up frying the Thermocouple wires. Can anyone please suggest me an alternate method to weld? (note : I was very particular about spot welding because, I dont wanna leave a blob around the weld as the experiment concerns very sensitive heat measurements and a blob might cause differences in Thermal conductivity)
Reply:I'd use O/A  torch with no filler.  If you can't get weld puddle, you're doing something wrong, then slip the thermocouple wire in.If that doesn't work, I'd silver solder the wire or braze it on.Good luck.
Reply:Not sure I picture exactly what you are doing mechanically, but I'd think about "tinning" the steel with a soldering or brazing material that has thermal conductivity that is equal to or greater than the steel.  And has a relatively low melting point.  The bond the thermocouple to that."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by jsrirammHi,    I am no expert in welding. But for my research project, I am trying to weld a thermocouple onto a steel plate. I tried spot welding the wire to the plate. The steel plate is quite thick with a lot of mass and hence has a high thermal capacity. As a result, I am not able to get the steel hot enough to make a weld. On the other hand if I hold the spot welder for too long, I end up frying the Thermocouple wires. Can anyone please suggest me an alternate method to weld? (note : I was very particular about spot welding because, I dont wanna leave a blob around the weld as the experiment concerns very sensitive heat measurements and a blob might cause differences in Thermal conductivity)
Reply:I m sorry. What exactly is a O/A torch btw? Thanks
Reply:Preheat the steel ...
Reply:Originally Posted by jsrirammI m sorry. What exactly is a O/A torch btw? Thanks