Welding Tips and Tricks

To the point mobile weld limited to 110 or 115 house current what ever you want to call it. Dynasty 200 have run up to 145 amps no problem at this location on 110.have a 1/4" flat plate to 1/8" tube weld to make a T weld. I have a digital infra red thermometer how much temp should I put into this piece for pre heat? I know getting max amps out of the machine would help or a gas mix but its not applicable. I do have a source to pre heat though. Any help would be appreciated.

Typically, you really shouldn't preheat aluminum more than 250-300 deg. At 400+ deg. you start getting into the critical range for changing microstructure. Do you know what grade aluminum you are welding?

I have no idea what material it is but its not been or is to be heat treated.

200 degree's is adequate. Not sure if you're setup for this or not but a little helium (20%) will go a long way in extending the 110v capability of that dynasty. Use a temp crayon, a infrared thermometer won't be very accurate on the aluminum.

thanks to you guys for the info.

Ji Gantor wrote:Hi Guys,
I have an infared thermometer and find them inaccurate on aluminium.
You can adjust the settings but I have found that does not represent the true temp of the material.
I pre-heat to a little over 100 degs C say 120 C. In the begining I used a 120 C heat crayon but now just use water.
This is easily tested, just drip a drop of water on the material, if the drop boils and vaporizes than it is over 100 C.

Ji

I don't have a IR thermometer (well an ultra cheapo) But do have a thermal cam.
Aluminum is very reflective of IR, and a bit of wrinkled foil is used to calibrate the cam at each use.
Crayons or a thermocouple/meter reading being best bet IMOHO.