The tubing is welded. I don't think soldering would hold in this application. It was fabricated from two 90 degree Aeroquip adapters.
As for the fitting in the pan, I used a washer kit from Doty manufacturing that is made specifically for this application. It is a large aluminum washer that is relieved for an "O" ring on the inner circumference.
http://dotymi.comGarth's method or mine each require some welding although it is minor and any welding shop would likely do it for a minimal charge. I would think that a longer piece of braided steel line could be looped under the oil filter in place of the steel line I used and would eliminate any welding but the line would have to be supported so it doesn't rub somewhere.
