[Jetboy]

You really should start with about 1-1.5 /16ths of an inch. Maybe even an 1/8 in of gap. With the pipe butted together you'll have a very difficult time getting adequate penetration. It's probably best to bevel the ends, but in that size and thickness of pipe a small gap will work fine. Now if you were dealing with 1/2" wall tube, you'd never get a good welt without beveling the edges. It's definately possible to crank up the heat and penetrate all the way, but it's not going to work all that well. It may be beyond the capacity of your welder to do that, but I've never used a 175 so I don't know. Anyway, try it with a small gap and you'll get better results. Good luck.