Cutting - am I using the wrong tool?

[bricot]

I was trying to repair trailer and needed to cut off a 5/8" solid rod, bent in a V that holds chains going to a pivot, off of a piece of 3/8 square tube. The rod is laying flat on the surface of the square tube with the weld at 45 degrees. I have the Powerpro 205 and thought I would give the plasma cutter a try. Since I wasn't cutting completely through anything other than the weld, it seemed I got a lot of blowback and slag/arc on the tip.
Should I have turned up the air pressure? Used a torch instead?

Thanks

[geezer]

If you were cutting 5/8 flat bar you would have no problems, round bar is a PITA with plasma, best use a sawzall with a hack saw blade on that.

[bricot]

I was trying to cut the welds holding the round bar to the square tube, trying to to cut into the square tube below. I'm guessing its because cutting throught the weld you were into where the two surfaces (round bar, square stock) met and there wasn't enough room to blow the material out?

[I_Love_Plasma]

Well I have done this before. What I do is set the pressure to about 68-70PSI (air flowing). Then set my amps somewhere in between 25-30 amps. Then I strike my plasma flame and do my cursive "E's" like I was MIG welding it. It normally takes two passes like this. Sometimes it takes a third severance pass. If it still refuses to come off I just beat it to death cause I'm mad at it and it needs to come off anyway, this helps with any anger management issues I have hahahaha!



Hope this helps,
ILP

[bricot]

Well I have done this before. What I do is set the pressure to about 68-70PSI (air flowing). Then set my amps somewhere in between 25-30 amps. Then I strike my plasma flame and do my cursive "E's" like I was MIG welding it. It normally takes two passes like this. Sometimes it takes a third severance pass. If it still refuses to come off I just beat it to death cause I'm mad at it and it needs to come off anyway, this helps with any anger management issues I have hahahaha!



Hope this helps,
ILP

I may have had the amps up too high and probably only had the air at 60 at the regulator (not flowing). I didn't have a big enough hammer to work through my anger management issues . Of course we won't talk about the trailer getting back at me by flipping over while I was under it welding

[I_Love_Plasma]

I may have had the amps up too high and probably only had the air at 60 at the regulator (not flowing). I didn't have a big enough hammer to work through my anger management issues . Of course we won't talk about the trailer getting back at me by flipping over while I was under it welding

Okay, yeah try bumping up your pressure while flowing at least to 65ish with 27 or 28 amps. It's like a REALLY big industrial de-soldering unit

Ouch on the trailer!! That could have been a major injury.. Anger management hahaha, You are supposed to blurt out "can't touch this" as you grab the air-hammer and declare "hammer-time"!! LOL

ILP

[bricot]

No doubt!!