Friday, July 7, 2023

Plasma Cutter

Today's generation of welders prefer a plasma cutter to a cutting torch whenever possible. I'd have to agree. If it's near by, it is generally worth the effort of hooking up and using when you are looking for a precision cut. 

My brother Luke bought me this Hypertherm 45 when I graduated from seminary. There are other good brands out there, but Hypertherm has plasma cutters dialed in. 

They take a pretty good air compressor to run. It's also best to run a regulator keeping it under 150psi and a filter to ensure for clean air. 

Our project this was to build two flanges for Dad's new irrigation pump. I had some 3/8 plate around so we went to work.

Anytime you can scribe the holes and perimeter for accuracy go for it. Here we used a bent nail to get a basic template. 

The marks were super faint so we then outlined them with soap stone. 

Ready to cut. 

Often it takes a quick second for the arc to penetrate the metal. But if the sparks keep flying in your face you might have a bad tip. 

When you change a tip on a plasma cutter you have to change the electrode dilly at the same time. 


Here's a little tip: when I blow holes I start the arc in the middle of the marked hole, so that if you loose your chalk line you always have a reference point to work around. 

The cool thing about a plasma cutter is you can cut any kind of metal that will conduct electricity. Here we cut this 4" steel nipple in half to weld on to our plate. 

When your working with something that is going to involve pressure I always prep the surfaces as best I can. Of course, remove the paint from the nipple, but also the new metal sheen that comes on the plate. 

Tack weld it in four corners, but not right where the holes are, because they are already gonna be close to the bolt head. 

Then go for it. I don't start or stop a weld on top of a tack weld or a hole. And when I overlap the other end of the weld, I always run over the top of it to ensure a good seal. 

One beauty of plasma cutters is that they don't produce a lot of slag, and what they do produce is easy to remove. I don't run the grinder on top of the slag, but just underneath it so that it, more or less, pops off. 

One of the greatest features of plasma cutters is their low heat. In a project like this where the mating surface is important, you really have to watch for warping. The little curling that occurred here will not impact our final application.

Time to install. We built two of these threaded flanges, one 3" and the other 4". We then placed a gasket in between the surfaces as we bolted it up. 

Giddy up. 

Mission accomplished. This could have been done with a cutting torch and I suppose we could have ordered some new flanges on Amazon and had them delivered to the ranch. But what fun would that have been.  With the right tools and a little bit of savvy, we had a couple of pump flanges built in no time. It would have been hard to do as smoothly, though, without a plasma cutter. They may not get used everyday. But when you need them, they are great to have on hand. Hopefully Dad will come around to this modern means of welding. But you know what they say, it's hard to teach old cowboys new tricks. 

1 comment:

  1. "My brother Luke bought me this Hypertherm 45 when I graduated from seminary."

    I wager you are the only Priest who can say that.


St. Anthony

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