Hypertherm 65 Nozzle internal arcing?

[tony506]

I have noticed a few of my nozzles have been showing what looks like signs of arcing/pitting inside beside the opening.
Is this normal?
I am using fine cut nozzles on my HP powermax 65 on my plasmacam at 45amps, apprx 250ipm.
I have atttached a picture.
Thanks
Tony

[BrianMick]

perfectly normal.....
Brian

[OTHill]

That is one of my biggest holdups in cutting.The inside of the nozzle gets arced up and than will stop on a pierce.Than I have to restart.When I take my consumables apart and spin the electrode in the lathe and hold the nozzle over it letting it contact and spin for a while,it gets polished up and it's good for more cutting.Is it dirty air?

[tony506]

Thanks fellas,
I thought there was something wrong with my kit.
Thanks for the tip on cleaning the nozzle, I have a lathe and will do that.
Save me a few bucks as well.
Cheers
Tony

[OTHill]

Thanks fellas,
I thought there was something wrong with my kit.
Thanks for the tip on cleaning the nozzle, I have a lathe and will do that.
Save me a few bucks as well.
Cheers
Tony

For those that don't have a lathe a hand held drill will do as well.

[abmetal]

I use a small round wire brush that is designed for cleaning distributer cap sockets (where the spark plug wires push in). It's perfect for shining up the inside of the nozzles. Quick and easy.

Allen

[tony506]

Thanks Allen,
I will try and get one and use it.
Tony

[jimcolt]

Keep in mind that the dimensions on the Hypertherm consumable parts are critical. If you use a lathe, a drill, a tip cleaner to clean the inside of the nozzle or the face of the electrode you may get a few more starts out of them, but I guarantee the cut quality will change in terms of cut edge angularity and dross. It is best to lean the inside of a nozzle with a small piece of scotchbrite abarasive.....same with the front of the electrode.

The arcing inside the nozzle.....this is wear the arc starts. Temperatures can approach 20,000 degrees......so any small particles of "non-air" will immediately turn to carbon. fine oil droplets, moisture, particulates, grease from your fingers, etc) are what cause the discoloration....which is normal. These parts are called consumables for a reason....they do get consumed as they get used.

If you figure what you pay for a nozzle, divide it by the number of feet of material cut....you will (like me) probably decide that the 1/4 cent or so per foot that a nozzle costs (on a properly running Hypertherm) is a pretty low price for cutting. Spending your time cleaning the nozzle to get another 10% or so out of them may not be worth your time.

Jim Colt Hypertherm

[tony506]

Thanks Jim,
I understand the why and why nots now.
Tony