dross build up on shield

[TWSalaska]

Hello all I am having a problem with dross building up on the top of the plate when I am cutting. Could this be because I am cutting pig iron (rusty crap steel) ? its 3/16 and I am cutting at 130 ipm I run a burn table in a fabrication shop and have to get parts cut on time so am forced to cut higher speeds. I am using a PM 105 on a 5x10 icon elite table (fast cut CNC). I feel as if this is damaging my nozzles. please help

[TWSalaska]

it happens when I try to get the dang machine to cut at the recommended .06 cut height. to figure that out I setup a 4x4 cut and turned the THC off and watched the volts and set it to the volts it was running at and well it just does not seem to work right. any suggestions?

[Zippo]

Generally a worn nozzle, excessive cutting speed, or a high standoff is usually the cause, What does your cut look like? as in bevel and kerf, (wide top or bottom)
And yes build up will change your quality of cut and blow tips faster. One never knows could cure the issue by a simple 5 or 10 ipm drop

[TWSalaska]

I get a slight wider gap at top so the side of the part is like \ but a slight bevel although enough to annoy me . I cut parts for 30+ people in the fabrication shop so a lot of pressure on me... I have to set my cut height the same as my pierce height or it will dive down so quick and try and run through the dross before it clears the start point. so I am running my 3/16 at 140 ipm . 125 volts 65 amp. pierce delay is .5 and pierce height is 1.6 . any other suggestions ill try dropping speed a few IPM first.

[Zippo]

I am not real up on Hypertherm Powermax 105 , I think you might want to go to "TECH TIPS" in the board index an explain it to JimColt he the Hypertherm contact
http://www.plasmaspider.com/viewtopic.php?f=89&t=13969

[WyoGreen]

Since you're cutting at the same height that you are piercing at, I'd say you're cutting too high. If your torch is diving before the pierce is finished, you could try increasing your pierce delay a bit and see if that helps.

[BrianMick]

You can use an anti spatter spray that will help......do not spray directly on the consumables. spray it on a rag and wipe it on your shield.
Brian

[AnotherDano]

You can use an anti spatter spray that will help......do not spray directly on the consumables. spray it on a rag and wipe it on your shield.
Brian

Do some price checking.
What your wife has in the kitchen will work also.
PAM or any other vegetable cooking spray.

[TWSalaska]

well I use a thc so after it pierces it goes down to the set voltage for cut height and I have all that anti spatter spray I could want I work in a fabrication shop for Alaska's oilfields. the higher cut height per say is just so it doesn't shoot right down into the molten dross. the whole plasma table still confuses me lol but hey what can u do .

[jimcolt]

Proper pierce height (higher is better) and a slight coat of anti-spatter on the shield will effectively keep the spatter from building up. Piercing too close (closer that the specs in your Hypertherm operators manual) will build up spatter quickly. Cut height is critical if you want minimal edge taper. If the torch dives into the plate....there is likely a "peirce delay" or AVC (arc voltage control) delay setting that is set incorrectly. I suggest talking with the machine supplier regarding the height control diving. The most important part of a cnc plasma is the height control....if you want the best cut quality and the best consumable parts life.

Jim Colt Hypertherm

well I use a thc so after it pierces it goes down to the set voltage for cut height and I have all that anti spatter spray I could want I work in a fabrication shop for Alaska's oilfields. the higher cut height per say is just so it doesn't shoot right down into the molten dross. the whole plasma table still confuses me lol but hey what can u do .

[TWSalaska]

Thank you all for your help. I have mentioned this to them and they recommended that I just set my cut height at the same height as pierce lol this machine has been a ongoing battle maybe it is because this is my first time but I feel like I am working bugs out every day.

[Largemouthlou]

That answer don't sound right at all from your table company!! hey need to pay your consumable and clean up time bill!! LOL

On another note, I never knew your not supposed to spray anti splatter on nozzle. I usually put on appropriate sheild, drop in nozzle, electrode, then spray with a little anti splatter, Im sure it is getting on the nozzle this way. So what happens to the nozzle if it gets some on it??

[jimcolt]

Lightly spray anti spatter spray on the front of the shield.....if a little goes in the shield orifice and gets on the nozzle it is ok.....if a lot goes in it will cause misfiring. Do not use anti spatter dip on a plasma torch.

I am testing a new technology ceramic spray.....may be just the ticket for keeping spatter off the shield...

Jim Colt Hypertherm

[TWSalaska]

I tried some of the ceramic spray when we got the machine and its actually not to bad. The shop stopped using it because the welders where using it so fast it was costing to much lol.

[tm america]

Simple fix use mig nozzle spray on your consumables and shield.. does wonders for keeping things from sticking to it