Durn plasma cutter glued my steel art together

I was figuring Id make some xmas presents of some neat steel art.. I bght 1/16" mild steel and cut four blanks and clamped themn together. Well after i cut out the shapes the dang pieces are now welded together..Im gonna hafta get the dang grinder and grind the edges to make em come apart.

Im using a very old plasma cutter,16 yrs old, and thght it wld do alright..Shoot.

Well i ordrerd a new Hypertherm 600. Shld be here nest week.

Maybe I need to place spacers betwen the blanks.

Any ideas of this problems sports fans??

BR

Reply to
bluedog
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Is the plasma cutter 16 years-old, or are you?

You do understand how a plasma cutter functions, don't you?

Unless you go to some very thick spacers, say 1/4", I really don't believe that they are going to help very much, in several ways.

Harry C.

Reply to
hhc314

I used one abt 3 yrs ago to cut 2 kegs. thats all. I guess i dont understand how it works.

However, i am not going abandon my idea to cut out several pieces at once.

Reply to
bluedog

I have not heard of people successfully cutting out multiple pieces with a plasma cutter. I think that you can do it with a waterjet. ;-)

Usually people use templates with their plasma cutter, and then cut the pieces out one at a time.

Richard

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Reply to
Richard Ferguson

Reply to
Michelle P

I think you could cut multiple pieces if you had your cut speed right on the gnat's ass but cutting patterns by hand I am sure would preclude this. Steve

Reply to
its me

They're only welded by the slag. This is pretty weak, so splitting them with a wide, fine chisel ought to be easy.

For multiple pieces with a plasma cutter you're usually best making one or more templates (thin wood or MDF) and doing them separately.

Reply to
Andy Dingley

The template idea is an excellent one and i plan to make one before my new Hypertherm600 arrives. Whopeeeeee

I had to run the old Miller Spectrum on high to cut thru the 4 pieces of 1/16" steel. Sometimes i went too fast and had to go back over the orig cuts. I did grind much of the edges but the 4 pieces are still melted together. Several places are loose. Havent tried the peanut grinder yet. Maybe the Hypertherm600 wld lightly burn that away...OW its a 1/4" thick Raven.

I cld just weld the edges and grind smooth and paint as is. Keep it for myself to remind me of my superior intelligence.. No paint wld be better for that..

Kinda like the glove i sliced thru with my band mill..Whew that was close..I pinned it up so I cld see it every day after that...

Tanks for help. Great site..

Reply to
bluedog

First of all, it is entirely possible to pull this off, but there are a few caveats:

1) 4 pieces is too many. I wouldn't go beyond three. 2) You'll need a plasma cutter with more power. The PowerMax 600 is a good machine and will be a good start. We have one at the shop and it will take limitless abuse. However, once you begin going through material thicker than about 1/4" you really have to s-l-o-w d-o-w-n. 3) Expect that if you stack three pieces, the edges on the top and bottom will be rough and the one in the center should be very clean. 4) This assumes you are moving at the right speed. Too fast and you won't cut through all three sheets. Too slow and you'll be WELDING them as you go.

Finally, do NOT place spacers. That will worsen your problem.

John P.

Reply to
John P.

Actually, the gas pressure should have little or no effect. The gas, in this case compressed shop air, is only serving to cool the torch tip.

The way the machine operates is that it creates a ~45,000 degree arc which vaporizes the metal it comes in contact with. The air supply is simply keeping the torch tip cool or it would burn out instantly.

The reason you have to keep the torch tip in motion all the time is that once the arc has pierced the material, it is still searching for the nearest metal to keep the arc going. If you continue to hold it in one place, that arc starts moving to the side as the hole becomes larger and this causes that 45,000 degree plasma stream to begin to come sideways out of the torch tip. This will burn up the tip almost instantaneously by taking your original round hole and turning it into a nice sideways slit. There goes $10...

John P.

Reply to
John P.

It is actually possible that the cut speed was too slow and / or the torch lacked the power to pierce 4 layers completely causing the material to actually weld...

John P.

Reply to
John P.

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