DIY plasma cutter

Oct 27, 2013 8 Replies

HI all,



My new hobby involves making things out of RSJs. Trouble is, some of the stock I've acquired is damn big and thick and really too much for a junior hacksaw. So I'm forced to consider an alternative....



Do you reckon it's possible to make a plasma cutter based on an old welding transformer? AIUI, the mechanism of action of plasma cutters is similar to the act of arc welding, but blowing out the molten metal as opposed to augmenting it with a filler rod. I think the tricky bit is finding a suitable electrode to take the place of the filler rod. It would need to be hollow, so you can blow air through it. It would need to be metal of some sort, as it will need to be conductive so you can strike up an arc. How could one prevent it from sticking to the work to be cut (given there will be no flux coating) and from eroding away too quickly to avoid constant replacement? Any ideas?



cheers, CD


Thermic lances are quite straight-forward.

You can buy cutting rods for a "stick welder" ie old fashioned electric welding transformer. They need significant current I seem to remember. They look just like a coated welding rod but they cut instead of weld.

Wrong again.

Tescos only stock weetabix.

Well, well, well. Seems you're right, H. Cheers for the info!

You're just showing yourself up to be ignorant when compared to harry, and that is going some.

Here's some as an example:

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Most reviews would suggest that it's not a pleasant experience. And I have seen articles where a standard stick has been used to burn through, something I have no trouble doing when trying to weld!

They are pretty messy to use (they might have improved since I used them) ie leave a very rough cut

You will need your angle grinder aftrwards!

whoosh!

I didnt expect you to fall into the gibbon trap. or miss teh irony.

Harrys standard response is to say wrong, and then cite a totally unrelated fact as evidence of why it is wrong.

I am not ignorant, but I am apparently too subtle for you :-(

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