Copper shot?

Chop copper bar into short cylinders. If they need to be more rounded put them in a tumbler (the rotating sort not the drinking sort :) )

Andrew

He is using 'BBs'- which you can get here- they are used in BB guns, similar to air guns.

BB guns are more popular in the US but you can by them here, along with the pellets. I always assumed the pellets were plastic but perhaps you can get copper ones.

While 'killing time' when my wife was looking at shoes on a recent holiday in Devon/Cornwall, I stumbled across a shop with an impressive array of BB guns in the window. They looked remarkably like real guns.

Usually copper plated steel not solid copper, why would you go to the expense. They're available on ebay in the UK. The only place I found in Europe with a quick search was

You may well be correct, I was going by the fact the video used them and referred to them as copper.

Well on both the video and the page he mentions using BBs for the concept trial but thinks that another material such as copper or SS balls may be better to reduce contamination potential with some materials. Neat idea anyway I have a few back purge rigs for TIG but that seems like a nice one to keep in mind for the future.

The purpose seems to be to make the gas to 'spread out' and I doubt the exact shape is critical. The idea someone else had of use bits of copper rod would probably be fine or some inert 'pebbles'- perhaps even the ones used in baking to keep flan cases flat.

Ouch! I didn't even ask the price ...

Thanks, but probably a bit too contaminating. Plus zinc fumes, ugh!

I have some aluminium oxide "pebbles", but pure(ish) copper would also provide the earth connection, and act as a heatsink.

-- Peter Fairbrother

I went to the link provided and he was using copper plated steel balls. He was concerned about contamination and arcing through the thin copper plating. If you want closer to pure copper you can get casting grain from various suppliers. Some casting grain has tiny amounts of other alloying ingredients to help with the casting process but you can get .999% pure stuff too. Ebay is one source. I bet Ali Express sells it too. And of course Otto Frei and Rio Grande both sell it. Eric

Just a thought:- If you can eliminate rust, e.g. put a lid over the box at the end of the job and purge a bit more, then steel balls might work just as well as copper ones. After all welding benches tend to be steel.

regards Mark Rand