A Trick for Tack Welding Stainless Steel Sheet metal
You Might want to Mute the Volume...he drops the "F-bomb" at the end
Tack Welding Stainless Steel
Here is a good trick for tack welding stainless steel and carbon steel.
Do it quick. Really quick.
The welder in this video has figured out that a really short pulse of current works a lot better for tack welding stainless than trying to sneak up on it....so he has his tig welding machine set to deliver probably between 1 and 1.5 amps per thousands of thickness and all at once.
But only for like a tenth of a second.
If you are going to try this you have to make sure there is no gap and you have to be really quick. Otherwise you will just melt the edges away.
You also need to hold a tight arc and be lined up on the exact area where you want the tack. That is why the welder does not even nod his helmet. That's not really considered "best practice" as far as welding safety is concerned but then again I am pretty sure he doesn't give a piss what I think.
Be sure to practice a little on some scrap before you try this because you can definitely melt some edges away if you are not careful. Some newer tig welders are even equipped with a tack weld setting just for doing this, but for older tig welding machines like the Miller Syncrowave 250 or 300, you can just set the amperage switch to panel instead of remote and by trial and error on scrap, you will figure out the amperage that will tack this quickly but not melt too much.
This little trick works best on stainless but it works pretty well on carbon steel also. Like I said , just make sure there is a tight fit-up and have your cross hairs on the exact place you want the tack.
One metal this does not work well on is aluminum. You pretty much need to use filler rod whenever you tack weld aluminum or it cracks nearly every time.
Now for a disclaimer...At the end of the video he drops the "F bomb". If that bothers you, or if the wife and kids are near, please Mute your speakers or turn your volume off. There is nothing to hear but music from his radio anyway. I almost didn't use this video because of the unnecessary F word but its a good tip to talk about.
Another thing to notice is how quickly he moves the torch on the fuse weld with no filler rod. He is hauling butt and outrunning the heat to avoid distortion, excessive oxidation, and just to get er done.