How To TIG Weld Steel Corner and Lap joints

How To Tig Weld Corner joints and lap joints on steel.

Since last weeks video was building a stand for a Porter Cable Portaband, I thought maybe I would show how to tig weld end caps and feet on the stand.

I cut the end caps using the same portaband saw I was building a stand for.

Using a cheap dial caliper, I measured the inside diameter of the square tubing and added about .100" so that there would be some overlap. I cut all the end caps out of cold rolled 11 gauge sheet.

I like to tig weld outside corner joints. They are easy fun and sometimes do not even need any filler metal.

For this job, I used a little "trick" welding magnet tool called a MagTab.

Its made by Stronghand tools and you can get it from, Northern tool, Summit Racing, Airgas, and a bunch of other places.

I just checked on the price and while it was only about 10 dollars a year ago, The price of magnets has been rising so I think it costs about 13 dollars now.

It is a small but innovative welding magnet that utilizes a V- pad swivel along with an adjustable tab holder to create one of the handiest little welding tools to come along in some time.

The MagTabs primary use is to hold small tabs on round tubing while tack welds are made. The old way of hold tabs, and way I have done it for years is to hold the tabs with your fingers.

Holding small parts for tack welding is much safer with the MagTab. But what I did not anticipate is that it saves time too.

Usually, when something is safer, that translates to "less useful" "cumbersome" "time consuming", etc.

Not so with this little nugget.

Today, I found another use for it other than hold tabs... Holding end caps in place on square tubing.

I will be honest with you. I used to just hold them in place with a finger while I tacked. Its easy to get complacent after years of welding.

A few weeks ago, I was doing this, and the arc jumped right through my glove and gave me a deep burn on a finger tip and it hurt like a bear. Like worse than stubbing your little toe on the bed leg at 2am.

While the burns have long since healed, the memory is fresh enough that I actually turned around and drove back home on my way to the shop, after realizing I forgot my MagTab in my garage.

So back to todays video...

There are 5 different types of weld joints. ( this is a common question on written welding tests)

1. Corner Joint

2. Lap joint

3. Edge joint

4. Butt Joint

5. Tee Joint

Luckily, The first letter of each actually makes a word.


That is how I remember the 5 types of weld joints.

Corner joints are very common and are often welded from the outside and then are called "outside corner joints".

Lap joints are a very common weld joint too.

In this video, along with some tips on tack welding and the Magtab thingy, I show some tips for how to tig weld outside corners, and laps.

I know I have written about tack welding like a laser before, but it does work very well.

Here is a review.

Using a torch switch and with the machine set to 2t, and with zero upslope and zero downslope, I set the amperage to roughly twice what it takes to weld the joint.

then, using a sharp electrode, I position the tip of the tungsten electrode within about one electrode diameter from where I want the tack.

Then I press the torch switch for about half a second or less.

A caution.... try this on scrap metal first to get used to it. or you might blow some holes.

Once the end caps were tacked, I tig welded them all using several different tig welding techniques.

some with no filler metal

some using 309 ss filler metal

some using small circles

I used as low as 80 amps, and as much as 130 amps to weld the end caps and feet.

With a simple torch switch, and no amperage control, you can still make some adjustments by just traveling faster or slower.

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