TIG practice and a question

[pgerhardt]

I got a chance to practice TIG welding today. I thought I would practice all the types of repairs needed on my fender on scrap sheet metal first. The first challenge was filling extra holes drilled in the fender. (picture 1)

So I drilled holes is a piece of scrap sheet metal. (picture 2)

Now they are all gone! (picture 3)

I’d like to say they were the same three holes, but the are not. It took about 20 holes before I got the right amperage and technique to fill the holes in picture 3!

BTW I am finding I like to finger control better than the petal since with the finger control I know I am getting the amperage I set. I tend to have a lead foot on the petal control! I think there are petals where you can set the max amps right on the petal. I've got to get one of those and of course get lots more practice.

While practice is good, I do miss not being to ask someone what not to do when I screw up. Todays question: What causes, and how to avoid cratering?

Thanks in advance for any replies.

[1930artdeco]

Pgerhardt,

Looks good to me but then again I am just starting to learn in my basic class. You may try this forum out http://weldingweb.com or the garage journal has a fab section as well.

Mike

[Dollar Bill]

Crater caused by too much heat or not enuff filler rod or combination of both.

[Pete]

One way to weld up small holes like you have is to lay the filler rod across the hole as you start, then weld right over the rod as you go. It helps to keep from burning the hole out larger.
Start with the heat control on minimum and bring it up slow.
If you have high frequency start, that helps also.
You don't need a special pedal control. Set the maximum current on the welder, then full down on the pedal will be that ammount.

[v bogart]

It has been a few years 15+ that I have touched a tig ,But as I remember The longer You stay in one area You will burn all the cylica(sp) out and make the pitting Practice practice and more practice. The faster you can weld it up the better it will look. Hang in there

[choptop30]

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What type welder did you buy? I just purchased the new model tig welder from Harbor Freight this weekend and need to wire up a 220 plug in the garage to try it out. I purchased it for the foot control so I could attempt to weld the body metal with less distortion.

[Mike V. Florida]

Originally Posted by choptop30

What type welder did you buy? I just purchased the new model tig welder from Harbor Freight this weekend and need to wire up a 220 plug in the garage to try it out. I purchased it for the foot control so I could attempt to weld the body metal with less distortion.

He bought an Everelast 160 STH. It is DC only (Not much aluminum in a model A!) but has great reviews and high frequency start.

[noboD]

Try SS, it is easier to learn on. You can control your heat with the filler too, more filler will cool the weld.

[Terry, NJ]

As Pete said, laying the rod across the hole to start. I go a step further. Having plenty of old 1/8" Stick wire as a source, I break the flux off and stick it in or lay it across the hole. Another method of hole filling, with larger holes. I use the "knock outs" from old electrical boxes, when the holes are close in size.
Terry

[Rex_A_Lott]

Its good that you are using the finger control, its kind of hard to work that foot pedal when you're laying on your back under the car.
Pete was right about the max current being on the machine itself for the foot pedal, set it low and push away. If you arent doing it already, its much easier to get used to the pedal if you're sitting down. Get yourself a stool and try it. Not having to jiggle your own weight back and forth on your feet takes some of that heavy-foot away.
The cratering at the end of the weld is causing by jerking the current away too fast. Try easing up on the control, and/or increasing the travelling speed so much that the bead size tapers down to nothing as you pull the torch away gradually until the arc goes out. If its porosity all along the weld you are referring to, its caused by contamination, whether from the base metal itself or from the oxygen in the air around the weld. Cleanliness is your friend. As mentioned, a stainless filler rod will sometimes get rid of this.
Good Luck!

[texas webb]

Also back up your weld area with a piece of copper.

[Ron W]

Craters can be caused by contaminants and/or not enough argon. Use at least 15 cfph on steel. Holes 1/4 in or larger should be plugged first with metal the same thickness and then welded. That reduces the amount of weld and heat necessary to close the hole. If you must weld the hole in, you can use methods suggested above or clamp a piece of steel behind the hole, fill to level, then grind off the excess behind. steel welds can also be backed up with aluminum or copper. Use a 1/16 in electrode for sheet metal and don't let it touch the work. If it does, resharpen to a pencil point immediately. Have fun! Ron W

I was slow typing. Also stop the arc and let the gas continue a few seconds before lifting the torch to shield the area till it cools some.

[Ron W]

Ron Covell has 2 great videos here; http://covell.biz/dvds
Ron W

[pgerhardt]

Originally Posted by choptop30

What type welder did you buy? I just purchased the new model tig welder from Harbor Freight this weekend and need to wire up a 220 plug in the garage to try it out. I purchased it for the foot control so I could attempt to weld the body metal with less distortion.

An Everlast 160 STH. It is DC only but come with finger switch and petal controls, has High frequency start, and has great reviews. I had enough points earned on my Amazon credit card to get it so it was the choice for me!

[pgerhardt]

Thanks everyone for the tips and feed back, This is the kind of info I needed!

[d.j. moordigian]

Originally Posted by pgerhardt

I got a chance to practice TIG welding today. I thought I would practice all the types of repairs needed on my fender on scrap sheet metal first. The first challenge was filling extra holes drilled in the fender. (picture 1)

So I drilled holes is a piece of scrap sheet metal. (picture 2)

Now they are all gone! (picture 3)

I’d like to say they were the same three holes, but the are not. It took about 20 holes before I got the right amperage and technique to fill the holes in picture 3!

BTW I am finding I like to finger control better than the petal since with the finger control I know I am getting the amperage I set. I tend to have a lead foot on the petal control! I think there are petals where you can set the max amps right on the petal. I've got to get one of those and of course get lots more practice.

While practice is good, I do miss not being to ask someone what not to do when I screw up. Todays question: What causes, and how to avoid cratering?

Thanks in advance for any replies.

I do a lot of TIG welding,..most every day and I do aircraft parts also. Your
welds in the second photo looks way too hot! I have a few suggestions..

1. Use a 1/16" tungsten,..it will start easier! I have .045" tungsten for the
very light material that I weld,...down too .015" Aluminum and SS.
2. The filler rod diameter I use for light stuff if 1/16" or 1/32",...it drops off
the rod much easier than the bigger rod.
3. IF the hole is 3/8" or larger, I make a plug, and weld it in! Less shrinkage
of the parent metal..

[1Tudoor]

Originally Posted by choptop30

What type welder did you buy? I just purchased the new model tig welder from Harbor Freight this weekend and need to wire up a 220 plug in the garage to try it out. I purchased it for the foot control so I could attempt to weld the body metal with less distortion.

I read the HF feedback on this & it is just for steel & saw a couple of U tube videos which were so so .
Curious how you make out w/ it --pls post .

[pgerhardt]

Originally Posted by d.j. moordigian

I do a lot of TIG welding,..most every day and I do aircraft parts also. Your
welds in the second photo looks way too hot! I have a few suggestions..

1. Use a 1/16" tungsten,..it will start easier! I have .045" tungsten for the
very light material that I weld,...down too .015" Aluminum and SS.
2. The filler rod diameter I use for light stuff if 1/16" or 1/32",...it drops off
the rod much easier than the bigger rod.
3. IF the hole is 3/8" or larger, I make a plug, and weld it in! Less shrinkage
of the parent metal..

Yes I had 3/32 tungsten and 3/32 filler rod. Both were too big, and with my lead foot I was using too many amps, but I now have a pack of 1/16 tungsten and 1/16 filler rods. I'll practice, practice, practice, but there there is nothing better than in person instruction. I'll have to see if there is a good welder in my car club who would not mind me looking (with helmet!) over their shoulder and asking questions.

One thing is becoming clear to me. Unlike stick and MIG, TIG welding is quite a delicate and precise process!

[d.j. moordigian]

Originally Posted by forever4

I like to use 0.040 tungsten and 0.035 MIG wire when working on sheet steel.

Vince,...You made me go look in the draw,...it is .040"! Thank you..
I just know its in a zip-lock bag so it doesn't get mixed with the 1/16" stuff.

I also use the MIG wire,...BUT the Aluminum wire, and I think it's .025", the
Steel and the SS wire I get in the "box" so I don't have to straighten it...

You know it's an "age thing",..and I'm wore out!

Dudley

[BILL WILLIAMSON]

Originally Posted by d.j. moordigian

Vince,...You made me go look in the draw,...it is .040"! Thank you..
I just know its in a zip-lock bag so it doesn't get mixed with the 1/16" stuff.

I also use the MIG wire,...BUT the Aluminum wire, and I think it's .025", the
Steel and the SS wire I get in the "box" so I don't have to straighten it...

You know it's an "age thing",..and I'm wore out!

Dudley

Just wait 'til you're 80, Sonny Boy
Willy Bill Old