Questions About Metal Thickness

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ctwo
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Re: Questions About Metal Thickness

Post by ctwo »

FWIW, I used my 110VAC HF dual mig (the old, long obsolete model that does both gas or flux core) to convert an old Chevy LUV truck into a trailer. I was able to weld 1/4" just fine. It was a heavy duty small trailer...
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Carm
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Re: Questions About Metal Thickness

Post by Carm »

Steve
Is it possible to post a dwg. of your intended weld joint?
If the material is basic carbon, chances are it can be done with the equipment and skills you have.
It's good to consider our work important and critical, and no one wants to hurt oneself or others.
Truly critical work requires a tested welder working to a tested procedure, usually with a third party verification, and the SSN of the weldor is recorded with the weld. Probably not your situation.

Couple of comments from reading the thread.
ALL welding processes can trap inclusions, MIG is no exception.

Uphill welding is no stronger than downhill if the unit size is the same. True, downhill cannot carry the volume of metal per pass that uphill can.
Uphill can produce coarse grain, metallurgically undesirable. The reason weaving is verboten on much work. Large HAZ. Downhill has a refined grain even though currents are much higher.

xx-18 style rod can be run downhill but it is not an amateur technique.

A home shop guy or owner can do whatever they want, but any employer I know that sees you welding a snowplow with TIG will deposit shoe leather uphill one's posterior. It's a waste of time and money.
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SteveHGraham
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Re: Questions About Metal Thickness

Post by SteveHGraham »

The joints I had in mind are part of the finger brake kit I linked to, so there are no drawings.
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Carm
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Re: Questions About Metal Thickness

Post by Carm »

Steve
I took a quick look at your link.
You won't have any problem with that, assuming some degree of proficiency w/your welder.
Old rule of thumb for 70Kpsi filler is .75 x minimum leg for fillets.
So you need a 3/8" fillet for 1/2" plate...assuming that is req'd. Might not be.
For your machine, one pass on joint center, one pass with the arc on the toe of the first, puddle edge about halfway up the first pass, and third pass centered on the top edge of the first.
Grind the metal clean (angle grinder) and light grind or brush off any deposits before welding over. For a small MIG welder, best to get rid of mill scale.
Plan your run so you don't have starts or craters in corners.

You could get an argon rich gas mix and spray arc if you're concerned about "penetration" but there's a very good chance you'll toast your gun.
A good way to tell you have enough heat, the crater should have an area lower than the base, or you get some undercut on the top leg of a fillet- one of the reasons many weldors use a slight flick to fill.
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SteveHGraham
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Re: Questions About Metal Thickness

Post by SteveHGraham »

Thanks for the help. The tank I have now is 75/25, I believe.
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warmstrong1955
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Re: Questions About Metal Thickness

Post by warmstrong1955 »

I know of no one running lo-hy, like 7018 or 8018, rods downhill.
Other than rookies trying to smooth out a mess.
Places I worked, you would be kicked in the posterior hard enough to land ya in a different time zone if you ran it downhill! :lol:

5P....different story, but I still don't run it downhill.

Bill
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Carm
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Re: Questions About Metal Thickness

Post by Carm »

"I know of no one running lo-hy, like 7018 or 8018, rods downhill."

Maybe you don't know any tankies. I learned it from a career CB&I welder.
Doubt he was a rookie, he was my Dad's age and other hands on the job were telling stories about him on a job in Saudi Arabia.
Don't forget 15's & 16's are also slow hydrotain.
No iron powder, easier than 18's.
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warmstrong1955
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Re: Questions About Metal Thickness

Post by warmstrong1955 »

My world is heavy equipment, and a lot of pipe in mills & refineries.
No tanks.
15's & 16's aren't 18's.
My world, you just don't run downhill. Lack of fusion. Run over your own slag.
Not the way to have a mucker bucket stay together.

Bill
Today's solutions are tomorrow's problems.
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SteveHGraham
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Re: Questions About Metal Thickness

Post by SteveHGraham »

I need subtitles.
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warmstrong1955
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Re: Questions About Metal Thickness

Post by warmstrong1955 »

SteveHGraham wrote:I need subtitles.
No....you need to start welding!

;)
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SteveHGraham
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Re: Questions About Metal Thickness

Post by SteveHGraham »

Will I need hydrotain for my tankies or just 18's?
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warmstrong1955
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Re: Questions About Metal Thickness

Post by warmstrong1955 »

SteveHGraham wrote:Will I need hydrotain for my tankies or just 18's?
No worries....we got off on a tangent for sure. Sorry 'bout that.
However....I suggest...you stay clear of the tankies.
The one's I've been around....all the construction for thickners & leach tanks, we contracted out to tankies...they party hardy all night, and climb in the tank and sniff up the smoke durin' the day......makes 'em a bit.....off.... :wink: Just my experience.....
Did good work, but not quite normal.....but who is??

:)
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