Thoughts on Welding

[GreenTwin]

While this furnace looks a bit rough around the edges, it is a fast-acting, highly functional iron-melting furnace, and the refractory (Mizzou) can withstand repeated iron melts with minimal degredation.

20 lbs of gray iron can be melted and poured in about an hour.

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[GreenTwin]

The furnace in action.
The area around the tuyere needs to be closed up a bit better.

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[GreenTwin]

Here is a welded steel Ursutz-type burner, which is a very bad way to build one of these burner types, because the steel deteriorates very quickly at red hot temperatures.
I used this burner once, and retired it.
This is a lesson in how NOT to build a burner.

But it is welded construction.
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[SmithDoor]

In a recent hijack of a new member introduction (New from Atlanta Ga), there seemed to be some energy / interest in discussing matters related to welding. As one of the hijackers, I thought I'd repent and start this thread to relocate that discussion.

One of the matters that has been raised is which rod people prefer to use, with several expressing a preference for 6013. There was also some discussion about drying rods. Here are my $.02 on the rods I tend to use:

6010 and 6011 use a cellulose-based flux that is not affected by moisture. I have seen at least one chart that recommends against drying these rods or storing them in a rod over. Following directions I read long ago, I have soaked either of these rods in water, then used them at very high amperage as cutting rods - pretty crude cutting, but effective. They are fast-freeze, deep penetration; they can be used on rusty metal.

6013 and 7014 use a "rutile" flux ... whatever that means. IIRC, it is not particularly sensitive to moisture - it can be stored without any particular precaution, but can also be dried / stored in a rod oven. These are low penetration rods; 7014 is higher deposition of metal due to iron content in the flux.

7018 is a low-hydrogen rod, and this is the one where dryness really, really matters. Moisture in the flux will mess up not only the welding characteristics but also the low-hydrogen characteristic. Low-hydrogen is particularly important for higher-carbon steel. Should be stored in a rod oven.

Of these, 6010 is DC+ only, but the others can be run DC+ or AC. I think 6013 and 7018 can be run DC- as well; I'm not sure what the advantages or disadvantages would be.
Of these, 6010 and 7018 require a higher open-circuit voltage, which may make them hard to start when using lower power welding machines.

All of the above is based on fuzzy memory and a brief skimming of some reference materials, so I welcome corrections, alternate experiences, etc.

Best way is the rod you like.
E7018 is a good rod but it needs per heating to about 350°F and in some case the part may need per heating.
It mainly use if part is Xray.

Most probably do better with fluxcore E70T-G or E71T-11. Takes less power for a small shop. The 120volt welders like flipping the breaker a lot so just use 240 volt size and you will be happy.

Dave

 

[Steamchick]

Hi GreenTwin. re post: #15.
Thanks for all that information - really good stuff (as usual).
I am sure you are pretty good with your safety practices. But here's what I was taught, for the sake of other less experienced readers who may follow what you are doing in this or other ways.
You mentioned this regarding working on "old fuel tanks":
"It is not safe to reweld once you have had fuel in it, so test it with compressed air first."
So: Once it has had fuel in it....
Fuel tanks - such as on motorcycles - often have "poor" interiors. say a bit of rusting, or seams, or joints that can trap some fuel that doesn't obviously escape with a compressed air blow-through. So I was taught (with 40 gallon drums that were a bit second-hand, but were going to be adapted and have some stuff welded on).

• Fill the tank with WATER - and a squirt of detergent, like washing-up liquid, hand soap etc.
• Drain the water, sloshing the stuff around on the way to wash everything (and wash-off loose detritus, rust, etc.
• Re-fill - again with WATER and a bit of detergent.
• Build a fire underneath. On the 40 gallon drums, they were raised on bricks first and a wood fire built beneath. One had contained old engine oil, the other diesel fuel.
• Bring to the boil.
• The detergent will not only clean the inside, but the boiling will create foam that traps and inhibits fire from any evaporating fuel or oil vapour. Any space above the water level will be filled with steam to vaporise fuel, etc. and displace it from the tank, so it blows away safely in the air.
• Allow to cool and drain (we opened the tap at the bottom).
• After draining, gently heat - on the residue of the fire, with some compressed air blowing through - just a wee draught is adequate. You can test the air coming out with a good nose for fuel-ish smells. Should be none. When dry, you can attack the tank with an angle grinder (lots of ignition sparks!) or welder (even more ignition sparks!) safely, as you will have driven off the hydrocarbons and avoided an explosion.
• I also did this before attacking a leaking motorcycle fuel tank. All I had was a camping stove, water and hand soap, but it worked just as well.

Takes a bit of time, but what is time when you are ensuring it won't explode when you are working on it...
Also "It is not safe to reweld once you have had fuel in it, so test it with compressed air first." - JUST testing with compressed air is not safe unless the job is good - which you don't know until tested. = "CATCH 22"!
Also, from boiler experience (I have never blown-up a boiler, but have seen pictures), I would always hydraulically test before an air test.
Air contains a huge amount of energy. Use a foot pump instead of a big compressor and you'll appreciate how much! That energy expands explosively if there is a failure. With an hydraulic test, there is a little "ding" noise and water drains onto your foot - at worst you get a wet foot. Curiously, (PLEASE correct me if I am wrong?) I understand that water molecules (H2O) are smaller than "air" (N2 or O2), so water will find a smaller leak that air... (In industry we used Helium, as the smallest, safe, molecule. Hydrogen is the only smaller molecule, but extremely explosive!). Water is quite easily detectable if you dust the surface with talc, cement, plaster, or another fine dry powder, as you can easily see the damp spreading from a tiny pin hole before you detect any pressure drop or drips.
You can use a low pressure of air - (say 5 psi?) - and test with soapy water for leaks, but more than that if a large tank (anything bigger than a large coke bottle!) has a fitting that lets go can cause damage to hearing. You cannot see the air-pressure shock wave, but I have tinnitus from "loud bang" testing in the 1980s. My Mother was 90% deaf from loud bangs from air raids (near misses) in WW2. (Better than being blown-up though).
Take care. I didn't, and my body "bears the hidden scars of experience" (Tinnitus, Arthuritus, stupidity, etc...).
K2

 

[ajoeiam]

Sometimes when I weld heavier pieces, and I turn the amps up, the rod will overheat before I get through the entire rod.
I am using a standard size rod, which I guess is 1/8"? (I will have to check that too).

So to avoid overheating the rod on high amperage welds, do I need a thicker rod, or what?

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Hmmmmmmm - - - - afaik there is no such thing as a 'standard' size rod.
There are common rod sizes but then you might run into something that was custom produced (like a 17/64" 7024).
(When you're buying rods by the ton, or megagram, options start showing up - - - grin!)
Sizes I've run into: 1/16, 3/32, 1/8, 5/32, 3/16 and 1/4" (1.6, 2.4, 3.2, 4.0, 5.0 and can't remember what the mm size was on the 1/4" boxes) . Have run into bigger for hard surfacing and have heard of larger used in heavy industry (welding floor plates into rock trucks) but there's no way I know everything that's available. Then there's the rods for specialty materials - - - really dunno even many of the options - - - grin - - - its not a small field!
1/8" is very easy to get.
If the rod is over heating, i.e. its melting through above the puddle, then I'd suggest you're running too much heat - - you don't really need that much.

 

[Steamchick]

Each rod diameter has a different nominal current. To make a fillet weld 30mm x 30mm the ENGINEER specified a 5mm root run, then many 6mm rod fillers to full size. Because of the required change of current from 5mm rod to 6mm rod we did some samples using a 6mm rod root-run and, after approval, all the welds were done with only the 6mm rods. The continual need for current change would cost a lot of money! Nearly 4000 welds! We had to use double cables to avoid the cables from cooking.
K2

 

[GreenTwin]

I can remember my dad doing welding tests, and he used two steel bars, perhaps 3/8" thick, 2" wide, 4" long each.

He would gap and clamp the pieces, weld them from the top only, grind off the top and bottom smooth, and then use a sledge hammer to bend them 180 degrees back on themselves.

He would do this from the front, and with another piece from the back.

There was never any cracking or weld failure.

The intent as I understand it is to make a weld that is stronger than the surrounding material, with uniform continuity all the way through the joint.

He also said it was a demonstration of getting full weld penetration from one side only.

I recall trying to weld something one day (in my early welding days as a teen 47 years ago), and the welder in dad's shop had long leads, like 100 feet long.
I would start welding, and dad and his buddy co-worker would turn off the welder.
My rod would get stuck, and I would have to twist it off, and then would try to strike the arc again.
I would raise up my welding helmet as I was trying to start welding, saying "what the flock is going on ?".
Then dad would turn the welder back on, and I would get a huge arc flash in the face.
I finally figured out why those two characters were hovering around the distant welder.
LOL, good fun those days.
Dad knew how to have fun.
My eyes are almost healed, but I can still see a few spots.

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[ajoeiam]

Each rod diameter has a different nominal current. To make a fillet weld 30mm x 30mm the ENGINEER specified a 5mm root run, then many 6mm rod fillers to full size. Because of the required change of current from 5mm rod to 6mm rod we did some samples using a 6mm rod root-run and, after approval, all the welds were done with only the 6mm rods. The continual need for current change would cost a lot of money! Nearly 4000 welds! We had to use double cables to avoid the cables from cooking.
K2

Hmmmmmmmm - - - interesting - - - what kind of settings were you using?
And what size cables?

(Curious - - - you know - - curious george here!) (Dunno how many here will remember or connect on this allusion - - - grin!)

 

[ajoeiam]

snip

I recall trying to weld something one day (in my early welding days as a teen 47 years ago), and the welder in dad's shop had long leads, like 100 feet long.
I would start welding, and dad and his buddy co-worker would turn off the welder.
My rod would get stuck, and I would have to twist it off, and then would try to strike the arc again.
I would raise up my welding helmet as I was trying to start welding, saying "what the flock is going on ?".
Then dad would turn the welder back on, and I would get a huge arc flash in the face.
I finally figured out why those two characters were hovering around the distant welder.
LOL, good fun those days.
Dad knew how to have fun.
My eyes are almost healed, but I can still see a few spots.

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Somehow - - - - I don't think what they did was actually 'funny' - - - especially if you've had vision spots ever since.

(apologies to those that think this kind of think 'is' fun but horseplay that results in any kind of injury (like actual injury not that of the ego) is no longer
horseplay - - - - its violence (and I love a great practical joke but the goal is to make sure there are no 'negative' benefits!!).)

 

[GreenTwin]

No permanent eye damage luckily.
I am not into pranks around equipment and such, but sometimes dad was.
It was a good prank for sure.

Sometimes I look back on my youth and wonder how I survived.

We played with mercury out of light switches, and also played with the sheet of asbestos that was stored in the shop (don't ask me why, we just did dumb stuff).

Those were the days for sure when dad was around.
Never a dull moment.

Edit:
We ran with scissors, and basically always did the opposite of what our mom told us to "never do".
That is what kids did.
We did not have smart phones, and so we did all sorts of crazy stuff for entertainment.

I recall the kid next door discovering the entrance to a storm drain, and so we spent hours exploring that underground system around the neighborhood.
It was a pipe large enough to stand up in.
It just happened not to rain when we were in there.
And we built forts in their too.
We probably singlehandedly created the need for OSHA.

Edit2:
My mother said "Whatever you do, don't go near those railroad tracks that are a few blocks from our house".
So what do you think we did every afternoon? We would go put pennies on the track, and wait for a train to run over them.

Or she said "Don't go near that construction site" (they were building an expressway nearby back in the day when they were building a lot of those).
So we had the greatest time playing on that huge site that was many miles long, and full of incredibly dangerous stuff.
Boy was that fun.
We had a huge earthmover almost run over us one day.

It was just assumed when we were growing up that if you did something, you did it safely, and if you did something you were not suppose to do, then you just kept quiet about it, and all was good.

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[GreenTwin]

These are the rods that I use.

I will have to measure the diameter I use, since I don't see that marked on the box.
I am assuming I have 1/8" rods.

I have not paid too much attention to the exact rod type in the past, but as the package says, these rods work well in all positions, have deep penetration with low splatter, and work well even if the metal has mill slag/rust/oil on it.

Great rods.
I have very found a better rod.

And from the chart on the box, the larger the rod diameter, the higher current it can withstand.

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[GreenTwin]

This is the tombstone Lincoln I use.
These use to go for around $100.00.
Inflation has gotten bad these days.

 

[GreenTwin]

This is the tombstone Lincoln I have always wanted, but they were always more than double the cost of an AC-only unit, and so I could never justify the cost.

The AC unit I use works well, and so I can fix what is not broken.

My dad had a nice large commercial old Lincoln AC/DC unit, and that thing would put out a ton of amperage continuously, and was an extremely smooth welder.

 

[GreenTwin]

The amp rating on the tombstone Lincolns is a bit deceiving I think.
It is not a continuous rating.

I have never had an issue with my Lincoln overheating or anything, so I guess the actual demand is pretty low.

I saw one guy put a huge fan on the side of his welder, and he was able to get a much higher continuous rating out of his unit.

They do that with power distribution transformers, ie: for the same unit, if you add fans, you can get a significantly higher rating.

I found a somewhat reasonably priced AC/DC tombstone Lincoln on ebay, but 12 hr drive one way, so no cost savings there.

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[RM-MN]

I have a Century AC/DC welder. The day after I got it, I switched it to DC and have never switched it back. A few years ago I was intrigued by the cheap inverter welders, DC only, 200 amp max. The Century welder has not been switched on since. The inverter welder is so light weight that I can easily move it to the job instead of trying to move the job to the welder. I even made up an extension cord for it to give me even greater mobility. It is a little harder to start an arc than my Century welder but is welds smooth and I have not been able to exceed its duty cycle. This is one like the one I have but different brand.

https://www.ebay.com/itm/2844894451...fuAbe8cNF9jSoYewqlPh3E8Sw=|tkp:Bk9SR9CclbrYYg

 

[GreenTwin]

HITBOX ARC Welder 110/220V 200A DC IGBT Inverter Rod Stick ARC Welding Machine​

I guess I have not kept up with welder technology.

This seems pretty wild what it does for its size and weight.

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[Steamchick]

Ajoeiam. I can't remember the welding current, but cables are rated for Intermittent useage, but the welding we were doing was more than the expected cable rating of 30% or 50% duty cycle. It was "Cooking hot" around the weld. The slag peeled off very cleanly, so a quick wire brush and he could weld another pass to build-up the required section. Maybe something like 80% welding 20% brushing/changing rod? Something like 15 to 20 rods to build-up the weld section required to carry the current from the Aluminium Smelter tanks. (120,000Amps DC at 80volts from the power station).

 

[ajoeiam]

Ajoeiam. I can't remember the welding current, but cables are rated for Intermittent useage, but the welding we were doing was more than the expected cable rating of 30% or 50% duty cycle. It was "Cooking hot" around the weld. The slag peeled off very cleanly, so a quick wire brush and he could weld another pass to build-up the required section. Maybe something like 80% welding 20% brushing/changing rod? Something like 15 to 20 rods to build-up the weld section required to carry the current from the Aluminium Smelter tanks. (120,000Amps DC at 80volts from the power station).

Hmmmmmmmmmm - - - that's real interesting. I had never heard of cables having a duty cycle rating.
Power sources - - - you bet - - - cables - - - 'never'.
Don't see anything like that in the electrical code either - - - at least not in the 3 versions I have parked here.
(When you're working outside and its in the colder than -30C (circa -20F) range and you can grab your cables to warm your hands you know that you're running some juice.)

 

[GreenTwin]

In the electrical design world, the rating of any given wire or cable depends on where you put it.
Cables suspended in free air have a much higher rating than the same cables installed in conduits.
Cables in ductbanks have to be derated depending on how many cables are around the.
Wiring installed on high ambient conditions are derated per a chart.

I had to install an exhaust fan on one large temporary feeder that was on the roof.

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