Handheld welder

[TJM]

Most metals melt (weld) in excess of 2500° F That would melt right thru a hull

 

[KnotYet]

Most metals melt (weld) in excess of 2500° F That would melt right thru a hull

I confess to welding on my boat in the slip. I kept a water hose spraying on the
outside of the steel hull to keep the paint from smoking and catching fire...

 

[paulga]

No, it’s likely about the huge amount of current potential going to ground.

The current can only go to the ground via the ground wire. But should there be any current in the ground wire? The current exists between the pair of hots

 

[Delta Riverat]

I think it has more to do with fires, fumes and red hot balls of flying steel than ground currents.

My marina has a "no grinding" policy also. Because hot metal dust will embed into gelcoat and mess up your neighbor's boat.

 

[Bmarler]

The current can only go to the ground via the ground wire. But should there be any current in the ground wire? The current exists between the pair of hots

Depends on the welder. Many are dc. Depending on the process, polarity is either electrode positive or negative, which changes the current path. A welding ground clamp can have a poor connection resulting in current finding a path through the neutral or ground wire, not to mention, inductive possibilities. I’m not saying it can’t be done safely, but most places would just rather not take any chance.
And , as has been mentioned, fire risk.

 

[paulga]

Depends on the welder. Many are dc. Depending on the process, polarity is either electrode positive or negative, which changes the current path. A welding ground clamp can have a poor connection resulting in current finding a path through the neutral or ground wire, not to mention, inductive possibilities. I’m not saying it can’t be done safely, but most places would just rather not take any chance.
And , as has been mentioned, fire risk.

if NEMA 10's neutral lead has the grounding wires connected on both the feed and equipment side, ie. the neutral lead works as the gnd as well, in practice, does NEMA 10 function exactly the same as NEMA 14?

 

[Bmarler]

if NEMA 10's neutral lead has the grounding wires connected on both the feed and equipment side, ie. the neutral lead works as the gnd as well, in practice, does NEMA 10 function exactly the same as NEMA 14?

In practice, yes. The reason nema 14 came to use was the separate grounding wire.
In a nema 10, where the appliance was indirectly grounded by the frame to the neutral, it also relied on the neutral to ground connection at the panel. If something happened to compromise the neutral, dangerous voltage could be transferred to the appliance frame.
Nema10 was phased out in the mid 1990’s, but remains “grandfathered” in as there were so many installations using it.

 

[paulga]

In practice, yes. The reason nema 14 came to use was the separate grounding wire.
In a nema 10, where the appliance was indirectly grounded by the frame to the neutral, it also relied on the neutral to ground connection at the panel. If something happened to compromise the neutral, dangerous voltage could be transferred to the appliance frame.
Nema10 was phased out in the mid 1990’s, but remains “grandfathered” in as there were so many installations using it.

Thanks.
in case of a ground fault, does the fault current flow through the ground wire to the panel, then follow the neutral wire back to the transformer? i always thought it flows to the earth via the ground rod connected to the panel.

Ground, Neutral & Hot Explained

Ground, Neutral & Hot Explained, FREE COURSE learn what each wire is for in an electrical system as well as the ground rod, GFCI and ground faults.

theengineeringmindset.com

 

[Bmarler]

ground fault follows the path of least resistance on it's way back to the source. the ground rod at the panel will have higher resistance than traveling back to the ground rod at the source.

 

[paulga]

ground fault follows the path of least resistance on it's way back to the source. the ground rod at the panel will have higher resistance than traveling back to the ground rod at the source.

the source is the transformer, right?
i had similar questions previously but didn't think it through
in the drawing in post 38, the fault current has two paths, like that article said, the path of ground-neutral with lower impedance, and the earth with high impedance. why do the two paths not form a "parallel circuit" where the fault current flows through both branches?

a related question i guess is, the gnd wire could still shock a person if there is fault surge flowing through, why is the neutral wire arguably safe to touch when there is current flowing through continuously?

 

[Delta Riverat]

Ground is always ground. Neutral is connected to ground at the box. In a parallel circuit current will flow in both branches, lower impedance gets higher current, but current will flow in both sides.

 

[paulga]

Ground is always ground. Neutral is connected to ground at the box. In a parallel circuit current will flow in both branches, lower impedance gets higher current, but current will flow in both sides.

Thanks.
so it's not a parallel circuit. when the metal casing is grounded, it is at the same potential as the ground/neutral, and the person that touches the casing. the current does not come to the person just like it does not shock a bird sitting on a bare line.

 

[Bmarler]

the source is the transformer, right?
i had similar questions previously but didn't think it through
in the drawing in post 38, the fault current has two paths, like that article said, the path of ground-neutral with lower impedance, and the earth with high impedance. why do the two paths not form a "parallel circuit" where the fault current flows through both branches?

a related question i guess is, the gnd wire could still shock a person if there is fault surge flowing through, why is the neutral wire arguably safe to touch when there is current flowing through continuously?

Yes, transformer is the source. It’s almost a parallel path, but only in relation to ground, not in relation to the source. There would be a minute amount of current on the path to ground from the panel, but almost not measurable. The bulk would be going to the source. The reason you can touch the neutral wire is that it’s at the same potential as ground. Connected at the source.

 

[paulga]

Yes, transformer is the source. It’s almost a parallel path, but only in relation to ground, not in relation to the source. There would be a minute amount of current on the path to ground from the panel, but almost not measurable. The bulk would be going to the source. The reason you can touch the neutral wire is that it’s at the same potential as ground. Connected at the source.

Parallel circuits have equal voltage in all paths. In the drawing in post 38, if a person touches the metal base that suddenly contacts the hot wire, the person becomes a new path added. But if there is going to be the same voltage on the person, that would defeat the purpose of having the ground wire.

 

[Bmarler]

Parallel circuits have equal voltage in all paths. In the drawing in post 38, if a person touches the metal base that suddenly contacts the hot wire, the person becomes a new path added. But if there is going to be the same voltage on the person, that would defeat the purpose of having the ground wire.

I feel like we’re getting into the weeds with this discussion. To the average person reading this forum, we should concentrate on following best practice, and leave the electrical theory to other venues.

 

[paulga]

i like the little miller maxstar. tig and stick. nice little welder. there are other similar ones out there for cheaper though, so look around.
i haven't used this little machine from everlast, but my son has a couple of their products that he really likes. he's a very talented stainless fabricator.

Amazon.com

the good machine is bulky and heavy, it requires a dedicated circuit, a gas tank and ventilation device. it's in the same category of an air compressor, designed for a shop rather than an amateur who does not do it routinely.

if the inrush amp is 28 and effective amp is 17 in 110v, how to size the circuit breaker or fuse?

 

[Bmarler]

the good machine is bulky and heavy, it requires a dedicated circuit, a gas tank and ventilation device. it's in the same category of an air compressor, designed for a shop rather than an amateur who does not do it routinely.

if the inrush amp is 28 and effective amp is 17 in 110v, how to size the circuit breaker or fuse?

View attachment 160347

A 20 amp breaker should be ok. If it can’t handle the inrush current, you can look for a different trip curve breaker.
Also remember, that’s max, not what you’d likely be running at.

 

[paulga]

i like the little miller maxstar. tig and stick. nice little welder. there are other similar ones out there for cheaper though, so look around.
i haven't used this little machine from everlast, but my son has a couple of their products that he really likes. he's a very talented stainless fabricator.

Amazon.com

could you recommend a small welder that can weld alum plates, like this hoist system mount?

 

[Bmarler]

could you recommend a small welder that can weld alum plates, like this hoist system mount?

View attachment 160540

There isn’t really a small welder capable of welding aluminum plate. Aluminum takes a ton of amps to weld properly as it dissipates the heat so fast. Better to hire out your aluminum work if you can’t fit a bigger power source.
Using a spool gun can let you use a more compact power source, but then we’re talking about budget ceilings. Small and powerful is expensive.

 

[rslifkin]

could you recommend a small welder that can weld alum plates, like this hoist system mount?

The smaller Eastwood MIG welders (the MIG140 is the current model) have a spool gun attachment available to allow them to weld aluminum. They're probably one of the cheapest options that can do it, although you do have to switch between the regular gun and the spool gun for aluminum vs everything else, and aluminum also requires different shielding gas than steel or stainless steel. As noted above, aluminum requires a good bit of power, the MIG 140 with the spool gun attachment is only recommended for up to 1/8" thick aluminum.

Before you go out and buy a welder and put in the time to learn to weld, I'd give some thought to how often you're likely to use it. If it's a lot, then go for it. But if it's for a once a year thing that wouldn't be crazy expensive to have done professionally, it might not be worth the cost and space to own the welder.

 

[paulga]

The smaller Eastwood MIG welders (the MIG140 is the current model) have a spool gun attachment available to allow them to weld aluminum. They're probably one of the cheapest options that can do it, although you do have to switch between the regular gun and the spool gun for aluminum vs everything else, and aluminum also requires different shielding gas than steel or stainless steel. As noted above, aluminum requires a good bit of power, the MIG 140 with the spool gun attachment is only recommended for up to 1/8" thick aluminum.

Before you go out and buy a welder and put in the time to learn to weld, I'd give some thought to how often you're likely to use it. If it's a lot, then go for it. But if it's for a once a year thing that wouldn't be crazy expensive to have done professionally, it might not be worth the cost and space to own the welder.

from the information i gathered at this point, for proper looking results on alum it needs to be done inside with an AC TIG welder, so it maybe cost effective to find a contractor.

 

[paulga]

A 20 amp breaker should be ok. If it can’t handle the inrush current, you can look for a different trip curve breaker.
Also remember, that’s max, not what you’d likely be running at.

this is another model i checked last time, it recommends NEMA6-50 should be used for the power outlet. it also provides a 220>110v power adapter to run in a 110v circuit with a reduced output. Should the circuit breaker be 40a in a 110v circuit, and 30a in 220v?

 

[Bmarler]

this is another model i checked last time, it recommends NEMA6-50 should be used for the power outlet. it also provides a 220>110v power adapter to run in a 110v circuit with a reduced output. Should the circuit breaker be 40a in a 110v circuit, and 30a in 220v?

View attachment 160543

Those breaker sizes would be the minimum I’d use, and would handle most things you’d be doing. That said, if you were running to the upper end of the welders capacity, you may have a breaker trip now and then.
For example, I run a millermatic 251 off of a 30 amp 240 volt breaker and it only trips if a run it hard.
I also run a thermal arc 185 off a 30 amp 240 volt breaker and I don’t think it’s ever tripped.

 

[ronobrien]

Has anyone used a handheld arc stick welder?

It's said to be sufficient for light home projects, and portable. It has a plug that fits any standard duplex receptacle. While normal bulky welders require at least 20+ amp input, this welder's wire is 14 gauge which is rated for 15amp. So the wattage should be capped at 1875w. How can it have 4,600w rated "input power"?

Amazon.com

View attachment 160230

View attachment 160231

I read some reports and they were pretty unanimous. JUNK. Modern IGT welders are pretty inexpensive, multi use and are more forgiving for less experienced welders. They also hold voltage/amperage more steadily that the old BUZZ boxes. I started welding in the 80's with a Lincoln 225 BB and bought an IGT welder several years back. AMAZING difference. Check Harbor Freight. They have some pretty decent stuff for home DYI types.