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So, I have been wondering about grounding my work. I have always been under the impression that you wanted to keep the ground as close to the work area as you can. How important is this? Can I just clamp my ground to my table and lay my working pieces on the table? I was doing some work over the weekend and had the clamp on the table, but not on either of the pieces to be welded together. I seemed to be getting a little more splatter than normal. I am low on gas, so I'll be getting a new bottle tonight, but I think I was still getting gas to the tip. Do I need to at least clamp my work to the table if I am grounding to the table itself?
Reply:My table is grounded, we clamp to it for plasma and sticks and normally use the lead from feeders to the work piece but it can work either way.www.urkafarms.com
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Originally Posted by Ron_J
Can I just clamp my ground to my table and lay my working pieces on the table?
Reply:Here's the thing. I am assuming you are using MIG. MIG needs a very good ground to be most effective, and give the least issues. You can clamp to the table, but you need to make sure the connection between your table and the material being welded is good. I find that if I have some rust, spatter, etc. then at times my MIG will sputter. I will then either clamp to what I am welding or run a flap disk over my welding table to clean it up. Make sure where you are clamping to the table is also bright shiny metal. The other thing to consider is are you willing to risk arc marks? I find that sometimes when I clamp to the table, if the piece I am welding moves at all, I can end up with arc marks on the table and the item being welded.Miller Multimatic 255
Reply:Yet another thread where the concept of "ground" gets confusing when people start talking about grounding tables, etc. Some people actually ground their welding tables. This is simply talking about a work clamp to complete the weld circuit with the machine.Yes, I know "everybody knows" but it's not always clear. If the work clamp is a long way from the weld, or has poor contact you will definitely get more spatter, inconsistent starts, etc. MIG and stick seem to be more prone to this than TIG.Check out my bench vise website: http://mivise.comMiller Syncrowave 250DXMillermatic 350P with XR AlumaProMiller Regency 200 with 22A feeder and Spoolmatic 3Hobart Champion EliteEverlast PowerTig 210EXT
Reply:With stick and TIG grounding is not bad.If you MIG or Fluxcore keep the close or will effect your weld. It changes the voltage. I start out with just stick and ground could be 30 feet away. But when switched to Fluxcore found out the ground need very close for a stable welded.Dave
Originally Posted by Ron_J
So, I have been wondering about grounding my work. I have always been under the impression that you wanted to keep the ground as close to the work area as you can. How important is this? Can I just clamp my ground to my table and lay my working pieces on the table? I was doing some work over the weekend and had the clamp on the table, but not on either of the pieces to be welded together. I seemed to be getting a little more splatter than normal. I am low on gas, so I'll be getting a new bottle tonight, but I think I was still getting gas to the tip. Do I need to at least clamp my work to the table if I am grounding to the table itself?
Reply:As mentioned, the term "ground" as applied to a welding circuit is incorrect per AWS terminology. The "proper" AWS term to use is work clamp or work connection not ground clamp because you aren't connecting to an earth ground with that connection (or if you are there's not much welding that'll happen). Welding power supplies should also be connected to an earth ground, just as an electrical component should be otherwise you can agitate the electrical pixies into murdering you or something else connected to the same wiring as the welder.The idea with attaching the work clamp as close as possible to the weld joint is to minimize resistance in the welding circuit, which is particularly important with the wire fed processes since they use Constant Voltage power supplies.Per Ohm's law Voltage = Current * ResistanceTIG and stick use constant current power supplies, GMAW/FCAW are constant voltage. The two types of welding power supply handle changes in resistance, voltage and amperage differently. Constant current you set the amperage and let the machine try to give you that amperage by varying the voltage based on the resistance of the welding circuit from the power supply to the torch, through the arc and weld puddle then back through the work clamp to the power supply again. It's also why increasing arc length increases your voltage, because you're adding resistance and the machine ups the voltage to keep the amperage where it's supposed to be. There's less resistance in this type of welding circuit because there's a relatively simple connection between the electrode and torch. Changes in voltage are also less problematic for either process unless they're extreme, so extra resistance from poor work clamping isn't as noticeable. Constant voltage you're doing it the other way, setting the voltage on the machine then letting it handle the amperage, usually via wire feed speed, to account for the specific resistance in the weld circuit. There is quite a bit more resistance in these welding circuits because the electrode (the wire) is consumable and it's being fed into the puddle where it only makes electrical contact at the contact tip (or somewhere in the liner if you're running hot wire). This is why stickout is so important, because the more wire sticking out the more resistance you're creating, and the more amperage the machine gives you to maintain the pre-set voltage. If you throw a poor work clamp connection on top of the normal small variations in stickout due to the human factor, the machine will have to increase amperage even more to overcome the added resistance. Excessive amperage is one of the things that causes excessive spatter for MIG, so having low resistance in the welding circuit is important if you want to run a given voltage/WFS without problems.
Reply:Current coming from your power source is a series circuit. DC it flows from the welder through the work clamp, through the workpiece, across the arc, back up the torch to return to the welder. Direction may vary or alternate. All conductors share voltage. might get most of the voltage across the arc, but a high resistance work clamp connection, or poor conduction between table & workpiece will steal some of the voltage. A sputtery connection alternates between using little voltage & most of it. Clamping to workpiece is usually best, but sometimes reasons to not do that prevail. TIG welding, I have an aluminum table, conducts pretty well. I usually lay a heavy copper bar 18" long on the workpiece to ensure a good ground.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:I do metal artwork and this is what I made up. The small clamp is great to attach to your work. It's light and usually won't twist or turn your piece like typical round clamp. It's from a dead battery charger.
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Originally Posted by Ron_J
So, I have been wondering about grounding my work. I have always been under the impression that you wanted to keep the ground as close to the work area as you can. How important is this? Can I just clamp my ground to my table and lay my working pieces on the table? I was doing some work over the weekend and had the clamp on the table, but not on either of the pieces to be welded together. I seemed to be getting a little more splatter than normal. I am low on gas, so I'll be getting a new bottle tonight, but I think I was still getting gas to the tip. Do I need to at least clamp my work to the table if I am grounding to the table itself?
Reply:If I'm having trouble with ground a part on the table, I just tack weld it down, do my welding, then grind the tack off. Given, it's not a fancy fixture table... just a steel plate. For grounding for grounding to a table, I have a Dinse style lug that bolts to the table. Put the male end on the end of a ground lead, then you can just plug the ground into the table and give it a 1/4 turn.Sent from my Lincoln Buzzbox using Tapatalk
Reply:I never have a problem clamping the work clamp to the table, just keep the clamp clean, and where you attach it to the table , and the surface, you'll have no issues. Sent from my SM-G973U using Tapatalk
http://www.philswelding.com
Reply:Ground contact.
Sent from my Lincoln Buzzbox using Tapatalk
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Originally Posted by MetalMan23
I never have a problem clamping the work clamp to the table, just keep the clamp clean, and where you attach it to the table , and the surface, you'll have no issues. Sent from my SM-G973U using Tapatalk
Reply:I've had burn marks on the work & table where they don't make good contact.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:As close as possible, sometimes that isnt on the part but ideally you want the ground on the part you are welding. Ive seen some real messes caused by the ground being to far away. An example someone grounded the machine to the frame of a truck and then did some welding on the driveline, the result was some pitted and noisy bearings in the transmission I had to replace. As close as possible is the best bet even if its not running current through bearings or thin stuff theres a good chance that you can fry some electronics if you are running 100s of amps through a long circuit that they are grounded to. This is absolutely critical on modern equipment, not so much on old equipment or non mechanical things (barges,pipelines, buildings, ect) but still a good habitat and results in less weld quality issues.
Reply:When I built my welding table, I did some very thin light air brushing on top (rust protection and appearances) that I thought I would have to grind off right away. 2 yrs later 98% of the air brush work in still intact because it was so thin. I do have a couple small burn marks from "being stupid" and moving the item being welded so I do like the third hand concept. I have been thinking about adding a 2nd ground (sorry) from the table to the item with a magnet just to make sure the work gets full current. I think Lis2323 has a couple that he has added to his tables.The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
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Originally Posted by whtbaron
When I built my welding table, I did some very thin light air brushing on top (rust protection and appearances) that I thought I would have to grind off right away. 2 yrs later 98% of the air brush work in still intact because it was so thin. I do have a couple small burn marks from "being stupid" and moving the item being welded so I do like the third hand concept. I have been thinking about adding a 2nd ground (sorry) from the table to the item with a magnet just to make sure the work gets full current. I think Lis2323 has a couple that he has added to his tables.
Reply:Nice looking I like the Miller type as make that type on lathe out of scrape brass.Dave
Originally Posted by 52 Ford
This is the style ground lug I was talking about. https://www.amazon.com/COMBO-Lenco-C...a-753062597975Then you can make up a short ground lead and take it off when you don't need it.Sent from my Lincoln Buzzbox using Tapatalk
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Originally Posted by shovelon
Nope. If your table is clean, just lay your weldments on the table. Use the table to complete(ground) the circuit to the welding machine. And the third hand like mentioned above is a good supplemental circuit insurance. Once had a dodgy welder seller tell a forum member here who was having arc start problems that it is always necessary to mount the ground clamp on the work. Not in production shops it is. I put mine on a lug under the corner of my benches leaving me with all this table surface to weld against.
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Originally Posted by smithdoor
Nice looking I like the Miller type as make that type on lathe out of scrape brass.Dave
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Originally Posted by shovelon
To expand on my comment, I just got finished tonight on a project welding 4130 structures about the size of a beer stein. In total there were just shy of 1300 individual welds, all of them sitting on my bench about 2 to 3 feet away from the corner of my steel table where my ground clamp is attached. Not one arc pit on the table and no problems with arc starting. It does help to have quality equipment to work with. Again I avoid attaching the work lead to my parts like the plague. Just not productive.As far as welding on vehicles I disconnect the battery and weld away. Keeping the work lead close is logical to avoid passing current through vulnerable parts.
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Originally Posted by 52 Ford
That's important on a lot of mechanical stuff. Passing electricity through a bearing usually doesn't work well...Sent from my Lincoln Buzzbox using Tapatalk
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Originally Posted by shovelon
To expand on my comment, I just got finished tonight on a project welding 4130 structures about the size of a beer stein. In total there were just shy of 1300 individual welds, all of them sitting on my bench about 2 to 3 feet away from the corner of my steel table where my ground clamp is attached. Not one arc pit on the table and no problems with arc starting. It does help to have quality equipment to work with. Again I avoid attaching the work lead to my parts like the plague. Just not productive.As far as welding on vehicles I disconnect the battery and weld away. Keeping the work lead close is logical to avoid passing current through vulnerable parts.
Reply:I never disconnect. 1000;s of accidents and damage to equipment each year fooling with batteries. Muffler shops weld on cars daily, new trucks used as welding platforms. Like a lot of stuff one never knows weather that recommendation was well researched or now one can do that with a few clicks then the engineer says that makes sense and now its in a manual,,,, "just in case". Not as much dauly now, did exhaust last week, I weld on a couple cars or equipment most weeks. In the past sometimes several daily and have heard of a coup[le ground wires, binds getting welded and over the years a bearing or 2 but damage is so rare I really cant even think of a legit case even from the net where something major was ruined. I was trying to think and come up with a number of cars, trucks, tractors, cranes, couple planes, couple trains but cars and trucks got to be north of 5000, never had an incident. I remember this on SFT and a kid says ,,, he blew out all the lamps, cooked all the wires and had fireworks,,, just nonsense. Clamped to a loader bucket, wouldnt even occured to me to do anything else. I have never heard a real explanation on how unhooking a battery does anything in this respect,,,, seems every time I ever asked the ? usually got a response like,,, I was always told, etc but I even ask some real savvy tech types and never get the straight dope.Last edited by Sberry; 2 Weeks Ago at 08:16 AM.www.urkafarms.comLike a lot of other subjects that have seemed to grow,,, no real stuff but now2 legend. I mention issue somewhat similar, at convention of fire investigators and I ask 200 of them, not one hand goers up,,, but read a post and it will surely happen to you. Be different if we saw one, or one once in a while but NEVER is different. Seems if it happen given the numbers welded on we would see one weekly,,, monthly at least?www.urkafarms.com
Reply:My bench sits on a bonded beam and have an extension with connector FROM it.
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www.urkafarms.com
Reply:Just remember that electricity will ALWAYS find the shortest path to complete the circuit. If you put work clamp on the front of a a vehicle & weld on the back then current will travel through the entire vehicle to complete the path. There is a possibility of the current finding a nice low resistance copper path through a computer. If you clamp on the rear bumper to weld on the drive line - current is going to go through gears & bearings - probably through the read end. If you clamp the rear bumper to weld on the trailer hitch current stays in the rear bumper.Just think for a minute before you hook up - What is the current going to go through? What is shortest path to complete the circuit?
Reply:Like the cutting table Dave
Originally Posted by Sberry
My bench sits on a bonded beam and have an extension with connector FROM it.
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Originally Posted by 52 Ford
That's important on a lot of mechanical stuff. Passing electricity through a bearing usually doesn't work well...Sent from my Lincoln Buzzbox using Tapatalk
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Originally Posted by Bob
It can work pretty well also. My live welding cable reels are made from trailer axle hub and spindle and have been working just fine for 37 years now with no problems.
Reply:Bob - wonder how long those hub bearing would last if you put them on a trailer - running 70mph. You will never notice arc marks on the roller bearing in a cable reel situation - but probably would in a high speed, loaded with weight condition.Nothing wrong with your set up - I learned how to make them reels 40 years ago - they have been around for a long time & work very well.
Reply:Bad ground contact...
The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:All the steel in my place is bonded. Rod welded from the bench to the building.www.urkafarms.com
Reply:Now to rebuild after ground contact. Get the JB WELD and start fixing. Dave
Originally Posted by whtbaron
Bad ground contact...
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发表于 2022-9-16 15:52:13