What am I doing wrong?

[JimGnitecki]

Yes, I am turning the grounding plug in tightly. And I do have two ideas already about how to improve the grounding on the aluminum weld coupons that are my training workpieces:

Idea 1: I think I will start placing the freshly cleaned (s.s. wire brush and then Acetone) workpiece coupon so that it lays upon, and bridges the gap between, two other weld coupons. This will leave a GAP between the workpiece coupon and the tabletop.

That will allow me to clamp my grounding clamp directly to the weld coupon at a location that does not impair my setup ergonomics and torch welding path. And I can also then MOVE the grounding clamp as needed to keep it away from my welding path as I weld on different locations on the coupon.

Idea 2: Also, I keep reading everywhere how the grounding clamps provided with most welding machine kits are "cheap" and marginal as a result. What grounding clamps are the best for actual reliable and durable grounding, and where can I buy one? And, since a physically smaller grounding clamp would be easier to work around with my mostly small scale work, where can I buy a really GOOD but also relatively physically SMALL grounding clamp? (I say clamp, because when TIG welding aluminum, a "magnetic" ground won't work!)

Jim G

 

[van123d]

I have no experience with this clamp but saw it recommended recently on this forum by multiple people and was thinking of getting one myself.

US Forge Welding Heavy Duty Bronze Ground Clamp 300 Amps : Amazon.ca: Tools & Home Improvement

US Forge Welding Heavy Duty Bronze Ground Clamp 300 Amps : Amazon.ca: Tools & Home Improvement

www.amazon.ca

 

[Aliva]

Tweco Copper Ground Clamp

Tweco copper alloy clamshell ground clamp GC-200, GC-300 and GC-500. 9205-1120, 9205-1130, 9205-1150

canadaweldingsupply.ca

 

[JimGnitecki]

Wow! Both of those suggested clamps look like a HUGE improvement over the wimpy one that came with the machine! I will examine both advertisements and buy one! Looks like that first one comes from The U.S. so is subject to customs delays, but probably worth the extended wait!

Jim G

 

[JimGnitecki]

I examined all the Amazon.ca weld clamp offerings, and realized how important the QUALITY, the SHAPE, SIZE, and the DELIVERY reliability of the ground clamps offered really are!

I found that:

- The excellent clamp mentioned by Van123D looks REALLY good, except for 2 issues that ultimately ruled it out for me: size and delivery performance of ALL the vendors who offer it on Amazon. This clamp is about a foot long, so is just physically too bulky for the type of welding I will be doing. I also checked the delivery performance all ALL the vendors who offer it on Amazon.ca, and their track record on delivery is really awful. The highest satisfaction rating was only 77% which is par for really bad, and most reviewers commented on how long it took to actually arrive.

- The one mentioned by Aliva has a shape that won't work for me. BOTH of the jaw halves are very curved, which makes it impossible to slip one jaw under my weld coupon workpiece, which for stability reasons will always be only slightly elevated above the welding table. Neither of the deeply curved jaws would fit under the weld coupon, between it and the tabletop.

The one I actually ordered was the 200 amp (see photo attached) versus 300 amp version of the Forney offering on Amazon.



I would have preferred the 300 amp version, which was only about 40% larger, but the delivery time was very extended and questionable on that one, whereas the 200 amp version will get here by January 31, and is more than adequate for my maximum 200 amp welder and my planned workpieces.

Here are the features I like about it:

- Brass construction
- Robust at 0.75 lb weight
- Allen-tightening threaded screw capable of handling large ground cable
- FLAT blade on one side, looks like about 3/16" thick, which will easily slide under my elevated training coupon workpieces
- The spring is completely sheltered. This is not important with clean TIG welding, but super important for stick welding (MIGHT do sometime)
- Overall length is 5 inches, and width is just under 1 inch, which is GREAT for my planned workpieces
- The jaws have a nicely extended "parallel" actual contact area, versus the very "narrow angled line" contact area on many cheaper clamps
- The jaws are grooved and also come with shim stock
- The spring pressure is described by reviewers as strong but not too hard to handle
- 3/4 inch jaw opening, which is adequate for my planned workpieces
- Price was appropriate for the quality and feature level, and includes free "Amazon Prime" delivery

I have a plasma cutter coming, and may end up buying one more of these for that, should the provided grounding clamp there also merit replacement.

Jim G

 

[Rauce]

I weld a fair amount of aluminum and originally learned aluminum tig welding in a college course. Always used a steel welding table for aluminum coupons in school.

For the aluminum work I do now I’m usually clamping directly to the work.

I often use 99% isopropyl for cleaning. When I really want to be sure it’s clean I use lab grade acetone just because I’ve got some (for titanium) but it’s probably overkill on steel or aluminum.

 

[JimGnitecki]

I think I may have identified an inexpensive way to elevate the aluminum weld coupons sufficiently to enable clamping the new lower profile brass ground electrode I spoke of above directly to the coupons:

Home Depot sells 3/4" x 3/4" aluminum U-channel "plywood trim" in 8' lengths. I plan to buy one piece, cut it into 12" lengths, and lay a 6 inch weld coupon across 2 of the U-channel pieces to elevate it, and clamp the ground clamp directly to the coupon.

Yhe direct ground connection should eliminate any inadequate grounding issues, and the aluminum u-channels can't contaminate the aluminum. Pretty simple. Should work?

Jim G

 

[Rauce]

I mean that would work but I don’t think using a steel table is going to contaminate your coupons if it’s clean.

I have a cheap steel welding table from PA that’s 3/16” zinc plated with 5/8” holes all over it. When I do coupons to warm up on occasion put them right on the table and clamp them down.

 

[phaxtris]

You really don't need an aluminum table, I have Tig welded hundreds and hundreds of critical aluminum parts on a steel table, critical like general dynamics contracts with extreme levels of inspection, to the point of if there is a deficiency (bad weld, crack, contamination) the whole part got scrapped, and never did a part get scrapped for contamination

 

[JimGnitecki]

I mean that would work but I don’t think using a steel table is going to contaminate your coupons if it’s clean.

I have a cheap steel welding table from PA that’s 3/16” zinc plated with 5/8” holes all over it. When I do coupons to warm up on occasion put them right on the table and clamp them down.

So you do not clamp the ground clamp directly to the coupon workpiece?

Jim G

 

[trevj]

Personally, I think your worries about a steel table somehow contaminating your weld, are pretty far fetched. Aluminum kinda sucks, as it does form an oxide layer. checker plate is a long ways from flat, on either side, too.

You CAN cross contaminate by using the same grinding wheels and such. But it really is only going to make a difference to your welds, once you get pretty far along, and start x-raying your welds for process compliance. My advice at the learning stages, don't concern yourself with it all that much. Nice to know, but it doesn't affect your life!

True story, I doubt I have cleaned anywhere near half the aluminum I have welded, and it all stuck together just fine! I was not welding to code, I was making boxes and similar projects. Most of what I did clean, was a quick pass down the edges with a abrasive mesh wheel on a die grinder, mainly to knock back any paint. The self cleaning action of an AC arc, has some pretty solid power!

You DO have the High Frequency on constantly, yes? Could not recall reading that it was, just that you got HF at the start, and it went away. Which sounded like HF start only, rather than Continuous. AC aluminum welding needs the HF on at all times.

I learned most of what I do know about welding, in a Military Aircraft Structural repair environment. All the tables at the shops I worked in, were steel. So were the ones at the College I spent over a year in, learning the basics their way. What jigs (cupon welding, back purge jigs) we had that were not steel were a combination of steel and brass. And those WERE being used to do welds that were tested, in order that the welder could maintain his or her qualifications.

If you have some steel sheet metal on hand, bend up a corner of a piece, so that you can place it on the table flat, and still clamp the ground to it.

Keep in mind, ground clamps are subject to wear and tear, and a quick pass with a file can make a difference in the contact patch there as well. Any time the current is forced to jump the gap, or run through a concentrated point, it burns both the metal, and the ground clamp.

 

[JimGnitecki]

You really don't need an aluminum table, I have Tig welded hundreds and hundreds of critical aluminum parts on a steel table, critical like general dynamics contracts with extreme levels of inspection, to the point of if there is a deficiency (bad weld, crack, contamination) the whole part got scrapped, and never did a part get scrapped for contamination

Yes, I might be a bit more picky than needed, but there is no harm in doing so, right?

Jim G

 

[trevj]

Yes, I might be a bit more picky than needed, but there is no harm in doing so, right?

Jim G

Yeah, there is, if it interferes with your success.

Better things to worry about, IMO.

 

[Rauce]

If the piece is clamped to my table I’ve got the ground on the table.

Where your approach might be harming you is that you’re adding an additional layer of aluminum oxide, which is a bad conductor.

 

[JimGnitecki]

. . .

1. You DO have the High Frequency on constantly, yes? Could not recall reading that it was, just that you got HF at the start, and it went away. Which sounded like HF start only, rather than Continuous. AC aluminum welding needs the HF on at all times.

. . .

2. If you have some steel sheet metal on hand, bend up a corner of a piece, so that you can place it on the table flat, and still clamp the ground to it.

3. Keep in mind, ground clamps are subject to wear and tear, and a quick pass with a file can make a difference in the contact patch there as well. Any time the current is forced to jump the gap, or run through a concentrated point, it burns both the metal, and the ground clamp.

1. Yes, I have a Canaweld AC-DC TIG 201 Pulse D and am currently running AC mode using 25% balance. No pulsing yet.

2. I figure the aluminum 3/4" x 3/4" u-channel pieces will enable clamping as described above.

3. Ah, so grounding clamps can also require inspection and maintenance. I'll keep that in mind.

Thanks for the reply, trevj. I am learning a lot from the forum comments and questions.

Jim G

 

[JimGnitecki]

If the piece is clamped to my table I’ve got the ground on the table.

Where your approach might be harming you is that you’re adding an additional layer of aluminum oxide, which is a bad conductor.

You might have misunderstood my plan. I will be clamping the ground clamp directly to the weld coupon. The u-channel will be there merely to elevate the coupon above the table by 3/4" so that I can get the bottom scissor under the coupon's underside surface, without tilting the coupon.

Jim G

 

[phaxtris]

Yeah, there is, if it interferes with your success.

Better things to worry about, IMO.

What I'm getting at is don't worry about using a steel table, it's not worth any additional expense to have an aluminum table strictly for welding aluminium

The oxide layer being a problem is debatable, but not impossible. I have welded many things off an aluminum truck deck (skid work table or whole deck) and never had a problem, and that is an aluminum work surface sitting in the elements 24/7....but it's not impossible

 

[trevj]

1. Yes, I have a Canaweld AC-DC TIG 201 Pulse D and am currently running AC mode using 25% balance. No pulsing yet.

2. I figure the aluminum 3/4" x 3/4" u-channel pieces will enable clamping as described above.

3. Ah, so grounding clamps can also require inspection and maintenance. I'll keep that in mind.

Thanks for the reply, trevj. I am learning a lot from the forum comments and questions.

Jim G

I have, and do, use old school transformer machines, so my grasp of the fancier settings, is largely theoretical, take that as it may be.
There a reason for the balance to be set to 25%? I think I would set it midrange, and forget about it for a while, until you can get good results without the bells and whistles.

At school, we ran beads, built up layers of beads, and ran beads across those, as we learned the basics. We learned heat control by building up vertical columns, or by stacking weld bead to build arches across open space.

If you have not watched any of his videos yet, YouTube username weldingtipsandtricks is worth the time! Good practical advice, and some great up close views of what is going on in the weld puddle!

 

[trevj]

You might have misunderstood my plan. I will be clamping the ground clamp directly to the weld coupon. The u-channel will be there merely to elevate the coupon above the table by 3/4" so that I can get the bottom scissor under the coupon's underside surface, without tilting the coupon.

Jim G

Do be aware that you may be introducing yet another variable in, and that is the issue of having your puddle decide to fall out the underside of your weld, if the weld area is unsupported.

Not something that you will not have to learn to deal with, but at the early stages, it is enough to be able to run a decent bead and keep it consistent.

IMO, having too many problems to solve at once, can markedly interfere with getting any progress on the basic hand skills that are needed.

 

[JimGnitecki]

What I'm getting at is don't worry about using a steel table, it's not worth any additional expense to have an aluminum table strictly for welding aluminium

The oxide layer being a problem is debatable, but not impossible. I have welded many things off an aluminum truck deck (skid work table or whole deck) and never had a problem, and that is an aluminum work surface sitting in the elements 24/7....but it's not impossible

The aluminum table top was not an extra expense for me. I bought the diamond plate aluminum from a fab shop that had a huge surplus of it, so I actually spent less than I would have for steel!

I think it's hard to know which is potentially the bigger potential issue for grounding: the aluminum oxide layer OR the cheap OEM clamps supplied with welding machines? This is why I am now going to use the higher quality Forney brass clamp AND connect it directly to the workpiece, right after brushing the workpiece with a s.s. wire brush in one direction only and then using Acetone as the final cleaning.

With:
- a high quality and solid brass grounding clamp
- connected directly to the workpiece
- on a workpiece that has been deoxidized and then washed with Acetone

I think I will have done everything I should to enable the best possible grounding.

Jim G