Welding Tips and Tricks

Hello everyone!
I'm about to purchase a beginner tig welder, but the last unanswered question (before making the decision which to buy) is related to my biggest fear: the start and end of a weld in thin aluminum material.

If I had a video suggestion for any of the pro welders/teachers on youtube it would be on this subject.

So my question is: in order to taper off the amperage at the end of a weld in thin aluminum, are most machines able to reduce the arc to such miniscule levels like Jody shows in his videos? He often "swirls" the arc a little right at the end and tapers power down to almost nothing (so he ends up with no craters and no blobs) And same goes for starting the arc ( in HF)

A good example video for the arc starting is "Aluminum TIG Welding Techniques | Welding Tips & Tricks" at 1:44 mark for the arc START, and 8:11 for ENDING the weld (https://www.youtube.com/watch?v=NQ4nbxz9o4c

I am well aware that this technique is mostly experience, but want to purchase a capable machine if possible in my "beginner budget."

I'll try to attach a snapshot of my list of welders I'm considering, but basically narrowed it down to:
Weldpro 200DG (10-200 AC amps in Tig mode)
Primeweld 225x (10-225 AC amps in Tig mode)

I have very little welding experience only with stick and aluminum mig spool gun, and starting/ending the welds were the toughest to do with thin material. Perhaps it's very different with TIG and I'm making it a bigger deal than it is, because TIG has so much more control.

Any input is appreciated.

That tapering of the arc (amperage) is actually performed by using a foot pedal. The pedal functions just like a gas pedal in your car. The harder you push it, the more amps it produces relative the the machine’s settings (User adjustable).

Think of it this way: your pedal can deliver from 0-100% of the amps you set the machine for, let’s say 60 amps. You’re welding thinner metal and to initiate a puddle takes 55 amp. You need full pedal. You are welding away and the length of the bead, material type, etc begins to absorb so much heat that now you only need 34 amps to maintain your puddle. So you simply ease off the pedal like you would entering a School Zone in your car where the standard speed is 50 MPH.

And as you approach the “Stop Light” you merely taper off gently to no pedal, and use your arm or hand to lightly swirl the torch to prevent leaving that crater. Any machine with a pedal or torch switch can do this.

You can also do this to some degree with “Slope” adjustments on your welder. Slope is less nuanced and delivers only exactly the amps for the designated time, no feathering of it with your foot or hand.

Allay your fears, buy the machine you find to suit your budget and interest. And get a pedal with it

Thank you for the reply!

Yes, I understand how the pedal works, I just wanted to make sure the machine I'm purchasing can taper off that much - some are able to get down to 20 amps and some to 10 (in AC tig mode.) I didn't want the machine to "cut the arc" because it only goes down to 20 amps when I actually need [let's say] 12 amps.

But if you're saying the amperage at the end of those welds is in the 30+ amps range, I really should not worry about the machine. In some videos it looks like he takes the machine down to just a few amps before the arc is cut, but that just goes to show how little I know about how many aps it takes to keep the arc.

So in theory, either machine could weld the bottom of a beer can (not that my cans need repairing )

Really good to know, thanks again! I look forward to reporting that my aluminum coupons have not turned into a puddle

So how much thin aluminum welding do you currently do or do you expect to do? People tend to worry about features that for 90% of us have no bearing on the actual projects we routinely tackle. Even if you buy a machine with a "high" starting/ending amperage, there are plenty of techniques to mitigate that issue (welding spoons, chill blocks, run-on and run-off tabs, etc.).

I suspect if you really think about the projects you want to do, starting amps is going to be one of the last parameters you need to worry about.

Louie1961 wrote:So how much thin aluminum welding do you currently do or do you expect to do? People tend to worry about features that for 90% of us have no bearing on the actual projects we routinely tackle. Even if you buy a machine with a "high" starting/ending amperage, there are plenty of techniques to mitigate that issue (welding spoons, chill blocks, run-on and run-off tabs, etc.).

I suspect if you really think about the projects you want to do, starting amps is going to be one of the last parameters you need to worry about.

Very true. As a beginner, one does not think that there are other tricks to addressing the issue (I will look into the mentioned solutions, thank you.)

The main reason I'm getting a tig welder is to be able to fabricate an aluminum roof rack for my van. Not sure of the exact wall thickness of tubbing but an initial search yielded the following results for 1.25 diameter: 0.065, 0.095, 0.12 inches. I might not go for the 0.065 but at the same time don't want to omit the option just because my welder can't go low enough in amperage.

Cheers!

Use 1.25 tubing with 1/8" wall. It will be plenty strong enough.

There are some "tricks" to welding these tube sections together...
First, when you cut the "bird's mouth" (cope) the flared ends are very thin-walled. Don't start your arc there; start on the saddle.

Second, when tubing terminates into others, and both ends are welded shut, you can blow out the final bit of weld due to trapped gas and heat. You either need a vent hole in the intersection of the tubes, or, you can put a hole in the length of the tube, or, you can "almost" close the weld then wait for the gas and heat to dissipate before quickly closing it up.

Aluminum in general twists, racks, and pulls heavily while welding. Go SLOW. Tack everything up only, everywhere, multiple tacks per piece. Don't weld out a single joint, do sections, skip to another area, weld some, jump around again, etc. This patient approach can help minimize distortion. A lot!

Frequency adjustment (Hz) and Balance are pretty advantageous for this type of work. Small diameter tubes are tricky to weld. Lots of re-positioning as you go. And clean the outside and inside of the tube ends. The debris internally will come back to bite you when welding.

cj737 wrote:Use 1.25 tubing with 1/8" wall. It will be plenty strong enough.

There are some "tricks" to welding these tube sections together...
First, when you cut the "bird's mouth" (cope) the flared ends are very thin-walled. Don't start your arc there; start on the saddle.

Second, when tubing terminates into others, and both ends are welded shut, you can blow out the final bit of weld due to trapped gas and heat. You either need a vent hole in the intersection of the tubes, or, you can put a hole in the length of the tube, or, you can "almost" close the weld then wait for the gas and heat to dissipate before quickly closing it up.

Aluminum in general twists, racks, and pulls heavily while welding. Go SLOW. Tack everything up only, everywhere, multiple tacks per piece. Don't weld out a single joint, do sections, skip to another area, weld some, jump around again, etc. This patient approach can help minimize distortion. A lot!

Frequency adjustment (Hz) and Balance are pretty advantageous for this type of work. Small diameter tubes are tricky to weld. Lots of re-positioning as you go. And clean the outside and inside of the tube ends. The debris internally will come back to bite you when welding.

Thank you so much for this info! Much appreciated!

Would something like purging the tube with argon make any difference? Not that I need to make this any harder

Hey, newbie here as well, however I figured I'd post my $.02 as I just got the Primeweld Tig225 and have been using it for a few weeks now. Obviously I still need to build up my seat time but I was running the aluminum/steel drill you might have seen on the TFS channel and Jody do at one time. On the edge bead practice, I did notice the starting amps were rather high on the Primeweld. To be fair, I don't have a lot of seat time maybe 8 hours total now and I haven't tried the techniques Louie1961 mentioned. Even after I just barely press the foot pedal to initiate the arc the amps start hot enough to melt down the edge of the aluminum (.080 @80amps) and rolled back the edges on steel (.135@125amps). Then after a second or two the amps die down to barely heating up the metal and I can press harder to move forward from there.

I remember hearing something Mr. Tig said that some lower budget machines are not able to do that nice low amp start. I am curious as to how that works physically/electronically on the lower budget machines. Hopefully someone can chime in to explain.

Cheers

Not needed at all. That is required for stainless and titanium, but not for carbon steel and aluminum.

I tend to use 1-2 seconds of preflow (for lower amperage aluminum, helps stabilize the arc more quickly) and I add 8 seconds of postflow to protect the weld from hot-short cracking, and to protect the tungsten from oxidizing. You can experiment with flow times to suit your application and outcomes.

TigTag wrote:The main reason I'm getting a tig welder is to be able to fabricate an aluminum roof rack for my van.
Cheers!

Honestly, since you already have MIG experience, I would use MIG for your project. The learning curve for TIG on thin wall tubing is going be very steep. While some folks would say TIG is better fr such a project, I am not convinced. But MIG has its own learning curve and you will likely have to buy a spool gun.

And for that matter, why not just go with steel tubing and use the MIG you already have? You aren't going to save much weight on a roof rack by switching to aluminum. 1 inch by 1inch by 1/8th inch aluminum square tube (thinnest I could find on metalsdepot.com) is 0.3 lbs per foot. 1 inch x 1 inch by 16 gauge steel square tube is 0.73 lbs per foot.

I mean if you use 80 linear feet of tube (probably the high end), the weight difference is is about 43 pounds (not much). If you want to try to cut that difference, go with smaller size square tube (1/2 inch x 1/2 inch by 16 gauge is 0.31 lbs per foot.)

Louie1961 wrote:And for that matter, why not just go with steel tubing and use the MIG you already have? You aren't going to save much weight on a roof rack by switching to aluminum. 1 inch by 1inch by 1/8th inch aluminum square tube (thinnest I could find on metalsdepot.com) is 0.3 lbs per foot. 1 inch x 1 inch by 16 gauge steel square tube is 0.73 lbs per foot.

I mean if you use 80 linear feet of tube (probably the high end), the weight difference is is about 43 pounds (not much). If you want to try to cut that difference, go with smaller size square tube (1/2 inch x 1/2 inch by 16 gauge is 0.31 lbs per foot.)

Aw come on man, here was my one good excuse to finally buy a AC tig welder and this good logic is not helping my cause

I don't have any welders now. The mig with the spool gun I bought and used about 15 years ago to make computer frames (open-frame setup for up to 8 GPUs used for crypto mining back when nobody knew what bitcoin was) which I sold within 8 months because China started sending their cheapos over. I wasn't fond of my welds with that thing anyway.

But you are right about steel for the most part. I've been looking at both steel and aluminum. The rack is very large, will go on a Econoline van from the front to the back, will have some lights mounted in front, some solar panels, and cut-out for the vent (not planning for anything extra heavy duty.) The quotes I received were $1,500 to $2,700 so it easily pays for my Tig setup and gives me a chance to do something I like.

I am in the process of laying down the plans, but it's a side project and I'm busy with other things momentarily. Once I figure out the total linear feet of material I'll have a better understanding of cost and weight. And of course, I will buy scrap tubing to practice on prior to purchasing main material (just to make sure it's doable.)

Thank you for the thoughtful input!

TigTag wrote: The main reason I'm getting a tig welder is to be able to fabricate an aluminum roof rack for my van. Not sure of the exact wall thickness of tubbing but an initial search yielded the following results for 1.25 diameter: 0.065, 0.095, 0.12 inches. I might not go for the 0.065 but at the same time don't want to omit the option just because my welder can't go low enough in amperage.

Cheers!

I'm really not saying this to be rude (honest), but I don't think there is a reasonable chance this is going to work out in anything short of a very extended timeline. Barring something really extraordinary, it takes folks a while to get the basics of TIG down welding steel, which is easy. Aluminum is simply more challenging. Many people struggle just to get a puddle going at first. Once you get a puddle started you have to keep a very tight arc (except you have to lengthen that arc as you add filler, then close down again), you have to move much faster and your hand feeding the filler rod has to be waaaay faster.

I bought my first TIG welder in 2013 and about 18 months ago I finally decided it was time to try aluminum. I had a very experienced friend stop by and give me a short lesson, then I spent 30 minutes to two hours practicing almost every day for months. That was simply running beads on 1/8" to 1/4" material, then learning edge welds, fillet welds, etc...mostly on 1/8" material. I had piles of L-shaped sections that started out as two pieces of flat stock. I'm now to the point where I really like welding aluminum, but I'd be worried if I had to tackle that project with something like .065 tubing....and I've got some fairly expensive machines.

You're talking about learning a fairly challenging technique and trying it on material that would challenge quite a few people with some experience....just a fair warning!

Thank you so much for taking the time to reply with your experience G-ManBart.

I can't say I was planning on 0.065 tubing

And if it ends up being too difficult I can switch material. But I'm willing to give it a try. Down the road I'd regret not trying it rather than trying it and learn it didn't work.

I really wish I was good with a camera because it would be a great youtube video series of my progress, but I'm never in front of the lens.

TigTag - take this for what it's worth.

Buy the welder. Practice some. Build what you want, from the material you want. Fcuk it; it doesn't require consent from anyone other than your wallet.

Sure, to make great looking welds on small diameter tubing of any material is challenging to do. I venture most on this forum, Pro, Semi-pro or Hobbyist alike would be challenged to make Instagram welds on it. Just take your time, do some practice, and try it when you're ready.

Welding a learned skill, but for things like you are doing, it is not rocket science or brain surgery. Me, personally, I would say MIG for 1" - 1.5" tubing is far more challenging to get right. Wire spits whether you move or not. TIG, you control the puddle size and position. And MIG would be a weaker joint with multiple stops-starts.

The best advantage for using ally for your rack is the lack of corrosion on the mounting plates to the van. Ally-to-steel contact if sealed properly, won't corrode in the same way steel-to-steel would. Plus the weight difference is meaningful given the intention of putting PV panels up there, because they are not light either.

So now you have it from all sides. Up to you, buy what you want, build what you want. Whichever way you go, practice and some effort will yield you something you are proud of and pleased with.

cj737 wrote:Buy the welder. Practice some. Build what you want, from the material you want. Fcuk it; it doesn't require consent from anyone other than your wallet.

CJ leaves out one important point: Is it more important to you to buy a TIG welder and master aluminum, or is it more important to you to actually build a roof rack? If the latter, then there is plenty of objective evidence showing you will get there much more quickly using steel and MIG. If your objective is the former, then great, buy the TIG welder, and enjoy!

Pics attached are a little laundry cart/folding table I build for my wife, out of 1 inch steel square tube. It was cut on a $200 Harbor Freight band saw, and welded together with my Hobart Handler 190. The whole thing took about 8 hours to build, and I am sure other people could build it much quicker. I strength tested it by having 600 lbs of men sit/stand on it. Not very scientific, I admit, but it seems strong enough for my needs. You are not going to do this in 8 hours with aluminum for quite a while, and honestly I am not sure I could either. And blowing through with the MIG was a non-issue. This stuff was .08 inch wall thickness IIRC. Pretty simple to build, really. The cart weighs approximately 40 lbs as it stands, finished.

cj737 wrote: Welding a learned skill, but for things like you are doing, it is not rocket science or brain surgery. Me, personally, I would say MIG for 1" - 1.5" tubing is far more challenging to get right. Wire spits whether you move or not. TIG, you control the puddle size and position. And MIG would be a weaker joint with multiple stops-starts.

The best advantage for using ally for your rack is the lack of corrosion on the mounting plates to the van. Ally-to-steel contact if sealed properly, won't corrode in the same way steel-to-steel would. Plus the weight difference is meaningful given the intention of putting PV panels up there, because they are not light either.

Yes, I think it's that control that I'm after. Having only tried stick and the aluminum spool gun, I now seek to experience that control which was lacking in the other two methods. BTW, I don't post anything on instagram. Perhaps I will make my first post be a picture of the two Coke cans welded together. Yes. The burn-throughs will have identical shapes as the tears I'm crying because I can't weld

And it didn't cross my mind about the corrosion benefit - good thinking!

Louie1961 wrote:

cj737 wrote:Buy the welder. Practice some. Build what you want, from the material you want. Fcuk it; it doesn't require consent from anyone other than your wallet.

CJ leaves out one important point: Is it more important to you to buy a TIG welder and master aluminum, or is it more important to you to actually build a roof rack? If the latter, then there is plenty of objective evidence showing you will get there much more quickly using steel and MIG. If your objective is the former, then great, buy the TIG welder, and enjoy!

Pics attached are a little laundry cart/folding table I build for my wife, out of 1 inch steel square tube. It was cut on a $200 Harbor Freight band saw, and welded together with my Hobart Handler 190. The whole thing took about 8 hours to build, and I am sure other people could build it much quicker. I strength tested it by having 600 lbs of men sit/stand on it. Not very scientific, I admit, but it seems strong enough for my needs. You are not going to do this in 8 hours with aluminum for quite a while, and honestly I am not sure I could either. And blowing through with the MIG was a non-issue. This stuff was .08 inch wall thickness IIRC. Pretty simple to build, really. The cart weighs approximately 40 lbs as it stands, finished.

Nice table! I love making something like this - purposely built to specific dimensions (I'm sure you could have bought one which could work, but not fit quite as nice as a custom one you made.) And that brings me to answer your question in regards to the reason I'm buying a Tig - to master welding aluminum or build the rack - it's neither, and both. Because this project came up, it's a good excuse to get one and try it out. I will hopefully learn how to Tig weld AND get this project done. And I'll get more use of it down the road.

It's a lot like your welder and table. I'm sure you weren't thinking of buying the welder JUST to build the table. I'm sure it allowed you to learn welding AND brought you savings each time you used it on a project.

Anyhow, this thread turned very informative for me, and I appreciate everyone's points of views!

It's a lot like your welder and table. I'm sure you weren't thinking of buying the welder JUST to build the table. I'm sure it allowed you to learn welding AND brought you savings each time you used it on a project.

Just the opposite really. I learned to gas weld and stick weld as a teen. I bought a TIG welder because of all mystique and hype you read, and I am pretty good with it. None the less, I am now selling all my welders to buy a Multimatic 255. I think out of all my projects I have used the stick welder once and the TIG welder 3-4 times. Everything I do is wire feed now, its just so darn handy. I have never fabricated a project with aluminum and really for my needs I probably never will. On top of that, TIG is just way to slow for what I build and frankly a bit of a pain in the butt when tacking and such. I would much rather just point the gun, pull the trigger and be done. With the mutimatic 255 I can do that for both steel and aluminum. But hey, to each, his own as they say.

Tig Tag, I’ve had a Tig welder for about 4 months now and I’m glad I got it. I had mig welding experience before I got my prime weld 225 but I’m glad I have learned and am still learning how to Tig weld. It took me about 3 weeks of practicing 3-5 times a week to lay some decent welds on aluminum. As far as what the prime weld is capable of, well.... in A/C as low as mine will go is 20 amps. As far as it starting hot, I’m not sure if mine does that or not. It’s all together possible that the people saying that it happens are getting a pool going with more amps than are needed to carry a puddle( I do exactly this) and then needing to back off when moving through the weld. Also keep in mind that as your welding your heating the entire piece more and more as you go and that is amplified furthermore on thinner materials and it even seems more so on aluminum. It’s all together possible that mine does start hot and I haven’t noticed it due to lack of experience and it’s the only machine I’ve used for the process. I’ve practiced a bunch on .095 aluminum and that welder does just fine on that thickness material. 20 amps is low enough to keep an arc without a puddle on .095 aluminum. So your starts and stops with be fine if you choose to use the swirling method at the end of a weld. I looked at a bunch of welders before I bought mine and continue to look as I learn more. It seems to me that most affordable inverter Tig machines and some of the more expensive ones have minimum amps at or above 20 amps. With enough practice I honestly think you could weld .065 with my welder but I don’t have any material that thin to try. I hope this helps with your decision on the purchase of a welder and your roof rack project.


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walz10 wrote:... 20 amps is low enough to keep an arc without a puddle on .095 aluminum. So your starts and stops with be fine if you choose to use the swirling method at the end of a weld. I looked at a bunch of welders before I bought mine and continue to look as I learn more. It seems to me that most affordable inverter Tig machines and some of the more expensive ones have minimum amps at or above 20 amps. With enough practice I honestly think you could weld .065 with my welder but I don’t have any material that thin to try. I hope this helps with your decision on the purchase of a welder and your roof rack project.


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waltz10, your input is very much appreciated! You've answered some of the specific details I was looking for. You actually phrased it very well when you said that 20 amps is low enough to keep an arc without forming a puddle in 0.095 material - this really helps me understand that 20 amps is low enough and at this point is more about the operator experience.

I actually had to go back to my notes because I remember the Primeweld starts at 10 amps the lowest. I just search again online and all the websites giving the specs say 10-225 amps. Either way, I've narrowed it down to 2 welders, Primeweld being one.

Thank you again!

TigTag wrote:
I actually had to go back to my notes because I remember the Primeweld starts at 10 amps the lowest. I just search again online and all the websites giving the specs say 10-225 amps. Either way, I've narrowed it down to 2 welders, Primeweld being one.

One thing to check is that minimum running amps are often lower than minimum starting amps. It's not unusual to see a machine with a 10A minimum listed but the starting minimum can be 20A or more. Unfortunately, Primeweld doesn't have their user manual listed, and they don't put out much in the way of specs so it's not clear what the actual numbers are.

My recommendation: Less typing. More welding.

Hood down. Arc lit.

10 minutes of that will teach you WAY more than 100 hours of reading forums or making spreadsheets comparing welders.

Buy a welder that meets your basic needs. Any welder. And then start welding.

Spartan wrote:My recommendation: Less typing. More welding.

Hood down. Arc lit.

10 minutes of that will teach you WAY more than 100 hours of reading forums or making spreadsheets comparing welders.

Buy a welder that meets your basic needs. Any welder. And then start welding.

Amen!

Nailed it !! The ONLY way to get into the pool .

There’s some good advice given here. Get a machine and do some welding. It’s my opinion that the prime weld will serve you well and it a good value considering the options, accessories and support that you get with it. Keep in mind that it’s not a $3000 machine and doesn’t have the same conveniences that a machine of that price range will have. Don’t forget to get a good hood to go with your new welding machine. Then hunt down some material to practice on some argon and get with it.


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