Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
Bill Beauregard
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noddybrian wrote:In pictures that model though basic appears to have slope down so it's still possible to get away without a pedal hitting the initial amps hard then using the downslope as a kinda pulse.
If you ski, you will understand. I've never mastered slalom skiing. I can't plan turns to match the gates.
A pulse requires you to sync your actions to the pulse in the welder. You can adjust the rate of pulse. I've never managed to synchronize dipping with the machine. Pulsing with my foot is a great deal easier for me.

Choosing a higher rate of pulse, I feel is a great way to limit the heat input while heating the weld to an adequate energy level.
noddybrian
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Well I don't ski either & have general coordination problems plus my damaged left hand has a mind of it's own - the more I concentrate the worse it gets - for me using a pedal just complicates the issue so I only use one as a last resort - ( mostly on thin aluminum ) & I hate them - am considering one of the pressure sensitive torch switch amptrols instead but the price is crazy high still -I do know what you mean with the pulse timing thing - though I find that easier than using a pedal - my point to the OP was that you can weld without a pedal on aluminum just not continuously - with slope down set the main amps high enough to get a puddle fast - add filler quickly before it gets too big / out of control & start to wash forward while tapering off with the slope down - once the amps get low enough the puddle solidifies hit the switch blast it again & move forward - pretty much as you would bump weld on anodized - some of the nicest welds you will see on here were done that way on boat railings - not even sure if the guy has a pedal available & the shape / size of his projects would make using one very difficult - others love the pedal & struggle to weld without it - that's why we are all different but still get the job done.
cj737
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noddybrian wrote:...once the amps get low enough the puddle solidifies hit the switch blast it again & move forward - pretty much as you would bump weld on anodized - some of the nicest welds you will see on here were done that way on boat railings - not even sure if the guy has a pedal available & the shape / size of his projects would make using one very difficult...
This is the exact technique I use often with ally when the shape, material or position requires real control. I don't have a torch switch, but whack the pedal, use pulse (often 1.2pps, 50% on time, 20% peak) to get fast chill. Its almost like making a bunch of single hot tacks with no start or re-start.
Last edited by cj737 on Wed Feb 14, 2018 9:43 am, edited 1 time in total.
Bill Beauregard
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There are some new torch mounted amperage controls out now. I don't have one, but some welds would benefit. I manage usually to rig a foot pedal to serve the purpose.
musccoo
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noddybrian wrote:my point to the OP was that you can weld without a pedal on aluminum just not continuously - with slope down set the main amps high enough to get a puddle fast - add filler quickly before it gets too big / out of control & start to wash forward while tapering off with the slope down - once the amps get low enough the puddle solidifies hit the switch blast it again & move forward - pretty much as you would bump weld on anodized
Ahhhh I get ya makes sense I'll give it a go!
musccoo
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So finally got a chance to have another go.. I bought a foot pedal and wow what a difference.

I found that tungsten size seems to make a huge difference with alloy. Some 3/4mm alloy I was using a 2.3mm tungsten but intercooler piping I couldn't even get a puddle going properly so had to use the 1.6mm tungsten. Maybe this is beginner error I'm not sure. Also cup size, I had just been rocking my 8 gas lens that I use for stainless. I put the standard collet body back in with a 4 and seemed to be much better.

Nonetheless my results were much better than first attempt.

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I tried welding some intercooler pipe to the thicker stuff at the end, I found that it was just making a mess with the 2.3mm tungsten so I had to use the smaller 1.6mm. Its a bit messy, but its a start.. (it looks dirty cause of my first weld practice lol but it was clean I gave it a good go over with acetone first)

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musccoo
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Been doing some more practice, stuff for a friend. Gave the old cast a go, not the cleanest on the sump, but doesn't leak so I guess it worked? haha

Using 2% lanthanated 2.3mm for everything

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cj737
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Looks much better. With respect, that extension on the turbo, you may find it will crack during operation due to the heat shrink/expansion. One method to avoid that is to bevel both pieces to a fine point so you can get 100% penetration without intruding on the ID.

Also, flow argon over the weld after you weld to aide in cooling the ally and preventing contamination from entering the weld while its hot. You may need to make 2 passes depending upon the thickness of the tubing, and if so, stagger your start/stop to avoid aligning the weld ends.
musccoo
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cj737 wrote:you may find it will crack during operation due to the heat shrink/expansion
Ah yeah, I was hoping cause it doesn't have any stress (weight - only a filter) on it, it might be ok so I didn't bother bevelling it out ( I def thought it about it), but what you say about heat is a good point.

It it breaks I'll do it again with a bevel :)

Thanks for the tips appreciate it
Darrin
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musccoo wrote:
cj737 wrote:you may find it will crack during operation due to the heat shrink/expansion
Ah yeah, I was hoping cause it doesn't have any stress (weight - only a filter) on it, it might be ok so I didn't bother bevelling it out ( I def thought it about it), but what you say about heat is a good point.

It it breaks I'll do it again with a bevel :)

Thanks for the tips appreciate it
That,or heat treat it depending on the base material, small enough to fit in an oven. Easy enough to find the temps required and times for different alloys.......just do it when the missus is away....!!!!
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